How Accurate are Apple Watch Calories?

The Apple Watch has become one of the most popular fitness tools globally, tracking everything from heart rate to step count and calorie burn. But just how accurate is the Apple Watch calories estimate? Should you use Apple Watch calorie data to guide training or nutrition decisions? 

For everyday exercisers and personal trainers, understanding Apple Watch calorie accuracy is important. This article explores how the watch calculates calories, what affects those calculations, and how to make the readings as reliable as possible. 

How accurate is the Apple Watch for calories?

When it comes to calorie tracking, the Apple Watch performs reasonably well, but not perfectly. 

Several independent studies have found that while the Apple Watch’s heart-rate tracking is impressively accurate — often within 4–5% of laboratory measurements — the calorie burn estimates can vary much more widely. 

One peer-reviewed study found that Apple Watch calorie burn readings were off by 27–30% compared to gold-standard laboratory measures such as indirect calorimetry. Interestingly, a 2025 meta-analysis found that the Apple Watch underestimated energy expenditure in men but overestimated it in women. 

Research indicates that the Apple Watch may track energy expenditure more accurately for steady-state activities such as walking or running outdoors, where motion and heart rate data are clear and consistent. Accuracy tends to decline for resistance training, HIIT, or sports that involve variable effort and wrist movement, such as tennis or gymnastics, as calorie burn for these types of activity is harder to interpret from motion and heart-rate data alone. 

In simple terms, the Apple Watch provides a useful ballpark estimate for total calories burned, but should not be considered a precise scientific measurement.

How calorie tracking works 

To understand where the differences in calorie estimates come from, it helps to know how the watch calculates energy expenditure. The Apple Watch estimates calories using a combination of: 

• Personal data: age, sex, height, and weight 

• Heart rate data: recorded continuously via optical sensors 

• Motion data: accelerometers and stride length for pace, and barometers detect inclines  

These inputs are run through proprietary algorithms to predict total energy expenditure (TEE) — the sum of your resting metabolic rate and calories burned during activity. 

Because the calculations rely on averages and population-based models, any individual whose body composition or physiology differs from those averages may see less accurate results. This is why measuring your metabolism directly (either through an RMR test or DEXA scan) can provide so much value when tracking calories. 

How Apple Watch estimates calorie burn at rest

When not exercising, the Apple Watch primarily estimates calorie burn from resting metabolic rate. This is the energy the body uses to maintain vital functions like breathing, circulation, and temperature regulation. 

RMR is estimated based on your entered height, weight, age, and sex. For most people, this is fairly accurate, but if your lean muscle mass is much higher or lower than average for your body size, the estimate may miss the mark. There are also a variety of medications and medical conditions that can alter your RMR, such as hypo/hyperthyroidism, heart failure and taking insulin. 

Factors that affect Apple Watch calorie accuracy

Several factors can influence how close your Apple Watch calorie estimate is to reality. Make sure to keep the following in mind when using your Apple Watch to gauge your calorie burn throughout the day and during exercise. 

Workout app tracking

Selecting the correct workout type in the Workout app ensures the watch uses the most suitable algorithm for that activity. Logging a “HIIT” session as a “Walk” or “Other” can significantly change the calorie calculation.

Watch calibration

Calibrating your watch improves accuracy for movement and distance tracking, which feeds directly into calorie calculations. Apple recommends a 20-minute outdoor walk or run with GPS enabled to allow the watch to learn your stride length and typical heart-rate patterns.

Heart rate accuracy

Optical heart-rate sensors are generally reliable, but readings can be affected by poor wrist contact, sweat, or wrist movement. A snug fit just above the wrist bone gives the best results.

VO₂ Max and fitness level

Newer Apple Watch models estimate VO₂ Max from heart-rate trends. Because energy expenditure depends partly on cardiorespiratory fitness, inaccuracies in this estimate can lead to errors in calorie tracking, especially for highly trained individuals. 

Body composition 

Since the Apple Watch uses body weight and not lean mass, people with higher muscle mass may burn more calories than predicted, while those with higher body fat may burn fewer. This is one reason why two individuals of the same weight can get different calorie burns for the same workout.

How to maximise the accuracy of your Apple Watch calories 

Although no wearable is perfectly precise, there are a few steps you can take to make Apple Watch calorie tracking more consistent and useful.

Calibrate your Apple Watch regularly

Go for a 20-minute outdoor walk or run at a natural pace with GPS enabled and the watch worn snugly to calibrate your Apple Watch. Repeat every few months or when your fitness changes significantly.

Get an RMR Test or DEXA scan to establish a baseline RMR

For those who want more accuracy, a DEXA body composition scan or RMR test provides a true baseline for daily energy expenditure. Knowing your actual RMR allows you to compare it with your Apple Watch estimate and adjust expectations accordingly. 

If body recomposition is your primary reason for tracking calories with the Apple Watch, then getting multiple DEXA scans will give you insights (to the gram) of changes in your fat mass and muscle mass. 

Tracking your body composition is particularly important if you’re losing weight with GLP-1 medication, as substantial changes in lean mass (alongside fat mass) can impact your resting metabolic rate and, by extension, your calorie requirements. 

Choose the correct workout type

Always select the workout mode that best matches the activity, so the device applies the right algorithm. Avoid generic “Other” modes when possible.

Keep personal data up to date 

Regularly update weight, height, age, and other personal information in the Health app. Even small changes in body weight can alter calorie predictions.

Wear it properly

Ensure the watch is snug, especially during workouts, and avoid placing it too high or too loose on the wrist. Good sensor contact improves both heart-rate and calorie accuracy.

Conclusion: How accurate is the Apple Watch calorie estimate, really?

The Apple Watch calorie burn tends to be within 15–30% of true energy expenditure. That means if your watch shows 500 active calories burned, the actual value could fall anywhere between roughly 350 and 650. 

While this range sounds wide, it’s still useful for tracking trends. If your weekly calorie burn is rising, or your activity rings are closing more easily, those relative changes are likely real, even if the absolute number is off. For personal trainers, this means the Apple Watch is a great motivational and progress-tracking tool, but not something to base precise nutrition targets on without further data.

If you’re looking to gain precise insight into your resting metabolic rate to hit your weight loss or body recomposition goals this year, booking an RMR test or DEXA scan is the best place to start.

If you’ve ever finished a run and seen your Garmin flash up with a new VO₂ Max estimate, you’ve probably wondered: how accurate is the Garmin VO₂ Max, really? 

VO₂ Max, or maximal oxygen uptake, is often described as the gold standard for cardiovascular fitness. It indicates the maximum amount of oxygen your lungs can inhale during maximal exercise and is strongly linked with endurance performance, longevity, and recovery capacity. 

Garmin watches use algorithms to estimate this value from your workouts — but how close is that number to the truth? In this article, we’ll unpack what VO₂ Max actually measures, how Garmin calculates VO₂ Max, and where the differences arise between real laboratory testing and fitness tracker estimation.

What is VO2 Max?

VO₂ Max stands for maximal oxygen consumption or the maximum volume of oxygen your body can utilise per minute, per kilogram of body weight (ml·kg⁻¹·min⁻¹). 

In simple terms, it’s a measure of how well your heart, lungs, and muscles work together to deliver and use oxygen during exercise. A higher VO₂ Max means your body can generate more energy aerobically, allowing you to sustain harder efforts for longer. 

