Rest is there so the next set can match the last one. The American College of Sports Medicine position stand pairs heavy sets of 1 to 6 reps with 3 to 5 minutes of rest, and hypertrophy work of 6 to 12 reps with 1 to 2 minutes[1]. Shorter rests cost reps in the sets that follow[3].
| Kind of set | Rest reported |
|---|---|
| Heavy loads, 1 to 6 reps | 3 to 5 minutes[1] |
| Hypertrophy work, 6 to 12 reps | 1 to 2 minutes[1] |
| Power, light loads moved fast | 3 to 5 minutes[1] |
| Muscular endurance, more than 15 reps | Under 90 seconds[1] |
| Trained men, 8 to 12 reps, 8 weeks | 3 minutes gave more strength and thigh muscle than 1 minute[2] |
Willardson and Burkett had fifteen men do four sets of squat and bench press at an 8-rep-max load, resting 1, 2 or 5 minutes between sets. Total reps were highest with 5 minutes and lowest with 1[3]. Heavy here means close to a one-rep max, which the one-rep max calculator estimates from a recent set.
In that study, five minutes of rest beat two, and two beat one, in reps completed.
Your reps show the effect of rest
A training log records rest as rep counts. Four sets at one weight that read eight, eight, seven, six show reps falling across the sets, the drop the rest-interval studies measure. Four sets of eight show none.
Where the session time goes
Rest takes most of the clock in a strength session. Twenty working sets with two minutes between them is 38 minutes of rest before any lifting is counted. A timer that starts when you log a set turns that time into a number you can see.
Why the guidance gives ranges
The position stand gives rest as ranges tied to the load and the goal, not as one number, and says its recommendations should be applied in context: the person’s goals, physical capacity and training status[1].
Sources
- [1]American College of Sports Medicine. American College of Sports Medicine position stand. Progression models in resistance training for healthy adults. Medicine and Science in Sports and Exercise 41(3):687-708, 2009. doi.org/10.1249/MSS.0b013e3181915670
- [2]Schoenfeld BJ, Pope ZK, Benik FM, et al. Longer interset rest periods enhance muscle strength and hypertrophy in resistance-trained men. Journal of Strength and Conditioning Research 30(7):1805-1812, 2016. doi.org/10.1519/JSC.0000000000001272
- [3]Willardson JM, Burkett LN. A comparison of 3 different rest intervals on the exercise volume completed during a workout. Journal of Strength and Conditioning Research 19(1):23-26, 2005. doi.org/10.1519/R-13853.1