NCSF Sport Nutrition Specialist Certification 2025 – 400 Free Practice Questions to Pass the Exam

Protein metabolism tends to be lowest during resistance training because this type of exercise primarily relies on glycogen stores and creatine phosphate for energy rather than directly utilizing protein. During resistance training, the body focuses on short bursts of effort with periods of rest, allowing it to predominantly use carbohydrates for fuel. While protein is essential for muscle repair and growth post-exercise, the immediate metabolic demands during the workout itself do not emphasize protein as a primary energy source.

In contrast, endurance running requires sustained energy over extended periods, leading to higher protein utilization as muscle tissues may be broken down for energy when glycogen stores are depleted. High-intensity interval training and circuit training also involve elevated energy expenditure, often relying on both carbohydrates and some contributions from protein. Thus, the metabolic role of protein is significantly heightened during these activities compared to the demands placed on the body during resistance training.