Several factors influence your VO2 Max:  

• Heart function (stroke volume, cardiac output) 
• Lung capacity 
• Muscle mitochondrial density 
• Capillary network and oxygen delivery 
• Genetics and training status 

VO₂ Max is widely used in sports science and clinical settings to assess aerobic fitness, cardiovascular health, and endurance potential. 

How is VO2 Max measured?

In a laboratory setting, VO₂ Max is measured by direct gas analysis during an incremental exercise test, typically on a treadmill or bike ergometer. 

During the test: 

• You wear a metabolic mask connected to a machine that analyses every breath you take. 
• You exercise at a gradually increasing workload until you reach volitional exhaustion. 
• Throughout the test, the equipment measures oxygen consumption and carbon dioxide production in real time. 

The point where oxygen consumption plateaus despite increasing effort is your true VO₂ Max. 

A lab-based VO₂ Max is the only way to directly measure your VO₂ Max score. Everything else, including Garmin, Apple, Fitbit, and Polar estimates, uses prediction models. These models are based on correlating measurable inputs with lab-measured VO₂ Max data. 

Can my Garmin watch measure VO2 Max?

Not exactly — and this is the crucial point. 

Your Garmin cannot measure VO₂ Max because it doesn’t analyse your oxygen or carbon dioxide exchange. Instead, it estimates VO₂ Max using algorithms developed by Firstbeat Analytics (a company owned by Garmin). 

These algorithms are based on correlations between specific, easily-measured metrics (including heart rate, speed, power output, and training history) and the VO₂ Max values recorded in the lab tests of thousands of athletes. Using these data points, Garmin estimates where you might sit on the VO₂ Max scale. While the reading can be a useful trend indicator, it’s not a direct measurement of your physiology. 

So what is my Garmin tracking?

Garmin watches are highly sophisticated movement trackers. They can accurately record: 

• Steps and cadence 
• Heart rate  
• Speed, distance, elevation (via GPS and barometer) 
• Training load and recovery metrics 

However, they can’t see what’s happening inside your body. 

They infer aerobic capacity by observing the relationship between your pace and heart rate and assume that lower heart rates at faster speeds indicate better oxygen utilisation. 

That assumption is largely based on average, but it depends heavily on the data Garmin has been trained on, and how closely you match those test populations. 

For instance, if Garmin’s reference subjects were mostly young male endurance runners, but you’re a 45-year-old recreational triathlete, the algorithm may not represent you perfectly.

How accurate is the Garmin VO2 Max estimate? 

Here’s where we get to the heart of the question: how accurate is Garmin VO₂ Max? 

Research comparing Garmin (and other fitness-watch estimates) to laboratory measurements suggests that accuracy varies depending on conditions, activity type, and user characteristics. 

1. The correlation problem 

Garmin’s VO₂ Max algorithm is built on correlation models, meaning it assumes that certain patterns of heart rate and speed correspond to specific VO₂ Max levels. 

However, correlations depend on how similar your training environment and physiology are to the model’s dataset. 

If you run on hilly terrain, uneven surfaces, or in varying weather, your pace-to-heart rate relationship will change. Similarly, if you train mostly in zones affected by fatigue, dehydration, or stress, your readings can be skewed. 

In lab conditions, everything is controlled, including treadmill gradient, air temperature, calibration, and motivation. On the road, none of those factors is standardised. 

2. The variability of sensors 

Optical heart rate sensors (those flashing green lights on your wrist) are far less reliable during movement than chest straps. Motion artefact, skin tone, sweat, and tightness of fit can all affect readings. Even a small heart-rate error can shift VO₂ Max estimates by several points. 

3. The algorithm assumptions 

Garmin’s algorithm assumes that your maximal effort data is representative of your aerobic potential. But if you never hit true maximal effort in training (e.g., because you train below threshold), Garmin may underestimate your VO₂ Max. 

4. How close does the Garmin VO₂ Max estimate get? 

Independent studies comparing Garmin’s VO₂ Max estimates to laboratory tests show mixed results. In trained runners, using consistent outdoor runs, Garmin can come surprisingly close — often within approximately 5% of lab-measured values. In recreational users or in less controlled conditions, the gap widens to around 10–15%. Finally, for cyclists, accuracy tends to drop further still unless a power meter is used.  Garmin’s VO₂ Max is a reasonably good estimate for tracking trends, but not a replacement for a lab-based measurement. 

If your Garmin says 52 ml·kg⁻¹·min⁻¹, and you’re not running in consistent conditions, your true VO₂ Max might be anywhere between 44 and 60. While this can help track the overall trend of your aerobic fitness, it isn’t as accurate as a lab-based VO₂ Max test.  

Should I track my Garmin VO2 Max? 

Absolutely, but for the right reasons. 

The true value of Garmin’s VO₂ Max metric isn’t in the number itself; it’s in the trend. 

If your Garmin VO₂ Max is steadily increasing over weeks or months, it’s a reliable sign that your aerobic fitness is improving, even if the absolute number isn’t exact. 

You can use it to: 

• Monitor long-term progress in aerobic capacity 
• Evaluate training load and recovery balance 
• Spot overtraining or fitness plateaus 
• Motivate consistent effort 

The key is consistency. Track your Garmin VO₂ Max over similar runs (same route, pace, conditions) to get the most reliable data. Used consistently, evidence shows that the Garmin watch provides a valid  VO₂ Max when a lab-based test isn’t available. 

What are the advantages of getting a lab-based VO2 Max test?

A lab VO₂ Max test remains the gold standard for a reason, as it provides direct, personalised, and actionable data that wearable devices can’t replicate. 

At My Vital Metrics, VO2 Max testing involves: 

• Direct gas analysis of oxygen and carbon dioxide 
• Heart rate and ventilatory thresholds 
• Zone-based training recommendations 
• Fuel utilisation metrics 

Key advantages include: 

• Precision: Real physiological measurement rather than estimation. 
• Personalisation: Training zones based on your actual ventilatory thresholds. 
• Context: Integration with your body composition, RMR, and recovery data. 
• Repeatability: Controlled environment for accurate before-and-after comparisons. 
• Motivation and feedback: Objective insight into cardiovascular efficiency and potential improvements. 

For athletes, this means you can target specific intensity zones (Zone 2, threshold, VO₂ intervals) to maximise training efficiency. For recreational runners, it offers a clear picture of your aerobic health, not just a number on your wrist. 

VO₂ Max, longevity, and healthy ageing 

Beyond athletic performance, your VO₂ Max is one of the strongest known predictors of long-term health and lifespan. Research which analysed over 122,000 adults found a clear relationship between cardiorespiratory fitness and all-cause mortality, with no upper limit to the benefits. Those in the highest fitness category had an 80% lower mortality risk compared with the least fit group. 

In practical terms, maintaining or improving your VO₂ Max through regular aerobic training not only boosts endurance but also supports metabolic health, cardiovascular resilience, and healthy ageing. Tracking VO₂ Max, whether via a Garmin estimate or a lab-based test, therefore offers powerful insight into your long-term vitality.

The Garmin VO2 Max verdict  

Garmin’s VO₂ Max estimates are surprisingly good at tracking trends, but they remain approximations based on population data and indirect correlations. 

Here at My Vital Metrics, we’ve conducted over 1800 VO₂ Max tests. In our experience, customers’ lab-based VO₂ Max scores and the readings on their watch can vary pretty significantly. This can be the difference between someone being classified as having a ‘fair’ VO₂ Max and having an ‘excellent’ VO₂ Max. Your watch is a fantastic tool for monitoring progress and maintaining motivation, but it can’t replace the precision of a lab-based VO₂ Max test.

