It’s well established in the fitness community that rest helps stimulate the physiological changes that increase strength, endurance and leanness — not to mention that it prevents overuse injuries. But it’s not just the type of rest you take between workouts or the minute-long break you take between sets that matters — even the rest you nab between the repetitions of a single weightlifting set can help you bust through plateaus.
These brief intra-set recovery opportunities give your muscles just enough time to partially reverse some of the physiological fatigue factors that cause you to struggle in the last few reps of a set. This allows you to squeeze out a few more reps than you could without these “rest-pauses” — or, alternatively, to do your usual number of reps with slightly more weight.
Either way, the upshot is the same: By accomplishing a bit more work in each set, you build more strength.
Whether your goal is to build muscle size, increase strength or improve athletic performance, introducing rest-pause sets into your routine can help boost your performance — without spending more time at the gym.
The Rest-Pause Reaction
The mechanics of muscle fatigue are complex. Researchers have identified at least five separate factors that can contribute to it, including the depletion of the phosphate, or ATP-CP, energy system — a glucose-fueled chemical reaction in muscle cells. Rest-pause sets take advantage of the quick recovery of that system to boost strength.
“The ATP-CP energy system fuels short, high-intensity bursts of activity, such as those involved in a weightlifting set,” explains Chad Waterbury, MS, author of Muscle Revolution: The High-Performance System for Building a Bigger, Stronger, Leaner Body (self-published, 2007). This system can supply energy for about 15 to 30 seconds. Fatigue sets in when high-intensity efforts are sustained for longer than that and the ATP-CP system becomes depleted.
“It usually takes about three minutes to fully recover, but the process begins very quickly,” says Waterbury. “By allowing your muscles to relax for even five to 10 seconds, you’re giving the ATP-CP system enough time for muscle contractions to resume.” And that gives you an opportunity to get more strength gains out of every set.
In a standard weightlifting set, you maintain a steady tempo, pausing for only a fraction of a second between repetitions until your set is complete.
In a rest-pause set, you lift as you normally would until your muscles become fatigued to the point where you cannot complete another repetition at the same tempo. At that point, you rest for anywhere from five to 30 seconds, and then try to squeeze out another rep.
Repeat this process until a rest-pause isn’t enough to enable you to lift the weight again with good form.
Consider a standard set of barbell squats versus a rest-pause set of barbell squats. In a standard set, you might perform 10 repetitions using a weight that leaves your leg muscles severely fatigued after the 10th repetition. While mounting fatigue may cause your last few reps to be a little slower than your first few, you still barely pause between the lowering and lifting phase of the repetitions.
In a rest-pause set of barbell squats, you might use the same amount of weight and lift it repeatedly without pauses until fatigue causes your tempo to slow discernibly — perhaps after the eighth or ninth repetition. You would then allow your upper-leg muscles to recover by pausing in a locked, standing position. (Although your muscles will still be lightly active in supporting the weight of the barbell, they will still be able to replenish some of their ATP-CP energy stores.)
After five to 10 seconds (thanks to the muscle recovery achieved in the rest-pause), you’ll likely be able to complete another repetition at the same speed as the first rep of the set. You take another rest-pause after this repetition, and continue in this manner until you can no longer lift the weight at your original tempo, even with the rest-pauses.
Expect to extend your set by one to three repetitions compared with a conventional set using the same weight. Or, you might keep your number of reps the same as usual and add more weight instead. In this scenario, your tempo will probably slow after about seven repetitions. You can then use rest-pauses to complete the last three.
A Pause for Progress
Rest-pause sets are simple to do. To get the most out of them, follow these guidelines from our experts:
Know when to pause. The best time to insert a rest-pause is when doing so will most effectively help you to complete another rep, says strength coach Charles Staley, MSS, of Staley Training Systems in Gilbert, Ariz. Don’t pause too early, when your muscles are still fresh enough to complete more reps without a break. And don’t wait until your muscles are completely exhausted and therefore unable to squeeze out another rep, even with a rest-pause. “Once your lifting speed slows discernibly, that’s when you want to pause and gather yourself,” he says.
Rest-pause with appropriate exercises. Some exercises lend themselves to the rest-pause method better than others. “It doesn’t work well with exercises where you pause in a position in which you can’t really rest,” says Staley. In other words, you wouldn’t rest-pause during, say, the dumbbell shoulder press or the bench press.
Most machine and cable exercises are good choices, because you can fully relax in the starting position. Among free-weight exercises, the dead lift, barbell squat and dumbbell biceps curl are all good rest-pause choices. ˙
You can find others easily: If you can really rest in the start position, it’s a good rest-pause exercise. Otherwise, it’s not.
Increase weight gradually. Rest-pauses bump the work volume of your set, either by increasing the number of reps or the amount of weight you use. But how much more weight should you try to lift? “It depends on the movement,” says Waterbury, “but as a general rule, you can usually increase the load by 5 to 10 percent.”
Blend your sets. Rest-pause sets are just one effective tool for breaking through weightlifting plateaus, and because the body responds to variety, you’ll make the most progress if you employ various tools in a balanced way.
While rest-pause sets stimulate muscles in a way that conventional sets don’t, the reverse also holds true. Specifically, conventional sets better test muscles’ ability to resist fatigue during continual work — also an important attribute for many fitness pursuits. Therefore, a strength-training program that includes both conventional sets and rest-pause sets is better than one that includes only one or the other.
“I suggest using rest-pause sets for two weeks, every six weeks or so,” says Waterbury. “You can even blend the two workout types in multiweek progressions. For example, during your first workout, you might rest for eight seconds between dead-lift reps. Next workout, you’ll rest for seven seconds. You’ll continue to cut one second off the rest period until you can perform all the reps without resting.”
After completing such a cycle, increase your weight and start a new cycle.
“The downside to rest-pauses is that you lose your rhythm, and sometimes maintaining rhythm gives you a better chance of completing another rep than taking a short break,” says Staley. With practice and mindful attention to your muscles, you can learn to tell whether maintaining your rhythm or taking a quick break will have the greater effect on your chances of completing another repetition in any given set.
How do you know if you’re using rest-pause sets correctly? Just monitor your performance, says Staley. “As long as your performance is improving, you are using them correctly.”
Matt Fitzgerald is the author of several books on fitness and nutrition. Most recently, he coauthored Maximum Strength: Get Your Strongest Body in 16 Weeks With the Ultimate Weight-Training Program (Da Capo, 2008). For more information, visit www.mattfitzgerald.org.