Body composition in performance testing: stop ignoring it

Body composition is highly important in athletic performance and performance testing. Although often ignored, body composition goes beyond weight and body fat. In lactate testing for instance, concentrations are expressed in mmol lactate per liter (mmol/L). But do you know which “liter” it is about? Let’s dive into the key elements of athletic body composition that determine performance and affect performance testing.

Body Fat Calculator

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Body composition and athletic performance

Body composition is the quantification of different body components, like percentage of fat, bone, muscle and water. Body composition goes beyond looking at body weight or BMI (Body Mass Index).

Body composition is an important component of fitness, since it affects both health and performance. The most straightforward example of why body composition is important in athletic performance is when looking at weight-bearing sports like running or sports that require athletes to overcome altitude, like mountaineering and cycling. But there are more ways in which body composition affects performance, which we’ll cover in this article.

Test body composition

Since body composition affects athletic performance, athletes engaging in performance testing should also test their body composition.

In fact, body composition directly affects athletic performance metrics like VO2max, anaerobic threshold (or FTP) and VLamax, which we’ll dive deeper into in a minute.

INSCYD allows you to test body composition in sports and takes body composition into account when showing the metabolic profile.

Body fat percentage

The most well-known component of body composition is body fat percentage. Athletes may also refer to lean body mass, which is total body mass minus body fat mass.

There are many ways to measure or estimate body fat. For instance by using a body fat scale that estimates body composition based on bioelectrical impedance. Or by calculating body fat with a skinfold test. But in practice you can get a good estimate of body fat without using any measurements.

Body fat calculator without measurements

Calculate your body fat without calipers or body fat scales. Use this body fat calculator:

Body Fat Calculator

Weight (kg): Height (cm):

Gender: Male Female

Neck Circumference (cm): Waist Circumference (cm):

Results:

Body Fat Calculator

Weight (kg): Height (cm): Neck Circumference (cm): Waist Circumference (cm):

Gender:

Male

Female

Hip Circumference (cm):

Results:

Measure the neck circumference just underneath the Adam’s apple. Measure the waist around the navel (men) or narrowest part of the abdomen (women). Measure the hips at the widest part of the buttocks or hip.

The optimal body fat for performance

The optimal body fat percentage for athletes is 6-13% for men and 14-20% for women, according to the American Council on Exercise (ACE). However, the ideal body fat percentage differs per individual and less is not per se better.

Typical % for	Men	Women
Essential Fat	2-5%	10-13%
Athletes	6-13%	14-20%
Fitness	14-17%	21-24%
Average	18-24%	25-31%
Obese	25%+	32%+

Body fat ranges across athletes and non-athletes. Source: American Council on Exercise, ACE.

The ideal body fat percentage probably differs per sport. This scientific research looked at the body fat percentage of 826 American elite athletes. When we combine this data with data from the American Council on Exercise, a review article on the Current Status of Body Composition Assessment in Sport and the book Sport Nutrition by Jeukendrup, we can create normative data for body fat percentages per sport:

Sport	Male	Female	Sport	Male	Female
Baseball	12-15%	12-18%	Rowing	6-14%	12-18%
Basketball	6-12%	20-27%	Shot Putters	16-20%	20-28%
Body building	5-8%	10-15%	Skiing (X country)	7-12%	16-22%
Cycling	5-15%	15-20%	Sprinters	8-10%	12-20%
American Football (Backs)	9-12%	No data	Soccer	6-18%	13-18%
American Football (Linemen)	15-19%	No data	Swimming	9-12%	14-24%
Gymnastics	5-12%	10-16%	Tennis	8-18%	16-24%
High/long Jumpers	7-12%	10-18%	Triathlon	5-12%	10-15%
Ice/field Hockey	8-15%	12-18%	Volleyball	11-14%	16-25%
Marathon running	5-11%	10-15%	Weightlifters	9-16%	No data
Racquetball	8-13%	15-22%	Wrestlers	5-16%	No data

Body composition in lactate testing

When expressing VO2max in oxygen uptake per kg bodyweight, or FTP in watts per kg bodyweight, you immediately understand the importance of body composition. However, when you take a blood lactate sample and the analyzer shows: 4 mmol/l, do you know which “liter” it is talking about? Is it liters body content? Liters of blood? Let’s find out.