If you want to truly understand your aerobic capacity, training zones, and how your fitness is evolving, a lab-based VO₂ Max test offers the accuracy and depth you need.

At My Vital Metrics, our VO₂ Max testing uses gold-standard gas analysis to provide you with a full physiological profile — the same technology used in elite sports and research labs. Book your lab-based VO₂ Max test today to see how your real numbers compare to your Garmin and take your training to the next level.

When it comes to body composition, there’s plenty of misinformation. It’s easy to be misled by outdated, contradictory, or entirely incorrect information, and this can lead to stalled progress and unnecessarily extreme diet and exercise habits. 

In this article, we’ll dispel 5 common body composition myths and misconceptions to make sure you have the know-how you need to reach your body comp goals safely and effectively.  

Body composition myth-busting 

From extreme diets to dubious supplement recommendations, the internet is packed full of unscientific advice on how to lose fat and gain muscle. However, alongside these more extreme claims, there’s still plenty of genuine misunderstanding about the basic processes that power body recomposition. The 6 body composition myths below fall into that category – let’s take a look. 

Myth: You can turn fat into muscle

One of the most common body composition myths is that you can turn fat into muscle, or vice versa. Body recomposition is often discussed as though it were a singular process, but it’s actually two distinct processes: fat loss and muscle gain. 

Fact: Fat and muscle are different tissues, and building muscle is a separate process to burning fat 

Fat loss

Losing fat requires a calorie deficit (consuming fewer calories are used through everyday activity and burnt through exercise). A calorie deficit prompts the body to utilise alternative forms of energy, breaking down tissues to fuel key bodily processes.

In a calorie deficit, the body initiates the breakdown of fatty tissues into fatty acids through a process called lipolysis. These fatty acids enter the bloodstream and are further metabolised into additional compounds (such as ketones) which serve as a source of fuel when nutritional intake is low. This process facilitates weight loss through the “burning” of fat for energy. At no point is this fat used to form new tissues such as muscle, even if you’re working out. 

Muscle gain

On the other hand, building muscle requires a calorie surplus (consuming more calories than are used) and progressive challenge to muscles through strength or resistance training. When these conditions are met, muscle hypertrophy (an increase in muscle mass) is possible. 

Of course, it’s a little more complicated than that, with plenty of other factors coming into play. Training type, volume, load, sleep quality, nutrient timing, and protein intake all play a role in successful muscle gain. However, crucially, strength training will not “turn” fat into muscle. Rather, when combined with a caloric surplus and adequate protein intake, strength training will help build new muscle and increase your overall muscle mass. 

Myth: You can spot reduce fat 

Contrary to popular belief, you can’t choose where you burn fat first (or last). The idea of spot reduction of fat appeals to many, and may seem intuitive. After all, for muscle development, if you want big shoulders, you need to work your shoulders. 

Fat loss is not like this, though. Fat is a fuel source for the whole body, and when the body burns fat, this is broken down from where the metabolism wants to break it down, sent to the liver for further processing, and then sent around the body for use as fuel. 

Focused strength training can build muscle in a specific area (for example, the legs), which can add shape and lend you a leaner appearance, but exercise alone will not lead to a reduction in fat in the area.

Fact: You can’t choose where you lose fat first, but you can work towards losing overall body fat

Where we store fat and how this fat is lost during a calorie deficit is largely determined by genetics and hormonal state. For example, people with a higher level of testosterone will tend to store more fat around the midsection, while those with more estrogen will tend to store more fat around the hips and thighs. While all physical activity helps to boost your calorie burn, you won’t necessarily see fat lost from the areas you’re hoping for first. 

As an example, core workouts are a popular method of building core strength. Incorporating core work into your workout routine is a great way to build strength in your abdominals, obliques, pelvic muscles, and lower back, and build a firm foundation for other compound movements. However, these exercises won’t burn fat from your stomach area or automatically lead to six-pack abs if your body fat percentage is higher. This doesn’t mean these exercises aren’t worth incorporating; however, you should aim to be realistic about what they can and can’t do for your body composition. 

Myth: Cardio is the best way to burn fat 

Cardiovascular exercise such as walking, running, swimming, or cycling is a fantastic way to improve cardiovascular health. Cardio helps improve your speed and stamina, reduces your risk of certain chronic conditions, boosts your mood, and has a whole host of other health benefits. However, contrary to common belief, it is not an efficient way to burn fat. 

Fact: A combination of diet, cardio, and strength training is the key to sustainable fat loss 

To understand why cardio alone isn’t the best strategy for fat loss, it’s important to understand why it’s many people’s go-to exercise for weight loss. 

Cardio exercise is a common fat loss strategy because it has a relatively high-calorie burn. For example, if a 155lb adult ran at a 6mph pace (a 10 min mile) for 1 hour, they would burn a total of 704kcal. If that same person did a vigorous weight lifting workout for 1 hour, on the other hand, they would burn a total of 422kcal. From this comparison alone, it would seem that the run is a better weight loss strategy than the strength workout. 

However, what this calculation doesn’t take into account is that both cardio and strength training affect more than pure calorie burn. 

Weight training helps to build muscle mass, which in turn increases metabolic rate, burning more calories over time. Additionally, the metabolic effects of weight training aren’t limited to the time you’re exercising – calorie burn remains higher after your session to aid muscle repair. 

Over time, incorporating strength or resistance training into your workout regime is likely to further your fat loss goals through an increase in lean muscle mass and a boosted metabolic rate. Weight training while in a calorie deficit has the added benefit of sending signals to your metabolism indicating that you need these muscles – this means that any deficit will preferentially be taken from fat, not muscle, helping you to maintain muscle mass as you lose fat.

The second key component to sustainable fat loss is nutrition. Even with a routine of cardio and strength training, if you’re not eating in a calorie deficit, you won’t see fat loss. Working to incorporate a moderate calorie deficit to accompany your increased activity level will help you to see the fat loss you’re after. 

Myth: The greater the calorie deficit, the quicker the fat loss

If a calorie deficit leads to weight loss, then a bigger calorie deficit leads to more weight loss – right? 

Well, not always. 

Fact: Too great of a calorie deficit will not lead to faster fat loss – but it can have negative effects

The size of your calorie deficit will indeed affect your rate of weight – and by extension fat – loss. For someone maintaining a calorie deficit of 200kcal, for example, increasing this deficit to 400kcal would likely lead to them experiencing a faster rate of weight loss. 

However, this isn’t true indefinitely. 

In too large of a calorie deficit, the body may burn other tissues, such as muscle (which is costly for the body to maintain), leading to a loss of lean mass. It may also make “compromises” in other areas, limiting the energy it puts into our immune system or brain function. This can lead to a range of unpleasant symptoms, such as getting sick often, feeling cold, and experiencing brain fog. These are all signs that the body doesn’t have enough energy and that your calorie deficit is likely too big. Research recommends that VLCDs (very low-calorie diets) are only suitable for short periods and under extreme circumstances, and are not recommended for routine weight management. Any VLCD should always be carried out under medical supervision.

Maintaining a moderate calorie deficit of 500kcal per day is likely ideal for fat loss without compromising other tissues. Rather than opting for a more extreme diet, aim to hit a reasonable deficit consistently. This will be more sustainable and more likely to lead to lasting fat loss. 

