The rest period between exercise sets is one of the variables you can tweak to change the stimulus you place on the muscles you’re training. The length of time you rest between resistance sets should depend on the resistance you’re using and your training goals. It’s during the rest between sets that your muscles partially replenish their energy stores so they can generate force again. Therefore, the time you rest can impact your performance when you train. So, how long should you rest between sets?
If Strength Building Is Your Main Goal
If your main objective is to build strength, the ideal formula is to choose a heavy resistance since lifting a heavy load maximizes strength gains. In general, a resistance that allows you to complete three to five reps before the muscles are exhausted works best for maximal strength gains. Because you’re using a heavier load, you won’t be able to do as many reps before your muscles fatigue. Once your muscles are exhausted, they have to partially recover to generate the same amount of force. Depending upon the length of the rest period, the recovery can be partial or almost complete.
For strength gains, you’re maximizing the amount of weight you lift on each set. Since you’re using a heavy load, your muscles will need more time to recover between sets. Adding extra recovery time means they can generate more force on the next set. So, in general, rest periods are longer when the goal is to build brute strength.
How long should you rest between heavy lifts? Two minutes would be the minimum, but many powerlifters rest even longer between sets, as long as three to five minutes. Resting longer gives your muscles more time to gear up for the next set.
If You’re Trying to Get Fitter and Leaner
What if your main objective is to get fitter and leaner rather than to build muscle size or strength? In this case, lift lighter and do more reps. This approach primarily builds muscle endurance and increases general fitness. Since you’re not using heavy weights, where you need longer recovery time, the rest periods between sets is short.
In fact, you can do a circuit workout where you whip through exercises in quick succession with little or no rest between exercises. The need for muscle recovery and regeneration of energy is less since you’re not completely depleting muscle energy reserves. In addition, moving quickly from exercise to exercise burns more calories than standing around
If You’re Trying to Increase Muscle Size
If you’re trying to boost the size, or hypertrophy, the muscles you’re working, a moderate rest period can help you achieve your objective. For hypertrophy gains, moderate resistance works best because you can do more repetitions using a moderate weight than you can using the heavy resistance you need to maximize strength gains.
For hypertrophy gains, choose a weight that allows you to do 8 to 10 reps before the muscle is thoroughly fatigued. Since you’re not using an ultra-heavy resistance, as with strength building, the rest period can be shorter, between 60 and 90 seconds. Shorter rest periods, as opposed to the several minute rests you use for strength gains, create more metabolic stress and that favors muscle hypertrophy.
Studies don’t universally support this though. In fact, there was a small study showing a longer rest period may be best for both strength and hypertrophy gains. In the study, 21 guys performed resistance training using either long or short rest periods between sets. The short rest group rested one minute between sets and the second paused for three minutes.
The results? At the end of eight weeks, the long rest group enjoyed greater strength AND hypertrophy gains. The likely reason is the longer rest group was able to perform more total volume when they rested longer between sets. Keep these results in mind when deciding how long your rest periods should be. Extending the rest period a bit to two or three minutes may stimulate greater muscle gains over time by allowing you to do more total volume.
On the downside, you get less metabolic stress, another driver of muscle growth. You can always vary the time you rest between sets during different training sessions or periodize your workouts so you vary your training variables, including rest between sets.
The Conclusion
How long you should rest between sets depends on the resistance you’re using and what you’re trying to achieve. If you’re after brute strength, go heavy on the weight and rest for two to three minutes between sets. For fitness gains without marked changes in muscle size or strength, lighten up on the weight, do high reps, and rest minimally between sets.
Hypertrophy falls somewhere in the middle. Moderate weights and moderate rest between sets. Rest periods can be as short as 60 seconds, but as long as three minutes may be ideal, based on one study. Know your goals and adjust resistance, total training volume, and rest periods based on those factors.
References:
Greatist.com. “How Long Should You Rest Between Strength Training Sets?”
Fitness Prescription. February 2004. pages 152-153.