Masheen

Effort

Failure

Also called training to failure, muscular failure, going to failure, to failure

Failure is the point in a set where you try another rep and cannot finish it.

Did not go8 reps done
8 reps done, none left: the next rep did not go. Bench press, 70 kg: eight reps go up, the ninth stops halfway. 8 reps, 0 in reserve, RPE 10.

In plain words

Taking sets to that point on purpose is called training to failure. Lifters do not all mean one thing by it. A 2023 meta-analysis by Refalo and colleagues had to sort its studies by definition: momentary muscular failure, where a rep cannot be completed although you keep trying, and set failure for every other definition in the studies. A stricter everyday version is technical failure: you stop when you can no longer do a rep with the same form. Masheen uses one reading: failure is 0 reps in reserve, or RPE 10.

An example

Bench press, 70 kg. Eight reps go up. The ninth stops halfway and comes back down. That set went to failure: eight reps, none in reserve, RPE 10. The 2023 meta-analysis of 15 studies found no evidence that going to momentary muscular failure builds more muscle than stopping short of it, and a trivial advantage for failure (effect size 0.19) across all the definitions. The ACSM's 2026 position stand lists training to momentary muscle fatigue among the variables that did not consistently affect results.

Often confused with

AMRAP AMRAP is an instruction for a set, with no fixed number of reps; failure is where such a set may end. RIR Reps in reserve measures the distance from failure; at failure that distance is zero.
RIR RIR, or reps in reserve, is the number of good reps you could still have done when you stopped a set.
RPE RPE is a score from 1 to 10 for how hard a set felt, counted by how many more reps you could have done.
AMRAP AMRAP stands for "as many reps as possible": a set with no fixed rep number, where you keep going until you cannot do another good rep.
Drop set A drop set is a set taken to failure, after which you take weight off the bar and carry straight on with the lighter weight, with no rest.

Sources

  1. Refalo et al. 2023. Influence of resistance training proximity-to-failure on skeletal muscle hypertrophy. Sports Med 53(3):649–665 Read
  2. Schoenfeld, Ogborn, Krieger 2015. Effect of repetition duration during resistance training on muscle hypertrophy. Sports Med 45(4):577–585 Read
  3. Currier et al. 2026. ACSM Position Stand: Resistance Training Prescription for Muscle Function, Hypertrophy, and Physical Performance in Healthy Adults. Med Sci Sports Exerc 58(4):851–872 Read

Updated . How these pages are researched and corrected: editorial policy. Every term in the glossary.