Why rest periods matter
Between sets, your muscles are partially replenishing phosphocreatine stores and clearing metabolic byproducts. The degree to which they recover determines how much force you can produce in the next set. Too little rest and your next set is compromised. Too much and you lose training density without gaining anything.
The practical consequence is that if you cut rest short, the quality of your sets drops, which reduces the training stimulus. You are doing more sets but getting less from each one.
What the research says
A 2024 Bayesian meta-analysis by Singer and colleagues examined rest period effects on hypertrophy outcomes across multiple studies. The finding was that rest periods above 60 seconds were clearly beneficial compared to very short rests. Beyond 90 seconds to 2 minutes, there was no consistent additional hypertrophy benefit from resting longer, though performance during the session continued to improve with longer rest.
Source: Singer N et al. The effects of rest interval duration on resistance training adaptations. Frontiers in Sports and Active Living, 2024.The ACSM position stand recommends 2 to 3 minutes for compound multi-joint exercises and 1 to 2 minutes for isolation exercises. These recommendations reflect the difference in systemic fatigue between exercise types.
Source: American College of Sports Medicine Position Stand. Progression models in resistance training for healthy adults. Medicine and Science in Sports and Exercise, 2009.Compounds need more rest than isolation
A compound exercise like a barbell squat or deadlift involves large amounts of muscle mass, heavy loads, and significant cardiovascular and neural demand. A set of squats is systemically taxing in a way that a set of leg curls is not. Resting 90 seconds after squats and then squatting again will produce a noticeably worse second set than resting 2.5 minutes.
Isolation exercises like curls, lateral raises, or calf raises are less systemically demanding. The relevant muscle group recovers faster because less total tissue was involved. One to 1.5 minutes is usually sufficient.
Practical rest guidelines by exercise type:
Compound exercises (squat, deadlift, row, press): 2 to 3 minutes.
Isolation exercises (curl, extension, raise, fly): 1 to 1.5 minutes.
Later in the session as fatigue accumulates: add 20 to 30 seconds to each.
Does experience level change things?
Yes. Beginners typically need more rest than experienced lifters for the same relative load, because their cardiovascular fitness and muscular recovery efficiency are both lower. A beginner doing their first sets of squats at moderate intensity needs as much rest as an experienced lifter doing the same movement at near-maximum loads.
As fitness improves, recovery between sets becomes faster. Experienced lifters often find they can manage with slightly shorter rest periods while maintaining set quality, particularly on isolation work.
What about training time constraints?
If you have limited time, the right answer is usually to reduce sets rather than rest periods. Cutting a session from 9 working sets to 6 and resting properly between each produces better outcomes than doing 9 sets with short rest between them.
Short rest periods are sometimes used intentionally in circuit training or metabolic conditioning, where the goal is cardiovascular fitness rather than maximising hypertrophy. For muscle building, the evidence is consistently against sacrificing rest time.
When is it acceptable to rest longer?
Always, if you need to. A rest period guideline is a floor, not a ceiling. If you finish a compound set and feel like you cannot produce a high-quality effort after 2.5 minutes, rest another minute. Completing 3 high-quality sets with 3.5 minutes rest between them is better than forcing 3 low-quality sets with 2 minutes rest.
This is particularly relevant when training with heavier loads or near the end of a session when cumulative fatigue is high.