Ask the average gym goer how much the rest between sets and you will get as many answers as people you ask. The answers vary from “I don’t take rests” to “until I feel ready to go” to “1 minute” to “the latest research says…”. Is there a best? In the age of optimization, we want to find the best way to do everything; however, as with most things in strength training, the answer falls closer to “it depends”. What are your goals? Are you training for something, or just general fitness? A lot of factors go into selecting rest times, but in this article, we are going to look at rest periods for strength training.
To perform a task, such as bench press, at a near maximal effort (1-3RM), we are going to use our Adenosine Triphosphate-Phospho-Creatine (ATP-PCr) energy system. This energy system is in the cell and provides up to 15-20 seconds of energy, after which, it needs to be restored. What if it doesn’t get restored? How does it get restored? Are we able to make it longer than 15-20 seconds?
The answer to all three of those questions resides in the topic “rest periods”. ATP-PCr is the primary immediate use, maximal effort energy system; however, it depletes quickly. The best examples of use are a 1RM lift, a 40yd sprint, etc. Repeated attempts in quick succession yield diminishing results, why? Because the energy system isn’t present to produce max output. This answers our first question; if the ATP-PCr system is not fully restored, our max effort will diminish.
So how does it get restored? Rest! The Phosphagen component of ATP and PCr is what gets depleted, with PCr being the most depleted with a maximal effort. While it provides a huge portion of energy, it takes a while to restore. Most of the replenishment occurs through glycolysis, which is an aerobic energy system. Heavy breathing after a max effort is in part due to Phosphagen replenishment. The time to replenish ATP is upwards of 5 minutes, with Creatine Phosphate upwards of 8 Minutes.
With this in mind 3-5 minutes is a great starting point for most. The stronger we get and the heavier the weight gets, rest times start getting stretched out more; so the rest time is a bit relative to our own strength. But if we rest too long, we may get “cold” and struggle with a heavier weight due to loss of potentiation.
Can we increase the amount of ATP-PCr and have a longer max effort? Kind of. Because it resides in the muscle, there is a finite space. But, through hypertrophy, we increase muscle size, which allows for more ATP-PCr. This is the reason why a bigger muscle is generally a stronger muscle. Supplementation with Creatine is also a benefit in strength because it allows a higher concentration of the phosphagen.
Hopefully, this demystifies rest periods in strength training. Shorter rest periods have other benefits, which will be explored in the future. Happy lifting and have a rest!
References
Fleck, S.J. & Kraemer, W.J. Designing Resistance Training Programs (3rd Ed) Human Kinetics.
Haff, G. G., & Triplett, N. T. (2016). Essentials of Strength Training and Conditioning (4th ed.). Human Kinetics.