From the Guidelines
A typical body fat percentage for an 18-year-old female athlete is between 14% to 20%. This range is dependent on the specific sport, with endurance athletes like long-distance runners and swimmers often having body fat percentages on the lower end of this range (14-18%), while athletes in sports requiring more power or strength, such as volleyball or soccer players, might have slightly higher percentages (16-20%) 1.
Factors Influencing Body Fat Percentage
- The desire to achieve an 'ideal' body mass or composition for competitive success varies according to the demands of the sport and the specific position or role within a sport.
- A strategic, periodised short-term phase of energy deficit within an annual training programme may be necessary to achieve appropriate reductions in body mass/body fat for peak performance, but this should be guided by an experienced sport dietitian/nutritionist and/or physiologist and sports medicine physician 1.
- The strength of the association between performance and a specific body composition is limited by the lack of systematic investigation across sports, use of valid and comparable methodology, and standardised test protocols.
Health Considerations
- Extremely low body fat percentages (below 12%) can be detrimental to female athletes' health, potentially leading to hormonal imbalances, menstrual irregularities, decreased bone density, and increased injury risk—components of the female athlete triad.
- Optimal body fat levels should support both performance and overall health, including normal hormonal function and energy availability.
- Athletes may experience pressure to attain a certain lean 'athletic look' according to societal ideals of physique perceptions of athletes, or expectations within the sport, which can lead to problematic low energy availability (LEA) and negatively impact health and performance 1.
From the Research
Body Fat Percentage in 18-Year-Old Female Athletes
- The typical body fat percentage for an 18-year-old female athlete can vary depending on the sport and position played, but studies suggest that it is generally lower than that of non-athletes 2.
- A study of 25 female athletes aged 17-22 years found a mean body fat percentage of 24.11 ± 1.83% 2.
- Another study of female elite athletes found a median body fat percentage of 24.3% 3.
- It's worth noting that body mass index (BMI) is not a valid measure of body composition in female athletes, as it does not take into account lean mass and may overestimate obesity rates 3, 4, 5.
- Skinfold measurements and other methods of measuring body fat percentage are more accurate than BMI for assessing body composition in athletes 4, 2, 5.
Comparison to Non-Athletes
- A study of adolescent athletes found that 13.31% were classified as obese based on BMI, but only 5.95% were classified as obese based on skinfold measurements 4.
- Another study found that female athletes had a lower body fat percentage than non-athletes, with a mean body fat percentage of 24.11 ± 1.83% in athletes compared to 29.31 ± 3.86% in non-athletes 2.
Relationship Between Body Fat Percentage and Athletic Performance
- A study found a negative correlation between body fat percentage and VO2 max, a measure of aerobic capacity, in female athletes, although the correlation was not statistically significant 2.
- Another study found that drafted NFL players had a significantly lower body fat percentage than undrafted players, suggesting that body composition may be an important factor in athletic success 5.