Over at Evidence Based Fitness, Bryan Chung reviews a study that looked at whether manipulating rest periods can aid in hypertrophy.
Rest 2 minutes, or less than 2 minutes, that is the question!
He explains the methods:
The subjects were then randomly assigned to do an 8-week lifting program in which the rest period was either constant (2 minutes between sets for 8 weeks) or decreasing (2 minutes between sets in week 1-2, and then decreasing every week to end up at 30 seconds between sets in week 8)
The program was 6 workouts a week, alternating between a workout A and B, Monday to Saturday. Both groups had the same exercises. In weeks 1 and 2, both groups resting for 2 minutes between sets. From week 3 onwards, the decreasing rest group got less and less rest between sets each week.
I particularly liked this paragraph, as it makes a point about the proper way to read a research article:
I think it’s important to pay attention to the characteristics of subjects in a study as it has direct implications as to whether this research might apply to any particular consumer. There were 20 subjects in this study (10 in each group). The subjects in this study group were, on average, in their 20’s, somewhere around 5’10" tall and 160lbs. What does this tell us? Well, for one, in terms of a study about hypertrophy, we know that it’s likely that of all the guys that could have been in this study, these guys were in the demographic of men most likely to build muscle. So, from a sample selection point of view, this is a trial designed to succeed (which isn’t some underhanded thing, since ALL trials should be designed to succeed).
Here’s the conclusion:
The Bottom Line: When it comes to hypertrophy, it’s pretty unlikely that resting 2 minutes or resting less than two minutes has much of an effect on how fast or big your muscles get. Resting for less time may make your workouts shorter though. Mostly, though I wanted to review this study because it just goes to show that it’s NOT impossible to measure hypertrophy directly.
Bryan goes into far more depth here.
My own reaction is curiosity of exactly what exercises were used, as rest periods are largely contingent on what you are doing. Do biceps curls and you don’t need much rest. Do tire flips and you fall over for 5 minutes, puke for 10, slowly sip water for another 5 minutes while sobbing sweet man-tears, and then crawl your way back for another set. Exercises matter.
They tested 1RM on the bench and squats at both the beginning and the end, so I am assuming that they used those exercises in the routine … but you know what happens when you’re assuming? You make an ass out of you and “uming”!