Which of the following is NOT a sign of underfueling?

In the context of sports nutrition and the physio-biological responses to energy intake, increased energy levels are indicative of proper fueling rather than underfueling. When an athlete is adequately fueled, the body has sufficient energy to perform optimally during exercise and activities of daily living. This includes appropriate metabolic responses, maintaining stamina, and supporting recovery.

On the other hand, signs of underfueling typically manifest through various physiological and psychological symptoms. Bradycardia, or a slowed heart rate, can occur due to decreased energy availability, affecting normal cardiovascular function. Hypothermia may result from insufficient calories and nutrients, impacting the body's ability to maintain temperature regulation. Orthostatic dizziness is another sign, often linked to low energy availability and impaired blood circulation.

Therefore, increased energy levels signify that the athlete is well-fueled, making it the distinguishing factor among the other signs of underfueling. Understanding energy balance is crucial for athletes to ensure optimal performance and avoid the negative consequences associated with insufficient caloric intake.