As we discussed in a former article, muscular hypertrophy or any other desirable muscular adaptation depends on the principle of progressive overload. Simply put – we must add more stress over time in order to force our bodies to adapt and thus change (via performance or physically) the way we want them to. One of the many ways we can progressively overload our muscles is through training volume, which can be calculated by multiplying weight x sets x reps. Altering any one of these components will impact total volume, either increasing or decreasing it.
Many studies have successfully demonstrated the importance of total training volume for muscular hypertrophy, rather than the specific details within those training protocols (one of which being repetition schemes). The study to be discussed is one of the first of its kind to put the specific rep range claims to rest. Schoenfeld and colleagues do this by using the standard training practices of powerlifters and bodybuilders (low and high repetition ranges, respectively) and comparing the two. What better way to test high and low repetition ranges than through the two athlete populations well-known for using them?
To really put repetition ranges to the test, Schoenfeld and colleagues used a randomized parallel design in order to compare differences between powerlifting- and bodybuilding-type resistance training regimens. What this design means is that the subjects, which were 20 male experienced lifters, were pair-matched based on their baseline strength upon entering the study. Once matched, they were randomly assigned to one of the two training interventions.
The two groups being used were a strength-type resistance training routine (ST) and a hypertrophy-type resistance training routine (HT). The focus of the strength group was to induce high amounts of mechanical tension, while the hypertrophy group’s focus was to induce a high amount of metabolic stress. Both mechanical tension and metabolic stress are two of the three well-known components important in promoting muscle growth (the third being muscle damage).
Some quick background
Mechanical tension can be described as the tension being placed on the working muscle group at any point in its full range of motion (passively through stretching the muscle, or actively during the contraction phase). Metabolic stress on the other hand is culmination of the burning sensation or “muscle pump” you feel in the targeted muscle group (think of what’s happening on the physiological level – blood pooling, lactate buildup, etc.).
The main difference between these two training styles is how the training sessions are structured. First and foremost, the strength and hypertrophy groups performed the same exercises over the course of the 8-week training period, consisting of 3 sessions per week. Both groups performed each set to muscular failure as well, which is defined as being unable to perform another repetition with proper form.
The hypertrophy group was given a split routine, or a typical bodybuilding split, where each session focused on a particular muscle group. HT subjects performed each set at moderate repetition ranges (8-12) and loads were adjusted accordingly to ensure working sets were achieving muscular exhaustion.
The strength-focused group was given a total-body routine, where 1 exercise was performed per muscle group in every session. A big difference here would mean that the ST group often hit more than 1 major muscle group at once. ST subjects performed training sessions in a low repetition range of 2-4 reps per set. Just as in the HT group, loads were adjusted as needed in order to ensure the working sets achieved muscular exhaustion.
As stated earlier, total working volume was equated between the two training groups and after the 8-week period there were no significant differences in total volume load used. An interesting observation about the training sessions, however, was that the hypertrophy training group had a much shorter training session on average compared to the strength group. The average time spent training for a HT subject was about 17 minutes, while the average time for an ST subject was approximately 70 minutes.
Regarding changes in muscle mass, both training groups experienced significant gains in muscle thickness during the 8 weeks of training. As for the extent of these hypertrophic changes (after adjusting for baseline value), there were no differences between the ST and HT interventions noted. This is quite a substantial finding as it shows us how both the application of high and low rep schemes can produce similar hypertrophic responses. Especially with such a stark difference in training time of both groups we can see that training with intention and effectively working the target muscles in each set does not fail to produce the results we want, regardless of the length of time spent in the gym.
Now strength is an interesting variable here as both the HT and ST groups experienced significant changes. It should be noted that once this marker was adjusted for baseline values, researchers found the magnitude of these strength gains to favor the ST group more so than the HT group. While the key finding from this paper lies within the hypertrophic adaptions seen in both ST and HT groups, this strength measure is an interesting take home point for a later discussion on strength training and training specificity as a whole.
This is quite a novel study that utilizes two well-known training protocols from bodybuilders and powerlifters in order to compare and observe their respective muscular adaptations. Granted that the athlete accounts for volume in each training session, it is clear that both high and low repetitions can be employed in order to gain muscle mass over time. Strength-focused athletes, however, will still benefit more from working with lower rep ranges compared to moderate/high, as strength sport proves to require more specified training protocols (via practicing those heavier lifts). A bodybuilding-style split can definitely save some time as well, but both methods are equally efficient once we pay attention to the total volume of work being performed. Of course, as with any big topic, there is always more research to be done in this area, especially where well-trained athletes are involved!
Schoenfeld, B.J., Ratamess, N.A., Peterson, M.D., et al. Effects of different volume-equated resistance training loading strategies on muscular adaptations in well-trained men. Journal of Strength and Conditioning Research. 2014: 28(10); 2909-2918.
Written By Gillian SanFillipp