Which of the following hormones is NOT an important factor in muscle hypertrophy?
A. Androgens B. Beta-endorphins C. Human growth hormone D. Testosterone
The correct answer and explanation is:
The correct answer is B. Beta-endorphins.
Explanation:
Muscle hypertrophy refers to the increase in muscle size due to an increase in the size of individual muscle fibers. Various hormones play critical roles in this process, but beta-endorphins are not one of the key players.
- Androgens (A): Androgens, which include testosterone, play a crucial role in muscle hypertrophy. They promote protein synthesis, increase the retention of nitrogen in muscle cells, and contribute to the enlargement of muscle fibers. These hormones also stimulate satellite cells, which are important for muscle repair and growth.
- Beta-endorphins (B): Beta-endorphins are neuropeptides that are primarily involved in pain relief and the regulation of mood. While they can be released during exercise, particularly during intense or endurance activities, they are not directly involved in muscle hypertrophy. Their role is more related to reducing pain and improving the perception of exercise, but they do not significantly influence muscle growth or the repair processes that lead to hypertrophy.
- Human growth hormone (C): Human growth hormone (HGH) is vital in muscle growth. It stimulates the release of insulin-like growth factor 1 (IGF-1), which plays a direct role in muscle tissue growth and repair. HGH also increases protein synthesis and enhances the recovery process after exercise, contributing to muscle hypertrophy.
- Testosterone (D): Testosterone is one of the most well-known hormones involved in muscle hypertrophy. It directly affects muscle growth by increasing protein synthesis and reducing protein breakdown in muscle fibers. It also stimulates the proliferation of satellite cells, leading to muscle regeneration and enlargement.
In conclusion, while beta-endorphins play a role in pain management and mood regulation during exercise, they are not directly involved in the process of muscle hypertrophy like the other hormones listed.