JaMarcus Russell shares ideal NFL comeback scenariohttp://www.usatoday.com/story/sports/nfl/2013/04/09/jamarcus-russell-nfl-comeback-scenario/2069203/I don't know what JaMarcus Russell's personal trainers are using to calculate his body fat percentage, but this online BMI "Body Mass Index" calculator (link below) comes up with a slightly different answer.
Type in his height (6 feet 6 inches), weight (288 lbs), then click "Compute BMI".....and you'll get 33.3% body fat. Between 25-30% is considered "overweight". Above 30% is considered "obese". Oh, but he's only 15%....I forgot.
To be fair, the most accurate method is to weigh you in a tank of water. Otherwise, just using height and weight, there's no way of knowing how much of your weight is muscle and how much is fat. But still, I kind of doubt he's 15% body fat, even in a tank. Or on the moon!
http://www.nhlbi.nih.gov/guidelines/obesity/BMI/bmicalc.htm