In lactate testing, the mmol per liter is showing you a concentration of lactate. As always when looking at a concentration, both the solute and the solvent are important.

Imagine your smallest athlete riding a stationary bike at 200 watts. The leg muscles produce lactate – and you measure the lactate concentration with a blood lactate analyzer: 4 mmol/l.

Now imagine we could put the exact same leg muscles into another – in this case larger athlete. We then ask the athlete to ride at the exact same intensity. Results? You’ll see a blood lactate concentration below 4 mmol/l. Simply because the athlete is larger and the lactate will dilute in a larger space.

In other words: the exact same muscles produce the exact same amount of lactate, but you will measure a (totally) different blood lactate concentration.

This is not only the case when comparing lactate concentrations between individuals with a different body composition, but also when comparing lactate results within an individual who is changing body composition (e.g. losing weight, increasing muscle mass etc.)!

Conclusion: if you’re working with lactate measurements and you want to compare results over time (within an individual) or between individuals, you need to know more about body composition. Specifically, you want to know more about the lactate dilution space.

What determines lactate dilution space

To make all this information actionable, we need to know what determines lactate dilution space and how to measure it.

Since lactate is water-soluble, it can dilute/exist in parts of the body that contain water (like the blood where it often gets measured).

The next question is: how to measure body water content and convert it into lactate dilution space.

How to measure lactate dilution space

Now we know lactate exists in parts of the body that contain water, we want to understand something about the amount of water in an individual body.

Although there are measurement tools that measure body water content, it’s often easier to measure or estimate body fat. Some athletes may even have a body fat scale at home. To go from body fat to a fairly accurate estimation of body water is easy, although you need to take gender into account.

INSCYD uses different default values for lactate distribution space for males and female.

Body composition difference between male and female

It goes without saying that the body composition of men and women are different. To give one example: on average, women have a higher body fat percentage than men. This decreases lactate dilution space, since lactate does not dilute in fat.

Knowing this, you should think about the use of conventional lactate profile concepts such as D-Max, 4 mmol/l etc. in female athletes. All those concepts have been developed and validated only in males.

INSCYD is probably the only software for performance analysis out there which takes gender into account. We hope this is the trigger for female cyclists around the world to start questioning their current methods of performance analysis. We’re happy to say this was one of the reasons why professional women’s cycling team CANYON//SRAM partnered with INSCYD.

INSCYD Coach about: Body composition

“As a professional triathlete, power to weight ratio was drilled into my head. I wanted to be lighter so I trained harder. I ate less. I got injured. With INSCYD, coaches can do so much better to support the health of their athletes and ultimately their performance. We can train with our unique physiology.

Understanding body composition and lactate concentration is an important part of exercise prescription not only because we can better identify the intensity of training intervals but because we can identify how long (or short!) it will take the athlete to recover. This means more quality work that gets you to your goals – body composition change, personal bests or just having more fun on epic adventures.

INSCYD has changed the game for athletes and coaches. If you want to save time and effort to play to your best it only makes sense to train with your body. Take out guess work. You are not the same as everyone else.”

Additional body composition information

The INSCYD software will share more body composition information in the report. To name a few:

Available glycogen – depending on your sport
Active muscle mass – depending on your sport
Body Mass Index (BMI)

If you are eager to learn more about scheduling a Free Demo Call on your language to explore more.

Body composition and VO2max

Your VO2max tells you how fast your muscles can use oxygen in milliliters per minute. Often VO2max values are relative to body weight: ml/min/kg. As a result, weight affects VO2max and weight loss helps to increase VO2max.

