Traditionally, bodybuilders are known to cut their rest periods intentionally short. This might entail resting less than a minute between sets of an exercise, if not performing (agonistic) supersets (e.g. tricep pushdowns followed immediately by skull-crushers). However, research usually finds benefit to longer rests between sets. 

RESEARCH SUMMARY: 

To begin, de Salles et al. (2009) reviewed 35 studies, assessessing how rest intervals affect strength and performance. This analysis determined that resting longer inter-set rests led to *more* total repetitions performed across sets. Furthermore, resting for 3-5 minutes improved strength gain over time.

Similarly, Henslemans and Schoenfeld’s 2014 review found that longer rest intervals (2.5+ mins) seem to benefit muscle growth, perhaps via increased training volume. However, rest interval length had just a *minor* effect on muscle growth. In fact, only 1 of the 5 studies analyzed showed significant differences in muscle cross-sectional area between study groups.

Nevertheless, shorter rests had never been shown to improve hypertrophy. That is, until Villanueva et al. (2015) showed that training with 1-minute rest periods produced greater gains than training with 4-minute rests. More specifically, the group resting less gained *more* lean mass and strength, despite performing the same training protocol. So, are shorter rests better for gains?

In order to find out, Grgic et al. (2017) systematically reviewed the literature on rest periods, analyzing 6 studies in total. They defined long rest periods as >60 seconds, and short rests as ≤60 seconds.

While data were limited, long rest intervals seemed to outperform short rests, providing ~37% more hypertrophy on average (9.2% vs. 5.8%). This finding was supported by (limited) MPS data, which showed more protein synthesis with longer rests.

As such, it seems like resting for 3-5 minutes between sets can boost muscle and strength gain.

SHOULD WE EVEN WORRY ABOUT REST INTERVALS? 

All told, unless you need to rush your workouts, you probably shouldn’t worry about rest between sets. In fact, mounting evidence supports the use of auto-regulated rest intervals. 

Recently, Ibbott et al. (2019) showed that 15 of 16 subjects resting intuitively were able to complete 5 sets of squats at 5RM. Given no time limit, subjects wound up resting 4-5 minutes between sets, which allowed them to complete 99.3% of their assigned volume (i.e. 794 of 800 possible reps). 

In fact, subjects were simply told to choose “a rest period you feel will allow you to complete a maximal effort during your next set.” 

Hence, if you focus on performing “high-quality” volume, you’ll probably rest for long enough between sets.

Additionally, one study showed that lifters resting intuitively took 2.6 minutes between sets, on average. This nearly matches the “optimal” rest length of 3-5 minutes, further suggesting that you can roughly tell if you’ve rested enough.

All considered, so long as you don’t cut rest periods intentionally short, you can just rest intuitively; for as long as you need.

CAN SHORT RESTS EVER HELP? 

While longer rests between sets provide modest benefit, there is certainly a place for shorter rest intervals. For example, if gym time is limited, it may actually be *better* to cut your rest periods short. 

Recall, the benefits to resting more between sets appear to be volume-mediated. In other words, long rests seem to help, but only given their effects on training volume.  

So, when training time is limited, shorter rests allow you to complete more sets. This would ultimately net you more total training volume (thus, probably better gains) than resting between sets would. 

While cutting rests short to allow for more volume is sub-optimal, doing enough volume is much more important for muscle and strength gain. 

ANTAGONIST SUPERSETS: A WIN-WIN? 

While you could cut rest intervals short to do more sets, a better alternative exists. Indeed, antagonistic paired sets/supersets provide a viable time-saving strategy.

Antagonistic supersets involve performing a set for one muscle group, shortly following a set for its opposing muscle group. For example, you could do biceps curls right after tricep pushdowns, back work after chest work, or hamstring exercise following quadriceps exercise. 

In a crossover trial, Paz et al. (2017) showed benefit to using antagonistic supersets. While one group performed seated rows immediately following bench presses, another rested between straight sets of each exercise. 

Despite taking roughly *twice* as long to complete the workout, those doing straight sets did *no* more volume than those performing paired sets. In fact, the paired-set group completed *more* reps across 3 sets. 

In general, antagonistic paired sets lead to similar or better volume and repetition performance, but with greater time-efficiency [2,3,4]. As such, if you want to finish your workouts faster without hurting performance, try antagonistic supersets. 

NOTE: Powerlifters may not want to use antagonistic paired sets for pre-meet bench training. Your pre-meet training should probably mimic the training style you’ll use at the meet. 

MAXIMIZING YOUR TIME BETWEEN SETS: 

Even if you’ve ample time to train, or dislike antagonistic paired sets, you can still benefit from a different rest strategy. More specifically, antagonistic stretching or light aerobic exercise between sets may improve performance. 

Antagonistic stretching, like antagonistic supersets, involve stretching the opposing muscle group following a set of an exercise. For instance, stretching the quadriceps after a set for hamstrings. This has shown to improve repetition performance [2], thereby increasing total training volume across sets of an exercise. 

Likewise, light aerobic training (e.g. walking briskly or jogging in place) between sets has shown to improve repetition performance or reduce RPE (perceived exertion). However, you should probably just sit or lie down after taxing exercise (e.g. a hard set of squats). 

RECOMMENDATIONS: 

In summary, resting for 3-5 minutes between sets should maximize gains, while antagonistic supersets may allow you to save time. Although, you can probably get away with shorter rests on less taxing, “assistance” movements.

For bodybuilders, it’s efficient to perform antagonistic paired sets, then rest for 2-5 minutes between supersets (e.g. work chest-> work back-> wait 3 minutes -> repeat).

For powerlifters, you can follow the same recommendation when doing assistance work, but you’re better off resting a full 3-5 minutes between sets of the competition lifts.

CONCLUSIONS AND TAKEAWAYS: 

1. Longer rests (>1 minute) between sets can enhance hypertrophy. 

2. Long (3-5 minute) inter-set rest intervals seem to improve strength gains. 

3. Rest periods matter for gains, but not as much as training volume. 

4. You can rest intuitively between sets, so long as you don’t intentionally cut rest periods short. 

5. Antagonistic supersets can save you time in the gym, without harming volume or performance. 

6. Doing “antagonistic stretches” or *light* cardio between sets may boost repetition performance.