Fat Percentages and Endurance Athletes.

This is a topic that needs to be approached with caution. The concern arises from the delicate balance between weight management and performance optimization. On one hand, an athlete may become excessively fixated on maintaining a certain weight, while on the other hand, careful monitoring of fat measurements can prevent the athlete from experiencing negative consequences of excessive weight loss or gain.

Striking the right body fat percentage for athletes is influenced by factors such as their specific sport, age, and gender. Generally, athletes tend to have lower body fat percentages compared to non-athletes, as excess body fat can impede performance in many sports. Cyclists, in particular, are acutely aware of the impact of weight on their performance, as one of the crucial metrics is the watts/kg ratio. An example of a test commonly used in cycling is the FTP (Functional Threshold Power) test, which involves evaluating a cyclist’s performance over a 20-minute period.

By closely monitoring body fat and weight, athletes can ensure they maintain an optimal balance. Excessive weight loss can lead to the development of RED-S (Relative Energy Deficiency in Sport), which can have detrimental effects on overall health and performance. Conversely, gaining too much weight can result in a loss of speed and agility. You can read more about RED-S HERE.

Let’s use cyclists and the FTP test as an example.

The FTP (Functional Threshold Power) test is a commonly used method among cyclists to determine their performance level. The test involves following a simple format. Firstly, a proper warm-up is essential to prepare the body for the exertion. Then, all measurements are reset, and the cyclist rides as hard as possible for a continuous 20-minute period. The average power output during this time is recorded, which represents the cyclist’s FTP number. To calculate the watts per kilogram (w/kg) ratio, this FTP number is divided by the cyclist’s weight.

For instance, let’s say a cyclist achieved an average power output of 210 watts during the 20-minute FTP test, and their weight is 70 kg. Dividing 210 by 70 gives us a result of 3 w/kg of body weight.

Now, let’s consider the impact of a weight gain of 5 kg on the cyclist’s performance. If the cyclist’s weight increases to 75 kg, and assuming their power output remains the same at 210 watts, the new w/kg ratio would be calculated as 210 divided by 75, resulting in 2.8 w/kg.

This drop in the w/kg ratio would have a significant impact on the cyclist’s overall cycling performance. The observation made by Greg LeMond, a former professional cyclist, is relevant in this context. LeMond noted that a loss of 2 pounds (approximately 0.9 kg) in weight was more beneficial for performance than a 2-point increase in hematocrit values (a measure of red blood cell concentration).

In conclusion, maintaining an optimal weight and power-to-weight ratio is crucial for cyclists. Even small changes in weight can lead to noticeable differences in performance, and finding the right balance between weight and power output is essential for maximizing cycling performance.

Should individuals with an eating disorder have their body fat percentages calculated? After consulting with Kerry Gordon, a counselling psychologist on this matter, the answer is generally – Hold off. There are potential dangers associated with undergoing such tests that could have detrimental effects on the individual’s well-being.

In these circumstances, it is highly recommended to seek the guidance of a psychologist experienced in treating eating disorders as the primary step. Their expertise will assist in addressing the underlying psychological factors and developing a comprehensive treatment plan. Once psychological support is established, it can be beneficial to involve a registered dietitian who specializes in eating disorders. The dietitian can provide guidance in adjusting the individual’s diet in a manner that promotes a healthy relationship with food and supports their overall well-being.

The focus should primarily be on psychological healing and developing a healthy mindset towards food and body image. It is essential to approach the treatment of eating disorders holistically, with a multidisciplinary team that includes mental health professionals, dietitians, and other relevant healthcare providers, all working collaboratively to provide the best support for the individual’s recovery journey.

Let’s take a deeper dive –

General guidelines for ideal body fat percentages for endurance athletes:

Male Endurance athletes: 5-10%

Female Endurance athletes: 15-20%

How do you measure that?

There are several methods to measure body fat percentage, some of which are more accurate than others. Here are some common methods:

Skinfold Calipers: This method involves using calipers to measure the thickness of skinfolds at various sites on the body. These measurements are then used to calculate body fat percentage. This method is relatively inexpensive and easy to perform, but it requires some skill to obtain accurate results. This is the test that I can perform.

Bioelectrical Impedance Analysis (BIA): This method involves using a device that sends a small electrical current through the body to measure the resistance of body tissues. The resistance is then used to calculate body fat percentage. This method is non-invasive and easy to perform, but is not that accurate.

Dual-Energy X-Ray Absorptiometry (DXA): This method uses X-rays to measure bone density, lean tissue mass, and fat tissue mass. This method is highly accurate but also more expensive and requires specialized equipment.

Hydrostatic Weighing: This method involves submerging the body in water and measuring the displacement of water to calculate body volume. This method is highly accurate but also more expensive and requires specialized equipment.

The choice of method depends on several factors, including cost, availability, and accuracy required for the specific sport or individual needs. Skin fold measurements are the cheapest and are accurate.

When measuring skinfold thickness, it’s important to ensure that the same sites are measured each time and that the measurements are taken on bare skin with the subject standing upright and relaxed. For greater accuracy, it’s recommended to take the average of multiple measurements at each site.

The results are placed into a formula that looks like this –

Body density= 1.097 – (0.00046971 x sum of all of skinfolds) + (0.00000056 x sum of all of skinfolds squared) – (0.00012828 x age)

Body Fat Percentage (%) = [(495 / Body Density) – 450] x 100

Based on this analysis, we can derive results and establish guidelines regarding the optimal weight for competition. By referring to the suggested fat percentage table, it becomes evident that there is a 5-point range within which an athlete should ideally be. However, it is essential to acknowledge that this range allows room for individual experimentation.

Athletes vary in their response to weight changes, and personal preferences can greatly influence performance outcomes. Some athletes discover that they excel when maintaining a lighter weight, while others experience a decline in performance if they become too light. Each person’s response to weight fluctuations is unique and may require individual exploration and assessment.

It is crucial for athletes to listen to their bodies and closely monitor how different weight ranges impact their performance. By conducting personal experiments and observing the effects on their overall capabilities, athletes can determine the weight that optimizes their performance and maximizes their potential. Striking the right balance between weight and performance is a highly individualized process that demands self-awareness and continuous evaluation.

Hear is to maximizing racing performance without damaging ones health. For more on coaching click HERE. Pricing on what I offer can be found HERE. 

See you on the road,

Mike Roscoe.
Coach and Kinesiologist.