Myth: To lose fat or gain muscle, I can’t eat x

There are plenty of fat loss “food rules” and detailed nutrition guides for muscle gain out there. However, the idea that there’s only one way to eat and train to lose fat or gain muscle is a misconception. 

Fact: Provided you maintain a calorie deficit (for fat loss) or a calorie surplus (for muscle gain), no food is off-limits 

The good news is that there’s no one way to lose weight or put on muscle. What works for one person may not work for you, and while there are best practices you’ll want to stick to (such as getting adequate protein for muscle gain), a lot of the rest is up to personal preference. 

A 2021 meta-analysis of optimal diet strategies for weight loss compared a range of dietary interventions. The study compared low carbohydrate, high protein, low fat, ketogenic, paleolithic, low-GI, intermittent fasting, Mediterranean, Nordic, vegetarian, DASH (dietary approaches to stop hypertension), and portfolio (low cholesterol vegan) diets. 

The analysis concluded that there was no single best strategy for weight loss and that “the best diet for weight management is one that can be maintained in the long term”.

Because of this, while no food or food group is off-limits, you may want to consider eating foods that will make it easier to stick to your calorie deficit. Highly processed foods will leave you lacking in micronutrients like vitamins and minerals, and leave you feeling hungrier sooner. This can make it difficult to stick to a calorie deficit and impact your progress. Consuming a diet that hits all your macro and micronutrient requirements while incorporating plenty of whole foods, quality protein, and fibre can make it easier to stick to your plan long-term.

This highlights the importance of finding a sustainable nutrition strategy that works for you. A calorie deficit is the only truly necessary factor for weight loss; how you choose to go about that, and the specific foods you do or don’t include in your meal plan, is up to you. For the best chance of success in optimising your nutritional intake for fat loss or muscle gain, we’d recommend speaking to a registered dietician to create a plan that’s customised to your body and goals.  

Ready to hit your body recomposition goals?

Hopefully, this article has busted a few body composition myths. If you’d like to learn more about how to lose fat, gain muscle, maintain a healthy body fat percentage, or reach other body composition goals, we’d recommend heading over to the My Vital Metrics blog, where we’ve covered all these topics and many more. 

Here at My Vital Metrics, we understand that access to accurate data is essential to making long-lasting changes to our health and fitness. If you’re looking to make positive changes to your body composition, then a professional DEXA scan is a great place to start. To find out more or book your first scan, reach out to the team at My Vital Metrics today!

In his groundbreaking book, “Outlive: The Science and Art of Longevity”, Dr. Peter Attia takes a deep dive into the science and art behind living a longer, healthier life. Drawing from a wide range of sources, Attia discusses the importance of not only living longer but living better, with a focus on overall health and well-being. This comprehensive guide covers various aspects of longevity, including diet, exercise, mental health, and cutting-edge medical screenings such as DEXA scans and VO2 Max testing – services that we offer here at My Vital Metrics.

The Importance of Longevity and Healthspan

Outlive by Peter Attia emphasizes the significance of not only extending our lifespan but also improving our healthspan – the period during which we maintain optimal health and vitality. Dr Attia argues that the key to achieving this lies in addressing the most common causes of death and chronic illness in the developed world, such as cardiovascular disease, type 2 diabetes, neurodegenerative diseases, and cancer.

By focusing on preventative measures and making informed lifestyle choices, we can reduce our risk of developing these conditions and improve our overall health and well-being. In doing so, we can potentially extend our lives and enjoy a higher quality of life well into our later years.

The Role of DEXA Scans in Longevity

One of the critical health screenings recommended by Dr. Attia is the DEXA scan. DEXA (Dual-Energy X-ray Absorptiometry) is a state-of-the-art imaging technology that accurately measures bone density, body composition, and muscle mass. By providing detailed insights into an individual’s body composition, a DEXA scan can help identify potential health risks and inform personalized health and fitness plans.

Regular DEXA scans can track changes in body composition over time, allowing individuals to monitor their progress and make necessary adjustments to their exercise and nutrition plans. By incorporating DEXA scans into a comprehensive health assessment, individuals can take control of their health and make informed decisions to improve their overall well-being.

Obviously, the DEXA is the cornerstone of the services we offer to clients and is the first go-to measure to get a sense of their metabolic health.

Exercise: A Pillar of Longevity

Dr. Attia highlights the critical role of exercise in promoting longevity and overall health. He advocates for a well-rounded fitness regimen that includes strength training, cardiovascular workouts, and functional movement exercises. By engaging in regular physical activity, individuals can reduce their risk of developing chronic illnesses, maintain a healthy body weight, and improve their overall quality of life.

Our take on this is that it is clearly the correct position, and like Attia, we always recommend a multi-part fitness regime for our clients. For those of us who need to lose fat though, we would go one further and suggest that people have very clear in their minds the role of each part of exercise. Cardiovascular exercise is not there to ‘burn fat’ as most people think of it, but rather to ensure that everything remains working at optimum. Strength training is not there for its calorie-burning effects, but rather to build strength and muscle mass, and so on. By being clear about the role of each we can ensure that all exercise is targeted.

VO2 Max Testing: Measuring Cardiovascular Fitness

Another essential component of a comprehensive health assessment is VO2 max testing. VO2 max represents an individual’s maximum rate of oxygen consumption during intense exercise, providing a measure of cardiovascular fitness. By understanding their VO2 max, individuals can tailor their exercise programs to improve their cardiovascular health and overall fitness. Attia notes that as a single measure, the VO2 max is a better predictor of all-cause mortality than any other. This means that it should not be only athletes who take these intense tests, but all of us. Please note that for certain health conditions, you might need to get clearance from your doctor before you can complete the VO2 max test.

Nutrition: The Foundation of Health and Longevity

Dr. Attia underscores the importance of proper nutrition in promoting longevity and overall health. He emphasizes the need for a high-quality diet that provides adequate protein, healthy fats, and nutrient-dense carbohydrates while avoiding excessive sugar and processed foods. By making informed dietary choices and focusing on food quality, individuals can optimize their health and reduce their risk of developing chronic illnesses.

Sleep: A Critical Factor in Health and Longevity

A good night’s sleep is essential for overall health and well-being, and Dr. Attia highlights its significance in promoting longevity. Poor sleep quality and insufficient sleep duration have been linked to various health problems, including obesity, cardiovascular disease, and cognitive decline. By prioritizing sleep and adopting healthy sleep habits, individuals can improve their overall health and well-being.

Mental and Emotional Health: The Missing Piece

Dr. Attia discusses an often-overlooked aspect of promoting longevity: mental and emotional health. He emphasizes the need for individuals to address underlying mental health issues, develop healthy coping mechanisms, and prioritize self-care. By focusing on mental and emotional well-being, individuals can improve their overall quality of life and increase their chances of living a longer, healthier life.

Comprehensive Health Screenings: Taking Control of Your Health

Dr. Attia advocates for a proactive approach to healthcare, emphasizing the importance of comprehensive health screenings to identify potential health risks and inform personalized health plans. In addition to DEXA scans and VO2 Max testing, these screenings may include cholesterol testing, functional movement assessments, and other specialized tests.

Conclusion: Taking Control of Your Health and Longevity

In summary, Dr. Peter Attia’s “Outlive” offers a comprehensive guide to promoting longevity and overall health. By addressing the most common causes of death and chronic illness, adopting a well-rounded exercise regimen, focusing on proper nutrition, prioritizing sleep, and addressing mental and emotional well-being, individuals can take control of their health and increase their chances of living a long, healthy life.

