BMI is particularly inaccurate for people who are very fit or athletic, as their high muscle mass can classify them in the "overweight" category by BMI, even though their body fat percentages frequently fall in the 10–15% category, which is below that of a more sedentary person of average build who has a "normal" BMI number. For example, the BMI of bodybuilder and eight-time Mr. Olympia Ronnie Coleman was 41.8 at his peak physical condition, which would be considered morbidly obese. Body composition for athletes is often better calculated using measures of body fat, as determined by such techniques as skinfold measurements or underwater weighing and the limitations of manual measurement have also led to new, alternative methods to measure obesity, such as the body volume indicator.