The body fat percentage is the ratio of body fat to body weight. 

When we talk about a lower body fat percentage, we use to associate it with a good body shape, but is a lower body fat percentage better? 

To answer this question, we must understand the role of fat in our bodies.

Fat has the function of providing energy, maintaining body temperature, and protecting internal organs. Fat is an important nutrient for the functional balance of the body, and it gives 9kcal/gram, which means that no other nutrient (as carbohydrates or proteins) gives the same energy.

So, for athletes who want to improve their performance, what does body fat percentage mean?

Body fat affects physical fitness and sports performance. This means that it affects different systems and functional capabilities of the human body, necessary for speed, strength, endurance, agility, and flexibility improvement.

In general, the adequate body fat percentage of men is lower than that of women. Other factors contribute to differences in the appropriate amount of BF%, as age and genes. Regarding athletes, their body fat percentage is commonly lower when compared with an average person.

The body fat rate of male athletes is usually between 6%-13%, and the body fat percentage of female athletes is between 14-20%. It’s not useful to focus on a specific value since there are differences between individuals. However, these references can guide training plans.

Among top marathon runners, the body fat percentage of male athletes is around 5%-11%, and that of female athletes is around 10%-15%. This body fat rate guarantees that will provide enough energy for the body without impairing endurance.

There are different formulas for calculating body fat percentage and the health professional should choose what fits better in each situation.

References:

Fields, J. B., Merrigan, J. J., White, J. B., & Jones, M. T. (2018). Body Composition Variables by Sport and Sport-Position in Elite Collegiate Athletes. Journal of Strength and Conditioning Research, 1. doi:10.1519/jsc.0000000000002865 

Mahan, L. K., & Escott-Stump, S. (2000). Krause's food, nutrition, & diet therapy. Philadelphia: W.B. Saunders.