NCSF Sport Nutrition Specialist Certification (SNS) Practice Test

What kind of molecules are released during exercise that signal positive muscle adaptations?

1. Amino acids

2. Free radicals

3. Electrolytes

4. Carbohydrates

The correct answer is: Free radicals

During exercise, free radicals are released, and while they are often viewed negatively due to their association with oxidative stress, they play an important role in signaling positive muscle adaptations. When muscles contract during physical activity, they produce reactive oxygen species (ROS), a type of free radical. These molecules act as signaling agents that can stimulate various pathways involved in muscle adaptation and growth, such as increasing the expression of antioxidant enzymes, promoting myogenesis, and enhancing mitochondrial biogenesis. This signaling cascade contributes to improvements in muscular strength, endurance, and overall fitness over time. In contrast, amino acids primarily serve as building blocks for protein synthesis and are essential for recovery and muscle repair but do not directly signal adaptations in the same manner as free radicals. Electrolytes are vital for maintaining fluid balance and nerve function during exercise but are not involved in signaling pathways for muscle adaptation. Carbohydrates are a primary energy source during exercise but also do not have a specific role in signaling adaptations at the molecular level like free radicals do.