Progressive resistance is a foundational principle of building muscle. It’s a principle I have said is the most important key to growth for many years. Using the simplest of logic, if progressive resistance is the key to growth, then pushing the resistance as high as possible should produce the greatest gains. Not surprisingly, many lifters will sometimes train using their one-rep max (1RM) in hopes of breaking through plateaus. But is there any real science behind this practice? In fact, there is and it may just change the way you train.
A recent study in the Scandinavian Journal of Medicine & Science in Sports compared two different set and rep schemes. It wanted to know if single-rep sets using your 1RM had the same effect on anabolic signaling pathways as traditional higher-rep sets. In order to do this, they performed a crossover experiment using two different training protocols. A crossover design is one in which the subjects receive one treatment, then rest for several days or weeks (i.e., the wash-out period) and then receive the other treatment for comparison. In this instance, the subjects were divided into two groups. One group did leg presses using their 1RM for 15 sets. The other group trained using their 10RM for five sets. Both groups then did no training for seven days and then switched routines.
Muscle biopsies were taken from the quads (vastus lateralis) before and 30 minutes after each workout. A biopsy allows researchers to measure what signaling pathways were activated in the muscle after a workout. They saw that those pathways associated with muscle hypertrophy were activated to a significantly greater extent after the more traditional 10RM training than after the 1RM sets.
The results of this study are in line with that of previous studies. In general, the rate of hypertrophy in previous studies was greatest when the loads were 65%–85% of one’s 1RM. However it should be mentioned here that there is evidence that over time the differences between low-rep (90% 1RM) training and higher-rep (60% 1RM) training are minimal, at least in untrained subjects.
The take-home message is that singles are not as effective at triggering growth as higher-rep sets. That doesn’t mean they don’t have their place, particularly when you are training specifically for strength. But for mass, stick to 65%-85% of your 1RM for most sets.
References: J.J.Hulmietal.,ScandJMedSciSports.,22(2):240–8,2012; M.Wernbometal., SportsMed., 37(3):225–64,2007; V. Kumar V et al., J Physiol., 587(Pt. 1): 211–17, 2009.