What percentage of predicted maximum exertion should be used for the initial 5-10 reps in a 1 RM test?

For the initial 5-10 repetitions in a one-repetition maximum (1 RM) test, utilizing 40-60% of the predicted maximum exertion is appropriate for several reasons. This percentage allows for a warm-up that is essential for preparing the muscles and joints for heavier lifting without causing undue fatigue.

Starting at this lower intensity helps in establishing a baseline for the individual's strength levels while ensuring that the muscles are sufficiently engaged and warmed up. It minimizes the risk of injury by allowing the body to adapt to the movement and load before incrementally increasing the intensity. This approach is particularly beneficial for clients who may be new to resistance training or attempting a 1 RM for the first time, as it promotes better performance and safety.

Higher percentages, such as those in the ranges of 70-80%, 50-70%, or even 30-50%, would risk fatigue or improper form due to the increased load, which could compromise the effectiveness of the lift and raise the potential for injury. Therefore, the most suitable choice is the 40-60% range, which strikes an optimal balance of readiness and safety for the initial repetitions.