Which intensity level is most closely associated with the training adaptation of muscle hypertrophy?

• A. Low intensity (about 30-40% of one-repetition maximum)
• B. Moderate to high intensity (about 70-85% of one-repetition maximum)
• C. Light intensity (below 20% of one-repetition maximum)
• D. Very high intensity (above 95% of one-repetition maximum)

Answer: (B)

Verified step by step guidance

1. Understand the concept of muscle hypertrophy: Muscle hypertrophy refers to the increase in muscle size due to resistance training. It occurs when muscle fibers are subjected to mechanical stress, leading to adaptations such as increased protein synthesis and muscle fiber growth.
2. Review the role of intensity in resistance training: Intensity is typically expressed as a percentage of one-repetition maximum (1RM), which is the maximum weight a person can lift for one repetition. Different intensity levels elicit different physiological responses in the muscles.
3. Analyze the relationship between intensity and hypertrophy: Research shows that moderate to high intensity (about 70-85% of 1RM) is most effective for stimulating muscle hypertrophy. This range provides sufficient mechanical tension and metabolic stress to promote muscle growth.
4. Compare the options provided: Low intensity (30-40% of 1RM) and light intensity (below 20% of 1RM) are generally insufficient to create the mechanical stress needed for hypertrophy. Very high intensity (above 95% of 1RM) may focus more on neural adaptations rather than hypertrophy due to lower training volume.
5. Conclude that moderate to high intensity (70-85% of 1RM) is the optimal range for muscle hypertrophy, as it balances mechanical tension, metabolic stress, and training volume effectively.