Training to failure

Training to failure means continuing a set until the muscles can’t produce enough force to lift the load concentrically.^{1Schoenfeld, Science and Development of Muscle Hypertrophy, 2nd ed., p. 138.} How close a client gets to muscular failure is the usual gauge of intensity of effort.^{1Schoenfeld, Science and Development of Muscle Hypertrophy, 2nd ed., p. 138.}

The common argument for failure is that it recruits the most motor units, but the evidence for that is lacking.^{1Schoenfeld, Science and Development of Muscle Hypertrophy, 2nd ed., p. 138.} Most of a muscle’s motor units are recruited at loads as low as 30% of 1RM when effort is high, so proximity to failure matters more as loads get lighter.^{1Schoenfeld, Science and Development of Muscle Hypertrophy, 2nd ed., p. 138.} Failure may also add metabolic stress.^{1Schoenfeld, Science and Development of Muscle Hypertrophy, 2nd ed., p. 138.}

In practice

• Schoenfeld recommends most sets at 1 or 2 reps in reserve, with failure saved mainly for the last set of an exercise.^{2Schoenfeld, Science and Development of Muscle Hypertrophy, 2nd ed., p. 140.} He uses it more freely on single-joint movements than on multi-joint lifts.^{2Schoenfeld, Science and Development of Muscle Hypertrophy, 2nd ed., p. 140.}
• Three sets with an 8RM bench load might go 8, 6 and 5 if the first set hits failure, while stopping each at 7 could give 21 reps.^{3Helms et al., The Muscle & Strength Pyramid: Training, 2nd ed., p. 67.}
• In one study, a group training to failure made similar progress to one that didn’t but showed signs of overtraining.^{3Helms et al., The Muscle & Strength Pyramid: Training, 2nd ed., p. 67.} The most recent meta-analysis Helms cites found no strength advantage from training to failure.^{3Helms et al., The Muscle & Strength Pyramid: Training, 2nd ed., p. 67.}
• Constant failure training raises the risk of nonfunctional overreaching.^{2Schoenfeld, Science and Development of Muscle Hypertrophy, 2nd ed., p. 140.} Norton and Baxter suggest keeping most sets 1 to 3 reps short and going to failure only now and then.^{4Norton and Baxter, The Complete Reverse Dieting Guide, p. 111.}