It should be clear by now that we would absolutely stand behind him on all his suggestions for a path to being a centenarian, but we would say that of course.

For those in the UK seeking to take control of their health and optimize their chances of living to 100 and beyond, there are very few companies that offer many of the services recommended by Dr. Attia, but we are fortunate and proud to be one of them.

Here at My Vital Metrics, the tests we offer include DEXA scans, VO2Max testing, cholesterol testing, functional movement assessments, and more. By taking advantage of these cutting-edge health screenings and implementing the strategies outlined in “Outlive,” individuals can make informed decisions about their health and work towards a longer, healthier life.

We do think that Dr Attia’s book is so important, we are going to do a bit of a series of blog articles to cover different aspects of the testing we do and how it relates to his suggestions.

The benefits of exercise are hardly a secret. From losing weight to lowering blood pressure and reducing stress, the positive effects of working out are well-known. 

However, what many people don’t realise is just how significant of an impact exercise can have on our lives. With just 20-30 minutes of exercise each day, you can improve your mental health, increase physical strength, and boost your energy. Not only will exercise positively affect almost every aspect of your life, but it’ll also help you feel great! 

If you’re looking to start exercising more or would like to get back into it after a break, keep reading for some great tips on how to reap the benefits of exercise. These incredible short-term and long-term benefits of exercise are sure to provide some workout motivation!

‍The science behind the benefits of exercise

A comprehensive meta-analysis evaluated the benefits of exercise on energy levels, fatigue, and vitality. The analysis included 81 separate trials involving over 7,000 participants. Each trial consisted of at least two exercise sessions per week, with control groups either remaining sedentary or participating in low-level activities like stretching.

Here’s what they found:

• Increased energy: Regular exercise leads to small but meaningful improvements in energy levels.
• Reduced fatigue: Exercise significantly decreases feelings of fatigue.
• Boosted vitality: Participants reported moderate increases in their overall sense of vitality – better than results achieved through medications or cognitive behavioural therapy.

These exercise benefits were enhanced by:

• Higher-intensity exercise (this improved all outcomes).
• Combining resistance and aerobic exercises (this optimised energy and vitality).
• Longer exercise sessions and sustained programmes (these reduced fatigue).

Although it may seem counter-intuitive, exercise helps reduce fatigue by improving hormonal regulation and enhancing sleep quality. This combination ensures you feel more energised during the day.

Physical health benefits of exercise

Regular exercise offers a wealth of physical benefits. Let’s take a look at a few.

Lower your risk of heart attack and stroke

Heart disease and stroke are two of the most dangerous health conditions, but the benefits of exercise can significantly lower your risk. According to the CDC exercise recommendations, adults should aim for:

• 150 minutes of moderate aerobic exercise per week, or
• 75 minutes of vigorous aerobic exercise per week.

Regular exercise can reduce the risk of heart attack by up to 40% and stroke by 50%. Additionally, it lowers blood pressure, improves cholesterol levels, and reduces your resting heart rate, all of which promote cardiovascular health.

Reduce chronic pain and stiffness

If you experience chronic pain or stiffness, exercise can be an effective remedy. By increasing blood flow to your joints and releasing endorphins, exercise can alleviate discomfort from conditions like arthritis, back pain, or muscle strains. Improved range of motion and flexibility are additional short-term benefits of exercise for those suffering from stiffness.

Help you breathe easier

For those with asthma or other respiratory issues, regular exercise offers significant advantages. By improving lung function, increasing endurance, and reducing stress, exercise can help prevent asthma attacks and enhance breathing. Long-term commitment to exercise can make breathing more effortless and enhance overall quality of life.

Mental health benefits of exercise

Provide a sense of well-being and happiness

The mental benefits of exercise are profound. Regular workouts release endorphins, which create feelings of happiness and reduce stress. Exercise also boosts serotonin levels in the brain, enhancing mood and alleviating symptoms of depression and anxiety.

Additionally, exercise can:

• Improve self-confidence.
• Enhance cognitive function.
• Promote better sleep quality.
• Foster social connections through group activities or sports.

With these benefits, it’s no surprise that mental health professionals often recommend regular exercise for emotional well-being.

Short-term and long-term benefits of exercise

Short-term benefits of exercise

• Boosted mood and reduced stress.
• Immediate improvements in energy levels.
• Enhanced focus and mental clarity.
• Reduced stiffness and improved flexibility.

Long-term benefits of exercise

• Lower risk of chronic diseases, including heart disease, diabetes, and some cancers.
• Improved muscle tone and joint health.
• Sustained weight management.
• Enhanced longevity and quality of life.

By focusing on both the immediate and lasting exercise benefits, you can create a healthier and more fulfilling lifestyle.

What about exercise and weight loss?

Exercise is often associated with weight loss, but science shows that it’s only one piece of the puzzle. At our lab, we focus on ensuring clients achieve an overall active lifestyle, complemented by weight training to preserve and build muscle mass. However, significant weight loss primarily relies on caloric restriction rather than counting the calories burned during exercise.

That said, exercise offers numerous benefits beyond weight loss, making it a key part of a healthy lifestyle. By focusing on the benefits of exercise, you’ll find motivation to stay active, even beyond achieving weight goals.

Conclusion

The benefits of exercise are undeniable. Whether you’re aiming to improve mental health, reduce the risk of disease, or simply feel better day-to-day, regular physical activity offers unparalleled advantages. From the short-term benefits of exercise, such as boosting mood and energy, to the long-term benefits, like enhanced vitality and reduced chronic disease risk, there’s no reason not to incorporate movement into your daily routine.

Ready to experience the life-changing benefits of exercise? Start small—20 to 30 minutes a day—and build from there. Whether it’s a brisk walk, weight training, or yoga, every step you take brings you closer to a healthier, happier you. To find out more about how My Vital Metrics can bring you closer to achieving your exercise goals, reach out for a free fitness and nutrition consultation at MVM today.

The T-Score doesn’t compare you to your own age group, but rather compares your bone density to what is considered ‘peak’ bone density – which is usually a healthy 30 year old, or thereabouts. Once again it is expressed in standard deviations, so a positive value means you have more dense bones than average, and a negative value means your bones are less dense than average.

DEXA Scan Results: Understanding Your Body Composition

Choosing the Right Body Composition Goal for You

It’s the age-old fitness question: can you build muscle and lose fat at the same time?

Here at My Vital Metrics, one of the first things we will do when you come in for a fitness assessment depending on your results, will be to help you set a primary goal. For body composition clients this will often mean choosing between fat loss and muscle gain.

So, does that actually mean you can’t build muscle and lose weight simultaneously? Classic body-building would say so, claiming that you need to ‘eat big to get big’. Overall, it’s technically true that you need to be in a caloric surplus to gain muscle, and you most definitely need to be in a caloric deficit to lose fat – so that makes these two goals incompatible, right?

As always, body recomposition is a little more complex than that, so let’s break it down and see whether this Holy Grail of body recomposition is possible.

Before we dive into the topic of fat loss vs. muscle gain, we should point out that there are many other worthwhile health and fitness goals: movement quality; injury prevention; posture; sporting performance, and many more. With that in mind, let’s start with the phenomenon that causes the most confusion on the issue of whether you can gain muscle and lose fat at the same time: “newbie gains”.

