Research Review Shorts: Short vs Long Rest Intervals for Muscle Growth
30-90 second rest intervals have been commonly touted as being the most ideal when training for hypertrophy. Research over the past few years has put this hypothesis to rest, and this study in female lifters gives even more creed to longer rest intervals.
How long do you rest in between sets at the gym? 30 seconds? 1 minute? Two minutes?
For a while, 30-90 rest intervals were recommend for hypertrophy specifically. The thought was that these short rest intervals would cause a substantial increase in anabolic hormones deemed, “The Hormone Hypothesis”.
Over the years a few studies have put the hormone hypothesis to rest. In these studies longer rest periods (2-3 minutes) consistently seem to lead to more muscle and strength improvements.
The mechanism here is quite obvious; longer rest yields greater muscle growth as it allows lifters to maintain training loads better for each set than shorter rest, enabling more total volume to be performed.
We always knew that for strength purposes, long rest period are a must, however it was starting to seem that the same goes for hypertrophy training as well.
Most of the research on this topic were conducted in male populations. This current study being reviewed is on trained women.
14 women perform four sets to failure at 75% of their 10-repetition maximum (RM) on the chest press and leg press, while resting for either one or three minutes between sets.
The researchers assessed total volume performed and the acute blood lactate response.
The researchers hypothesized that the rate of decline in reps would be uniform from set-to-set in both conditions, and total volume performance would be greater in the three-minute rest condition.
- The Female participants performed significantly more volume on both the chest press (+33.01%) and leg press (+33.60%) in the three-minute rest condition.
- Participants performed more reps on sets two, three, and four in the three-minute condition than in the one-minute condition.
- Blood Lactate levels did not differ between conditions.
Interpretation & Takeaways
These findings confirm that set-to-set rep performance is better-maintained with longer rest intervals, leading to more total volume when sets are equated between short and long rest training.
The interpretation could easily be that lifters should use longer rest intervals of about three minutes for every set of every exercise..
Although that simple interpretation is generally good advice, it’s a bit simplistic. Short rest periods still have there place—rest-pause sets, agonist-antagonist superset training, taxing the cardiovascular system, and especially, if you have other shit to do.
Sure 3 minute rest intervals may be the most ideal for certain individuals, but sometimes you just need to keep your workout to 45 minutes and placing 3+ minutes of rest in between sets would cause you to go over time and then have to cut out sets of the workout anyway.
The biggest takeaway I believe is that we can drop the notion that 30 seconds rest periods are the most ideal, and depending on what your goal is it may be the least ideal. Knowing we can relax a little bit in between sets and in doing so may get us better results is certainly reassuring.