Monday 4 October 2010

Athletes and Body Mass Index (BMI)

Many people are confused about what Body Mass Index (BMI) means as it relates to body fat. Keep in mind that it is just one tool to use when you are looking at your health. Scientists use BMI as a research tool to make objective comparisons as to how fat a person is. A person with a BMI of 25 or above is considered overweight and a BMI over 30 is considered obese.

BMI uses a person's height and body weight to measure a person's fatness. This method has some limitations because it doesn't consider an athlete's body type (slim, muscular, etc.) For example, athletes usually have high muscle mass and tend to have higher BMIs (suggesting the athlete is overfat). The athlete would actually be fit and healthy with low risk for fat-related diseases. So, even though BMI could be used as a starting point, an athlete's level of fatness is best measured using a direct method. Two methods used are under-water weighing and skinfold measurements. Under-water weighing is not readily available to most people. Having a skinfold body fat test with calipers done by a fitness professional is convenient and reasonably accurate.

Regular sports training, low body fat and increased muscle mass are all factors that should outweigh any health risks suggested by a higher BMI.