Which training intensity is best for increasing an athlete's power?

Increasing an athlete's power is best achieved through high-intensity training, and the optimal intensity for this purpose typically falls around 90% of one-repetition maximum (1RM). At this level of intensity, the athlete is able to recruit a significant number of muscle fibers and exert a high force output in a short amount of time, which is essential for developing explosive power. Training at this intensity stimulates the neuromuscular system effectively and promotes adaptations that enhance both strength and speed, key components of power.

Lower intensities, such as 75% and 50% of 1RM, while beneficial for endurance or hypertrophy, do not provide the same level of stimulus necessary to optimize power development. At these intensities, the force output is insufficient to elicit the high levels of muscle fiber recruitment and fast-twitch muscle fiber activation that are critical for improving power. Training at 100% of 1RM can be risky as it may lead to increased fatigue and a higher likelihood of injury, without necessarily providing additional benefits in terms of power adaptation compared to more controlled high-intensity efforts around 90%. Thus, the choice of 90% of 1RM aligns with established training principles focused on maximizing power output.