Building Muscle and Losing Fat: “Newbie Gains”

There’s plenty of good evidence in the literature that for new lifters, gaining muscle and losing fat at the same time is absolutely possible. There is some debate however over the specific mechanism of action by which this is achieved. One theory is that because they are not yet efficient at converting food into muscle, the metabolic adaptations happening for the first time require a lot of extra energy from the body, and so someone burns extra fat.

However, most newbie lifter plans (if taking a newbie in an untrained state, and assuming they want to burn fat also) would usually put them into a caloric deficit, and so really the question is ‘how does a newbie gain muscle so well, when in a deficit?’ We’ll hold this question for a moment while we go through the science.

The Science of Losing Fat: A Calorie Deficit

The most important thing to remember is that you need to be in a caloric deficit to lose fat. This means you need to be eating less than your body burns to keep itself alive and you moving around. Everything you do, from breathing, or your heart beating, to brain function, even to the act of eating and processing food will expend calories. And, of course, your activity: moving around, and exercise is all part of that. How much less you need to be eating depends on a lot of factors.

The best way to establish an accurate sense of your caloric needs is through an RMR test. This will tell you how many calories you need each day to keep yourself alive (this is your Resting Metabolic Rate or Basal Metabolic Rate), and how many calories your Total Daily Energy Expenditure (TDEE) is. This is the number of calories you could eat to be in perfect energy balance – neither gaining nor losing weight. From there, we can work out how many calories you need to eat to lose fat. This will be somewhere between your TDEE and your RMR.

We have to remember, however, that being in a caloric deficit isn’t a magical switch to start burning fat alone – the body will make economies to try to balance its energy from all its systems and all its tissues. Without other stimuli to the body, the body is just as likely (more likely actually) to rid you of muscle which you aren’t using, because muscle is costly tissue to maintain. It may also leach from bones, and temporarily reduce expenditure in many other ways to balance its energy needs. This whole process: the process of removing tissue to use for energy is called ‘catabolism’, and someone in this state can be referred to as ‘catabolic’. So a deficit will (without other stimuli) lose us muscle – that’s the key thing to remember as we move to talk about how a caloric surplus works.

The Science of Gaining Muscle: A Calorie Surplus

Contrary to the above, to gain muscle you need to be in a caloric surplus. This means you need to be eating more calories than your TDEE. Of course, just eating more than you need is not sufficient to gain muscle. You need to send stimuli to the body to tell it where to put those extra calories. Left to its own devices, and without this stimulus, the body will add to systems as it sees fit. This might mean it upregulates (turns up the dial on) the immune system, hair and nail growth, mental energy, dopamine responses, and of course, there’s inevitably going to be some of those calories which go to fat stores, energy stored for future use. To predispose you to gaining muscle you have to have a good-quality hypertrophy or strength training plan. This creates the stimuli to the body to divert some of these excess calories over to muscle growth. It is a signal to say to the body ‘Hey, I am lifting big, so you’d better make these muscles stronger and bigger or I might injure myself or be unable to do what I need to do to get food and keep myself alive’. Of course, we know that your lifting is not directly connected to your survival, but from an evolutionary point of view, that’s how the body sees it. Likewise with the deficit though, a surplus will add to all tissues. If you weight-train, then some of that excess will go to muscle, and bone, as well as strengthening tendons and ligaments. Inevitably, however, some fat will also be gained, so sizing up the amount of the surplus is important. In classic bodybuilding methods, a surplus is the ‘bulking’ phase of the diet, and they accept that fat will be gained during the process, but they value muscle more so they take this hit, with the expectation that they’ll lose the fat later down the line. This whole process – the adding of energy to muscles, bones and other tissues is called ‘anabolism’ – so someone in this state is referred to as ‘anabolic’. You may recognise the term from ‘anabolic steroid’ – which are basically hormones which increase the body’s anabolism.

Energy Balance Throughout the Day

We haven’t discussed so far the important role of protein in the above processes. Suffice it to say that protein is critical as it contains all the building blocks that allow us to put on or keep muscle. The protein content of a diet is incredibly important in that it facilitates greater anabolism, and prevents excess muscle catabolism.

So from the above, it seems pretty clear – you are either anabolic or catabolic at any given point in time. Case closed, you can only pursue one goal at a time – right? Not quite.

So, the premise is correct: you can only be in either an anabolic state or a catabolic state at any one time, however, which state you are in will vary throughout the day. Just woke up and started moving about, before breakfast? You’re catabolic. Had a nice big breakfast, you’re now anabolic for a while. Just finished your workout? You’re very catabolic. Downed a protein shake? You’re anabolic again.

So you aren’t permanently in one state or another, but rather it varies throughout the day, and by playing with this, and timing your meals (and protein especially) appropriately, we might be able to get to this goal.

How to Fuel your Body to Build Muscle and Lose Fat

If you want to gain muscle and lose fat concurrently, you need to make sure that you’re in a surplus (eating more than you need) for some of your day, but also be in a deficit (eating less than you need) for the other parts.

When you are in each state will need to depend on your workouts. Remember, the major stimulus you can put into the system is a solid weight-training workout. So it is immediately after this, and for a few hours that you’ll want to be in a surplus so that the body diverts all those excess resources over to refilling muscle glycogen, and repairing muscle tissue. For the rest of the time you’ll want to be in a deficit.

Overall, the energy balance does need to be a deficit. If the balance at the end of the day or week is positive calories, then you will not be able to lose any fat.

Have we found the Holy Grail of body recomposition?

In short, both of these can happen at the same time, but it’s not the easiest balance to maintain for many people. Remember also that by aiming for both, you are compromising on maximal progress on each. We are all for this approach, however. It gets people eating a good amount of calories that is sustainable and should feel pretty filling, and good, and it allows people to pursue an overall better physique and get healthier on multiple measures of fitness simultaneously. We’d overall rather see this approach which may take a year or maybe even two, rather than the dramatic bulk-cut cycles we sometimes see.

That said, this approach may have diminishing returns the further up the bell curve you are in terms of existing muscle mass. In other words, if you are a person who is already carrying a lot of muscle from many years of training, managing to grow more muscle while in a deficit is increasingly unlikely the more muscle you already have. Going back to our ‘newbie gains’ discussion, this is probably why new lifters are so much better able to add muscle when in a deficit. If they are carrying much less muscle than we are evolutionarily capable of, the body is far more likely to add muscle as a priority given the right stimulus.

To find out more about how you can meet your body recomposition goals, book a free fitness consultation at My Vital Metrics today!

One of the most common questions we get is what kind of diet our customers should follow. Of the various diet plans and options out there, the one that comes up the most is the keto diet, or very low carbohydrate diet. Below we look at what the keto diet is; what a keto diet looks like on a day to day basis, and whether someone should consider it as a way to lose fat or recompose. We will also cover issues of performance and health.

What is the keto diet?

The keto diet is a low-carb, high-fat eating plan that has first gained some notoriety in the 1970s with ‘Dr Atkins’ Diet Revolution’ book. It caused such a stir at the time because Dr Atkins claimed that a person could eat any amount of food and still lose fat on the keto diet. These claims were later retracted, and keto hit the news again in the 1990s with the reissue of ‘Dr Atkins’ NEW Diet Revolution. The diet is based on the premise that carbohydrates (including sugars and grains) stimulate the secretion of insulin, a key hormone that helps the body store fat amongst other things. When your body runs out of carbs storage, you are forced to use body fat as the primary fuel source. When burning fat, in the absence of any stored carbohydrate, the body produces by-products of the fat-burning process called ‘ketone bodies’. Therefore, because this style of eating is intended to create ketones, it is referred to a keto-genic (genic is just Greek for ‘giving birth to’ – thus ‘gene’, ‘genesis’ etc). The key thing with keto is that you try to eliminate carbohydrates altogether. In reality this isn’t possible, but many keto advocates will attempt to keep carbs below 20g.

