The Effect of Rest Interval Length on Upper and Lower Body Exercises in Resistance Training

Did you know that the rest time between sets during Resistance Training is intended for more than just taking selfies and strolling your social media feed? Have you ever wondered how long you should rest between sets? Millender et al.’s (2021) research helps us understand the importance of rest time and provides guidelines to consider for making the most out of each lifting sess.

Is it better to take a short or long rest between sets of the Resistance Training? Anytime this question is posed it typically opens the debate of quantity vs. quality. If we shorten the rest time, we can fit more sets into a shorter period, and doing so can result in a bigger spike in anabolic (aka muscle-building) hormones (yay for quantity).

On the flip side, if our rest time is too short then the quality of our exercise plummets, our body doesn’t have time to replenish the substrates needed to produce muscle contractions or remove the waste products associated with exercise (via the use of buffering protons and removal of lactate). As a result, we might experience reductions in our strength or power in subsequent sets (oh no, we lost quality).

Fortunately for us, through their peer-reviewed, randomized, repeated-measure study that was conducted with a sample of 14 experienced female lifters who ranged from 17- 28 years of age, Millender et al. (2021) found that longer rest times, of 3 minutes, were more effective when looking to increase total volume lifted (reps x sets x load). The longer rest time also reduced the lifter’s perceived fatigue level when performing leg press and chest press exercises. Interestingly, no significant difference was found in blood lactate concentrations between the shorter and longer rest times. 

So, what does this all mean? If you want to maximize the total volume that you are lifting on a given training day, longer rest intervals (3 minutes) between your sets are the way to go when training for muscle growth (hypertrophy training at low intensity with high volume). The authors elaborate on this by citing other research in the area which explains that total training volume (reps x sets x load) more directly influences hypertrophy and strength gains compared to anabolic hormone levels, which may decrease with longer rest times.

It is important to remember that any given research study investigates relatively narrow parameters with specific populations. The findings discussed here are specific to experienced female lifters who are into Resistance Training or hypertrophy via leg press and chest press exercises. You will want to dig deeper into the research to determine if these findings hold true for the population you work with and/or for the physiological adaptation you are chasing.

For more research articles like this check out the International Journal of Exercise Science (https://digitalcommons.wku.edu/ijes/) and/or see other ACE-Sponsored Research articles (https://www.acefitness.org/resources/pros/research-studies/)

Do you want to help others get the most out of their workouts?!? Consider enrolling in Elevated Learning Academy’s Personal Fitness Trainer Diploma program to arm yourself with the knowledge needed to help others maximize their efforts and reach their health and fitness goals.

You can find the full article here, or see the summary created by the American Council on Exercise here.