If an athlete is twice as heavy, he/she needs to transport twice as much oxygen to the muscles to get the same relative VO2max. If the heavy athlete would have twice as much muscle mass, then this would make sense, because that additional muscle mass needs oxygen.

However, often additional weight is a mix of additional muscle mass, fat mass, bone mass etc. That’s why some researchers suggest relative VO2max should be based on lean body mass, not total body mass. After all, fat doesn’t need oxygen.

This scientific suggestion makes clear that it’s important to take body composition (beyond weight) into account when looking at VO2max numbers, regardless of whether you’re using absolute or relative VO2max.

One final note on body composition and VO2max. Although additional fat decreases the relative VO2max from a calculation point of view, science shows that: “fatness and excess body weight do not necessarily imply a reduced ability to maximally consume oxygen”.

Understanding VO2max in relation to total body weight offers valuable insights, but to truly optimize performance strategies, considering VO2max relative to lean body mass is crucial. Lean body mass, essentially the weight of one’s body minus the fat, is metabolically active and directly involved in the production of energy during exercise. This distinction is vital because it acknowledges that not all body weight contributes equally to oxygen utilization and energy production.

By focusing on VO2max values adjusted for lean body mass, coaches and athletes can gain a more accurate measure of potential for improving VO2max per kg of body weight. This approach allows for more personalized training programs that can precisely target improvements in aerobic capacity, ensuring that athletes are not merely losing weight, but enhancing their true performance potential.

INSCYD considers both total and lean body mass in performance testing, offering a more nuanced understanding of an athlete’s aerobic capabilities and how to effectively enhance them.

Body composition and FTP

We already talked about the effect of body composition on lactate concentration and therefore lactate testing. So when assessing the lactate threshold or FTP, you should take body composition (beyond weight) into account.

Similar to VO2max, the Functional Threshold Power (FTP) is often divided by bodyweight into a weight-to-power ratio (watt/kg). The idea is that the higher the bodyweight, the higher the FTP should be to perform at a similar level. This makes sense both from a weight-carrying perspective when climbing and from an aerodynamic perspective (although to a lesser extent).

Again we see that body composition is an important factor when interpreting FTP values. Not only because body weight directly affects FTP in watts/kg, but also because it matters where this mass is coming from. Not all additional weight is bad.

As you can imagine, mure muscle mass could actually lead to a better performance, while a higher fat percentage may not. Either way, knowing your current body composition and tracking it over time is important in analyzing performance and performance testing results.

The Ultimate Solution for Precision Performance Analysis

Understanding the intricate details of body composition and its impact on performance is not just beneficial; it’s essential. Traditional methods of assessing performance often overlook the critical role of body composition, leading to generalized training programs that may not cater to an athlete’s unique physiological needs.

This is where INSCYD steps in, offering a groundbreaking approach to performance analysis that integrates body composition into the equation for truly personalized training strategies.

Comprehensive Analysis: INSCYD goes beyond traditional metrics like VO2max and FTP, incorporating body composition to provide a holistic view of an athlete’s performance capabilities.
Gender-Specific Insights: Recognizing the differences in body composition between males and females, INSCYD offers customized analysis, ensuring accurate and effective performance strategies for all athletes.
Elevate Performance: By integrating body composition into performance analysis, INSCYD helps coaches and labs optimize training, improve recovery, and achieve their personal bests.

Don’t let traditional performance testing methods limit your potential. Embrace the future of sports science with INSCYD’s advanced analytics. Whether you’re a coach looking to elevate your athletes’ performance or a lab seeking to offer cutting-edge analysis, INSCYD is your partner in achieving excellence.

Book Your Free INSCYD Demo Today and Experience the Revolution in Performance Analysis. See firsthand how INSCYD’s precision analytics can transform your approach to training and unlock the full potential of your athletes.

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