ISSA Nutritionist Practice Exam

What effect is megadosing with niacin most likely to have on a client looking to increase athletic performance?

1. Increased muscle mass

2. Decreased endurance

3. Early onset fatigue

4. Improved recovery time

The correct answer is: Early onset fatigue

Megadosing with niacin can lead to early onset fatigue in clients attempting to increase athletic performance. Niacin, also known as vitamin B3, is known to cause flushing and a variety of side effects when taken in high doses due to its vasodilatory effects, which can increase blood flow and cause discomfort. These effects can divert energy away from athletic performance and lead to a decrease in overall stamina and endurance. In addition, high doses of niacin can cause gastrointestinal issues such as stomach upset or nausea, which can further contribute to early fatigue during physical activity. The body may also experience metabolic disruptions, leading to less efficient energy utilization, resulting in the athlete feeling fatigued earlier than they normally would during their workouts or competitions. While some potential benefits of niacin include improved blood lipid profiles and possibly aiding in recovery, these do not directly translate to enhanced athletic performance, making the possibility of fatigue the most likely outcome from such megadosing.