Mary is a cross-country runner whose coach has asked her to decrease her total body fat to 7 percent Will Mary's performance increase at this lower percent body fat?

Mary's coach is an idiot. Cross-country running requires a great deal of nutritional stores in the body. Fat is our biggest long-term nutritional store. Fat has 9 calories per gram. Carbohydrates have only 4 calories per gram. Cross-country running will use carbohydrates for energy first. Then the fat stores will be used for energy. Once the fat stores are gone, the body will start to use protein - our your muscles. Hard to run without muscles.