It used to be that hardly anyone paid attention to rest intervals between sets. You'd just do another set when you felt like it, putting as much thought into it as you might in deciding when to lean over and grab another handful of salted nuts from the crystal bowl on the coffee table.
Then Charles Poliquin came along and convinced everybody that rest intervals were one of the most important variables in resistance training, pontificating, in his way, that there was an inverse relationship between intensity and rest periods.
In other words, the heavier the weight, the more time you needed between sets for neural recuperation. For instance, if you did a set with 85% of your 1RM, you needed to rest about 3 minutes before doing the next one.
That way, you stood at least a fighting chance of being able to sustain those reps over multiple sets because, the greater the volume of high-intensity reps, the greater the strength gains.
More recently, powerlifters, backed by some solid research on the subject, have been resting for up to 4 to 5 minutes between high-intensity sets. However, no lifter that I'm aware of, and definitely no research team, has ever seriously explored the merits of waiting even longer between sets. Until now.
A group of exercise physiologists from Humboldt State University in Arcata, California, found that waiting 8 minutes between high-intensity bench press sets allowed you to do just as many reps for the fourth set as you did for the first.
The scientists recruited 15 resistance-trained male subjects and determined each lifter's bench press 1RM. The lifters then participated in three different bench press sessions, each time doing 4 sets to failure with 85% of their 1RM.
Subjects performed the exercise using three different rest intervals (2 minutes, 5 minutes, and 8 minutes) in a random, counterbalanced design (i.e., each possible rep sequence was used for the exact same amount of times).
The lifters who waited 5 minutes between sets were able to achieve a significantly greater amount of training volume than the lifters who rested 2 minutes between sets.
Likewise, the lifters who waited 8 minutes between sets did more total reps than the lifters who waited only 5 minutes between sets. In fact, the lifters that took 8 minutes between sets were able to do the same number of reps for each of their 4 sets.
The researchers, writing in their report, concluded the following:
"Resistance-trained men, with the goal of greater volume during strength training, would benefit from longer rest intervals, specifically using an 8-minute RI between 4 consecutive sets of bench press exercise."
This study brings up several other questions. For one, would it apply to other major body parts? It's not far fetched to think it might also apply to deadlifts, squats, and rows, but would you really have to wait 8 minutes between sets of shoulder presses? Biceps curls?
Probably not, although the point about the strength-building benefits of taking longer rest intervals in general applies to smaller body parts too. Of course, in their case, rest intervals of 2 or even 3 minutes might work as well as 8 for the major body parts.
Then there's the 8-minute time waiting period itself, which seems like a g-damn eternity. You could make some oatmeal, pay some bills, memorize the first few stanzas of "The Song of Hiawatha" by Henry Wadsworth Longfellow, and call your insurance company, be put on hold, and actually reach an actual human being quicker than 8 minutes.
There are probably ways to make an 8-minute waiting period workable, though. You could consider working antagonistic body parts like chest and back together:
- Do a set of bench. Wait 4 minutes.
- Do a set of rows. Wait 4 minutes.
- Do your second set of bench presses, and so on.
Alternately, you could use that lengthy rest interval to stretch, practice mobility, or work small body parts that wouldn't interfere with the movement you're resting up for.
Even if you don't want to adopt 8-minute rest intervals between heavy sets, you should at least consider the overall point of their findings, if not the actual practice of them. And by that I mean you might want to take longer rest intervals than you're currently taking.
Too many lifters have been ensorcelled by CrossFitters and HIIT people into thinking that rushing around the gym and tossing weights around without taking any/much rest is somehow a barometer of how serious people work out. It's like emulating premature ejaculators in the belief that doing it faster and getting it over quicker is somehow better.
- HernandezDJ et al. Effect of Rest Interval Duration on the Volume Completed During a High-Intensity Bench Press Exercise. JJ Strength Cond Res. 2021 Nov 1;35(11):2981-2987. PubMed.