Is Keto the same as Low-Carb?

Keto is the very extreme form of low carb diet, but the two forms of diet are not the same. Low carbohydrate diets range all the way from around 40% of your daily calories coming from carbohydrates, right down to as little as possible – which is theoretically ‘keto’. In most low carbohydrate diets the focus is on measurement and control of carbs. On keto the key measurement that’s performed is daily (or more frequent) urinalysis or blood test or (more recently) breath testing to see if the body is producing ketones. It works on the assumption that carbs have been all but eliminated from the diet, so they don’t need to be measured per se.

What does a keto diet look like on a day to day basis?

On a day-to-day level, keto adherents will be eating a lot of meat, and (hopefully) green leafy vegetables and broccoli. They may be adding oil to all their food and may be having nut butters and other high-fat snacks (but without the bread). The food will be heavy and high on protein and fats (being the other two macronutrients). Breakfasts may be hot. Eggs, bacon, sausages are all fine – but hold the toast and beans. In restaurants they may steer away from Asian foods which tend to have a lot of hidden sugars and will likely go for the plainest meatiest dish on the menu. They’ll be asking their waiter to remove chips, potato (sweet or otherwise), bread, rice, noodles. With the availability of very low carb food substitutes, at home they may be having noodles or rice made of Konjac flour, or heart of palm but for some even this may be too many carbs. Desserts may just not exist at all, or some adherents may have one small square of 90% cark chocolate. I once knew someone who would prepare a dessert of 0-calorie jelly and double cream. All in all, it’s pretty restrictive.

In what circumstances might the keto diet be helpful?

A keto diet may help to reduce insulin resistance and increase insulin sensitivity. With the aim being to keep insulin low, this may have some beneficial effects on this and blood sugars in general. I may also be helpful for adherence in the specific case that all the foods that a person really likes are these heavy fatty, carb-less foods. There are of course some key medical areas in which a keto diet may be helpful. The diet was originally developed as a treatment for some forms of epilepsy. Ketones are a unique energy source in that they can cross the blood-brain barrier, and so can be used to fuel the brain. There is an evolutionary theory that the body developed ketones in order to serve this very purpose in circumstances of low availability of plant foods. In general people who are well adapted to the keto diet, often praise it for the smooth even mental energy and focus it gives them. By not being subject to the vagaries of high and low blood sugar, ketone advocates will say that they work and think better on keto. The nature of the food will also keep you fuller for longer, so if you find yourself feeling hungry every couple of hours, maybe keto could show you what long-term satiety feels like.

The cons of the keto diet

The first and most obvious downside of the keto diet is how restrictive it is. In a restaurant it will be near impossible to find a meal that doesn’t need to be modified in order to be somewhat compliant. And even with modifications, the threat of hidden sugars is ever present.

The second is the the days referred to as ‘keto flu’. In the first few days of adopting the diet, the body is having to adapt to an energy source it is not accustomed to. It may not be efficient at this and may in effect be ‘waiting around’ for more carbohydrates to enter the system. During this time the person feels especially lethargic, low motivation, low energy, and often headaches and other symptoms may emerge. Once the person starts to keto-adapt these symptoms will usually subside.

Lastly, keto is a huge problem because it is a bit ‘all or nothing’. If you have a single big carb meal, this will certainly be sufficient to kick you out of ketogenesis and may even refill some lost glycogen. If this happens that means that it may even mean you’ve lost ‘keto’ status for another 5 days, and another period of keto-flu is ahead of you to get back into it. The fact that the diet can’t really withstand even small lapses in adherence is a big problem, psychologically. If someone has a carb meal, they often will throw the diet to the wind and carb up while they can, and ‘restart on Monday’. This approach is hugely problematic and ultimately defeating for any consistent or concerted fat loss effort.

Is the keto diet good for fat loss?

The ketogenic diet has been proven to be an effective weight loss tool in clinical trials, but the diet must be properly followed to result in weight loss. The key thing to note however is that, as anyone who has followed keto can tell you, in the first week after the keto flu, you lose sometimes 2-3kg straight off the bat. This can be very encouraging, but we also know that this weight loss is pure water. Every molecule of glycogen (stored carbohydrate) in the muscles and in your liver, attaches to two molecules of water. When you deplete your glycogen, the water is released, leading to the 2-3kg of weight loss. In DEXA terms, this will mean an instant loss of 2-3kg of lean mass. So, it’s important to keep consistent between scans. If you take your baseline scan already in keto, you will need to take your update scans also in keto to get a like-for-like comparison.

In longer term studies however, the results of keto dieters did not exceed that of other forms of diet when equated for calorie deficit. Keto is therefore not a magic bullet of any kind for fat loss. Furthermore, the extreme restriction of lifestyle that accompanies keto may make adherence to and consistency on the diet plan very difficult.

The final verdict: Should you follow the keto diet?

There may be a limited number of circumstances in which the keto diet may have some uses, but in general we don’t like how all-encompassing it needs to be to be effective. Ultimately it will be the number of calories you consume on the plan that is the determinant of the amount of fat you can lose. If we ever choose to deploy a keto plan (and it is unlikely we would prescribe something so restrictive) it would be for a very particular purpose, and probably be for a short amount of time.

As we are all about sustainable ways of eating and long-term eating for health rather than diets, we don’t really like how many adjustments people have to make to their lives in order to follow this plan.

That said, if someone is keen to go on keto, we will of course support them, but we will still come back to the fundamentals of a sustainable calorie deficit while eating a wide-ranging nutrient dense and interesting diet. And time and time again, we have the DEXA results to show that this approach works. Every time.

Weights vs. Cardio: Which should I be doing if my aim is to ‘recompose’?

The most common question I get when talking about exercises for recomposition is whether weights or cardio will be better for the client’s goals. The answer to this is going to depend very much on each client’s needs and goals, but there are a couple of universals. Some weight training as part of any general recomposition plan is a non-negotiable part of the plan. Cardio is a bit more particular, and I would only recommend it in certain circumstances. Lets take a look at the two forms of training, what they do and how they should be used.

What do we mean by body recomposition?

Recomposition is a process of changing your body’s composition – what it is made of. 80kg at 25% body fat for a man, is a very different picture to the same 80kg at 12%. Generally speaking, composition goals tend to be about getting more muscle and less fat into the same or similar weight footprint.

A comprehensive fitness program should consist of a combination of different types of training to maximize results, and build an overall level of ability in each area. This usually incorporates a combination of strength and conditioning, metabolic training, stretching, and functional training. This is to build an overall fitness program and optimize the body for all aspects of life. Of these though, functional training and stretching are more enablers in a recomposition programme, while the strength and conditioning and the metabolic training do all the heavy lifting (pun intended) with the actual recomposition.

When to use weights in recomposition

Weight training is often not the first thing most people think of when they think of exercising for a fat loss programme. Think of the countless images in ads and movies of people running or skipping or rowing. Weight training is more commonly associated with a goal to build strength and muscle mass. However, when considering the value of weights vs cardio for a recomposition programme, lifting weights has an essential function: to preserve the muscle mass we already have.

