High-load resistance training (>60% 1RM) is superior to low-load training for maximizing one-repetition maximum (1RM) strength gains, although significant strength gains can still be achieved with low loads if taken to failure.

Meta-analytic data of this metric shows a clear advantage to using heavier compared to lighter loads when the number of sets are similar between conditions. For example, a recent meta-analysis [10] reported a moderate to large effect size (ES) difference (ES = 0.58) favoring high- (>60% 1RM) vs. low- (≤60% 1RM) load training... It should be noted that while heavy load training is clearly requisite for maximizing 1RM, significant strength gains in this test are routinely observed with the use of low-loads (≥20 repetitions per set).