Strength training is gaining popularity in the fitness world – and it is now among the most popular physical activities for increasing muscular strength, muscular power, endurance, and hypertrophy (which refers to increased muscular size as a result of exercise).
For muscle growth, having periods of rest is just as important as working out. Why? Research shows that your rest intervals can directly affect your training outcome – so it isn’t just about giving your muscles a break, so you don’t pass out! 
But how long you should let your muscles rest for is a question commonly asked in the fitness industry.
Is there one straightforward answer? As it turns out, the recommended length of your rest interval varies depending on your reason for entering the gym in the first place!
In this post, we’ve really dug into the science for you – and provided an answer to this common question. So, if you want to know how long you should rest between sets based on your fitness goal, read on to find out!
What Are We Defining As A Rest Period Between Sets?
The rest period between sets refers to the amount of time you spend recovering between sets of resistance exercises.
There are two types of rest periods – such as active rest (you’re jogging in place, jumping jacks, or doing push-ups) or passive rest (which means you’re just standing, lightly walking around, or sitting down).
Active rest means you’re keeping your heart rate elevated, while passive rest allows your heart rate to drop as quickly as possible.
If you’re weightlifting, taking an active rest may mean incorporating supersets or circuits into your training routine. The key is to train a different group of muscles during your active rest, so you can rest your muscles to continue with the sets after you’ve rested.
What active rest does is giving you an aerobic workout – as well as cutting down on the total amount of time needed for a complete workout!
What is the Optimal Rest Interval Between Sets?
And now, onto the golden question! As mentioned above, the amount of time you rest between sets depends on your fitness goal.
For example, you could be training for one or a few of the following reasons: aesthetics, absolute strength, weight loss, or improving your muscular endurance.
The rest periods will be different for each of these goals – because what you’re aiming to do to your muscles is different.
Your Goal: Muscular Strength
Expert sources suggest that for building strength, having slightly longer rest periods would be beneficial – meaning that you should rest for at least 2 to 5 minutes between sets. 
Having a 2 to 5-minute rest interval between sets may help prevent fatigue and leave you feeling more energized to do more.
You should use heavier resistance when building muscular strength – and aim to complete 2-6 sets of 4-8 repetitions, according to the ACE (American Council on Exercise). 
Your Goal: Muscular Hypertrophy
Now, if your goal is muscular hypertrophy, the recommended rest periods are shorter.
If you’re training to bulk up and increase your muscle size, your rest intervals should be between 30 and 90 seconds. These rest intervals are known as moderate rest periods.
The case for moderate rest periods comes from the belief that the increase in metabolic stress (or “burning” sensation) results in bigger, bulkier muscles. Shorter rest periods result in higher muscular fatigue, and that stimulates high acute levels of anabolic hormones and boosts buffering capacity. 
When aiming to bulk up, you don’t want your body to fully recover between sets – because building muscle requires tiring them out. However, you also want to rest long enough so that you can continue lifting a heavy-enough weight repeatedly to stimulate growth.
Which is why, moderate rest periods are recommended for muscle growth: the weights lifted are heavy enough to target the muscle fibers to maximize growth, while the fatigue experienced switches on the mechanisms that help you grow muscle.
Your Goal: Muscular Endurance
According to ACE (American Council on Exercise), if your goal is to increase muscular endurance, your rest intervals should be even shorter – not more than 30 seconds.
Additionally, a review of 35 studies supports this claim by showing that shorter rest intervals really are beneficial for muscular endurance. 
You should aim to complete 2-3 sets of 12-16 repetitions of each strength resistance exercise – with only minimal rest in between.
Overall, The Optimal Rest Time Appears To Be 3-5 Minutes
In general, several studies show that 3 to 5-minute rest intervals might be the optimum amount of rest between sets. An analysis of 35 studies showed that having 3-5 minutes’ rest allowed participants to do more repetitions over multiple sets as well as resulted in more strength (because of the higher intensity and volume of training achieved). 
Additionally, having 3-5 minute rest intervals resulted in higher levels of muscular strength – compared to 1-minute rest intervals.
Finally, having a 3-5 minute rest is safer and more reliable than going for just 1 minute or something in between. These rest intervals allow your body to replenish phosphocreatine stores that could result in higher muscle strength.
The Amount Of Time Can Be Different For Beginners
Where you are presently also matters when deciding how long you should rest for between sets.
If you are a seasoned bodybuilder, it is natural that your body will need shorter rest periods compared to the newbies at the gym.
If you are fairly new to resistance training, you should aim to keep the training volume relatively low at first. Going into resistance training and beginning to torture your muscles with super heavy weights and short rest periods in between could cause more harm than good – so don’t overdo it.
The key is allowing your body to adjust to the new training program and the training stress. This will help you achieve better results in the long run, feel more successful, as well as make it more likely that you will stick to the program.
Focus on the Quality of the Movement
Finally, what matters greatly is the technique with which you perform each exercise set.
Your main goals when doing resistance training should be to perform each set with proper technique – rather than focusing on the number of repetitions, or the rest interval.
You should be focusing on completing each exercise with your full attention, focusing on the quality rather than the number of repetitions. Doing that helps minimize the risk of injury – as well as make sure each exercise targets the muscles effectively.
To sum up, how long you rest between sets is an important element of your training routine. It directly impacts the efficiency, safety, and effectiveness of your strength training program – so make sure you give it proper attention.
There’s no perfect amount of rest between sets – the amount of time you rest between sets will directly depend on your fitness goal.
If the reason you’re lifting weights is that you want to gain muscular power and strength, you’ll need to rest for a more extended period (such as 2 to 5 minutes). However, if bulking up is what you’re after, a rest of 30 to 90 seconds will help you achieve your goal. And, finally, if you’re aiming to gain muscular endurance – your resting intervals should only be about 30 seconds.
So, next time you think about cutting your resting interval short, think again. Make sure it’s the right thing for you – and your fitness goals.