Adequate sports nutrition is often overlooked as a contributing factor to fatigue. In many cases, a simple change in eating habits with the help of a dietitian can increase energy levels and improve performance. Fatigue is largely caused by an imbalance of energy, carbohydrate, protein and fat. Unless addressing a specific deficiency (e.g. iron), supplements will do little to reverse the problem.
Eating insufficient carbohydrates combined with regular training can result in gradual depletion of muscle fuel (glycogen) stores leading to fatigue, lack of energy to train, loss of muscle mass and poor recovery. It is, for this reason, that weight loss if not planned carefully can lead to fatigue.
Dehydration impacts on exercise performance and may reduce decision-making ability and skill level. Possible signs of ongoing dehydration are general lethargy, dry skin, headaches, nausea and poor concentration. Individuals with high sweat rates should be particularly careful about meeting their fluid needs.