We will talk diet in more detail below, but in general terms, a recomposition diet will involve a calorie deficit of some form. That means eating fewer calories than your body is expending. In this context, we must limit out expectations of how much new muscle the body is going to be able to build. With the exception of people completely new to weight training, most people will not be able to gain a lot of mass while in a deficit.

So why do it? Well, muscle is incredibly expensive for the body to maintain. In other words it takes a relatively large number of calories to maintain your muscle mass when compared to maintaining fat or bone. The outcome of this, is that when your body is in a caloric deficit, the body will need to make cuts, and as a metabolically expensive tissue, the body will, if left to its own devices cut muscle first. It will do this unless there is some reason not to. The body is smart, in that it will not cut tissues which are actively being used. If you are sending signals to the body (by lifting weights) telling the body that you are using the muscles, the body will preserve those muscles which are being used. If you don’t send those signals, then the body will reduce tissue size in all tissues, but it will start with those tissues which will spare it the most calories, and that’s your muscles.

But I didn’t want all that muscle anyway!

Actually, you really do. Unless you are a professional sportsperson in some very specific sports, more muscle is almost always a good thing. We will all undergo some muscle loss eventually in our lives. The process accelerates in our 40s and 50s, and so I always advise clients to pack on as much muscle as they can before these ages, and then just work to preserve it after this time. With a good level of muscle mass, preserved through regular weight training, we can have full, productive, and quality lives into our 70s and beyond. Planned for well, we may never reach a time when we can’t get out of a chair by ourselves. But coming back to recomposition, more muscle mass, means a higher metabolic rate, which means we can eat more, while still losing weight. If you lose a lot of muscle, it will affect your metabolic rate, and you will have to eat an ever decreasing number of calories to maintain losing weight (to a point).

The upshot of all of this, is that weight training is an absolute essential parto f any recomposition programme, and separate to that, I would say is an absolute essential part of anyone’s fitness routine.

When to use cardio in body recomposition

Cardio is a type of training that involves working at a moderate-to-high intensity for a period of time. It is a form of training that can be used to help increase the body’s ability to use oxygen while improving overall health and fitness. A well trained cardiovascular system will mean you are able to climb stairs, run for the bus, or just generally go about your day without getting out of breath. Cardiovascular health is an absolute must for everyone. A healthy cardiovascular system is a huge mitigating factor in a host of health risks. To train the cardiovascular system well you need to do a couple of different types of training: long slow distance type at a low level heart rate (zone 2) will improve your aerobic base, while HIIT training will improve your anaerobic threshold. These types of training do take time, and are worth doing for their own sake. When it comes to recomposition however, the story is not as clear as all that.

We used to think that if you spent 1 hour on a given day running, and burned 800kcal in that run, that this would automatically put you into an 800kcal deficit, and that the body would take the excess from your fat stores. Cardio was therefore all about creating a deficit through greater activity. Unfortunately the most recent science on the matter indicates that this is not what happens. Instead, the body seems to want to stick within its own limited number of calories that it likes to consume, and, instead of burning new calories, will make cuts to other parts of expenditure in order to accommodate the extra calories required for the exercise. An 800kcal run, which is not replenished with food, may for example cause the body to cut the budget of the immune system by 300kcal, brain function 200kcal, and dopamine production of 100kcal, new calories burned then would be only 200kcal, and the rest would be calories redirected from other systems.

So when it comes to burning through calories, cardio is not anywhere near as efficient as we used to think. The body is too smart a manager of resources to always dip into storage when energy is low. So the real question of the article is really not a toss-up between cardio and weights, but actually a toss-up between creating a calroie deficit through cardio, or creating it through food.

I have limited time – what should I focus on?

It seems pretty clear from above, that as far as time-efficient ways to engage in a recomposition programme goes, weights is a non-negotiable, while cardio seems optional. The creation of a calorie deficit through cardio is incredibly inefficient, and most especially is time-inefficient. If we choose to instead take a calorie controlled way of eating, and create out calorie deficit through that, then cardio ‘exercise’ becomes an optional, and for some people I would not even suggest that they do any dedicated cardio ‘exercise’. I’m using ‘exercise’ here to indicate cardiovascular work which is just going through the motions in order to burn more calories. This is separate from cardiovascular ‘training’ which is specific and targeted work to train and get the cardiovascular system stronger.

Conclusion

If you thought I would end this article with an on-the-fence result saying that “Weight training and cardio are both important parts of any recomposition program” you’re about to be disappointed. In my mind weight training to preserve muscle whilst eating to a calorie deficit is the best and most sure-fire way to achieve success in a recomposition programme. If you want to simultaneously throw in a HIIT session to keep your heart in tip-top shape, then that’s great, and I’d recommend it, but don’t do it thinking you’re burning through new calories. One final thing I haven’t mentioned is NEAT – Non-Exercise Activity Thermogenesis. This is the general level of activity you have during the day outside of your workouts. It is getting up and moving around between zoom calls, walking to the shops or the station and so on. This type of activity is really important to keep high for general health and will be a great plus to your recomposition programme. As ever if you’d like to discuss this and more, and get specific in how to recomp yourself, get in touch and book a DEXA.

What are the primary factors that influence bone health? 

The non-modifiable factors that affect bone health are family history, age, sex and ethnicity.  The modifiable factors are ‘mechanical load’ (exercise), sleep, diet and smoking. 

Exercising into middle age and older age is a powerful intervention to maintain bone mass.

Exercise in childhood and adolescents seems to provide protection to bone health for longer periods over the life cycle. 

The positive effects of exercise on bone come from multi-directional movement and high impact exercises. 

From a nutrition point of view, if you are insufficient or deficient in circulating levels of Vitamin D in the blood then it is important to get sufficient. 

Supplementation may play a role in this process because it is difficult to attain Vitamin D from dietary means. If you want to investigate Vitamin D levels further then speak with your GP. 

Adequate intake of calcium plays a role in supporting bone health: 

19 – 64 years of age – 700mg a day. 

11 – 18 years of age – 800mg in girls and 1000mg in boys. 

Other nutrients important to support bone health through the life cycle are: 

• Magnesium
• Vitamin K2
• Vitamin C

Some great example of whole food sources of these are below: 

Non-Dairy Sources

One thing we know is that bone does not like chronic low levels of energy availability.  

Energy availability is the dietary energy left over to the body after the energy expended from exercise has been accounted for. 

That means if you are exercising very frequently and not meeting energy needs from a dietary intake point of view (calories) be very careful as this may affect bone health over time. 

It is always best to speak with your GP first. If you are engaging in a lot of exercise, especially endurance exercise it may be worth speaking with a Sports & Exercise Registered Nutritionist (SENr) as well. 

How do I assess the status of my bones?

Popping in for a 3 minute DEXA scan with us will allow you to assess bone mineral density.  

Please be aware that we do not offer the service as a diagnostic tool, we simply present your bone mineral density via two important scores. 

A Z-score compares your bone density to the average bone density of people of your own gender and age.

A T-score represents how close you are to the average peak bone density. Meaning how do you differ from the bone mass of an average healthy 30-year-old adult.

Below are some additional resources that might allow you to read further:

Resources: 

Bone Health during the Menopause Transition and Beyond:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6226267/pdf/nihms-1506835.pdf

Nutrition and bone health in women after the menopause:

https://journals.sagepub.com/doi/pdf/10.2217/WHE.14.40 

Nutrition & Athlete Bone Health

https://link.springer.com/content/pdf/10.1007/s40279-019-01161-2.pdf