The idea of training to failure started officially with Thomas DeLorme, M.D., after WWII. He used a protocol of three sets of 20 repetitions taken to failure. Training to what is called “momentary muscular failure” is still believed by most to be an essential factor in promoting strength gains. Many do not realize that this idea has never been officially tested in trained bodybuilders, who are more interested in size than strength, so researchers decided it was time to find out.


Australian researchers compared training to failure with stopping two reps short of failure. In this protocol, those who took each set to failure performed six reps per set, while those who stopped short of failure performed four reps per set. All subjects used 85% of their 1RM. A cross-sectional area of the biceps was measured before and after 12 weeks of training. The non-failure group took one set to failure each week to ensure they were still using their 6RM weight throughout the training period.


After 12 weeks, there was no difference between the two groups.


Taking all sets to failure is not necessary to maximize growth, even in trained lifters.


Previous research has shown that when using one’s 15RM weight, muscle activation reaches a plateau three to five reps before the point of failure. If the stimulus for growth is at all tied to maximum activation of motor units, then this is accomplished before muscle failure occurs. So to better maintain form and reduce the risk of injury, stop most sets a couple of reps before failure.