Time for another installment of the Study of the Week. This week's selection was a study I found while reading my first subscription of Strength and Conditioning Research. This is a service that is produced by Chris Beardsley and Bret Contreras that reviews around fifty studies in each edition. I highly recommend subscribing if you are interested in keeping up on the latest research. If your like me then you love getting all the great information, but I just don't have the time to sift through each scientific paper that is published. Now that I got my plug in it is time to move on to the actual study.
One of the most popular goals among trainees is muscular hypertrophy. I mean who doesn't want to get swull. Right? You never know when Megan Fox will coming knocking (but don't hold your breath on this one). Either way Megan Fox or no Megan Fox we all like to look good and look good naked. There isn't anything wrong with it.
We generally attribute the increase in muscle mass (i.e. hypertrophy) to three mechanisms: mechanical tension, muscle damage, and metabolic stress. Alwyn Cosgrove has championed these three factors in his training methodology. If you haven't read anything buy him stop by my recommended book list and pick up his new book The New Rules of Lifting: Supercharged. I just finished reading it. And let me say it was EPIC!
Any way back to the study, so in accordance with these three mechanisms we have made the decision that hypertrophy is best achieved with higher training volumes, specifically in a rep range of 8 to 12 reps.
What the researchers examined in this study is how different reductions in load affected the overall volume that could be completed for multiple sets of an exercise.
The researchers took 24 trained, young male subjects, all with the same maximal lower body strength (this was relevant because the exercise they used in the study was the leg press). The subjects completed an exercise weekly for five weeks. Researchers tested the ten rep max of each subject in the first week. Subjects were then required to complete a lower body test each week for each following week, which included test in which load was constant each set and then 3 test which the load was reduced by 5% each set, 10% each set, and 15% each set. The research then measured the total number of repetitions and the volume of weight lifted each workout.
Researchers found statistical significant difference in the number of repetitions performed in each workout routine. The 5% reduction routine resulted in fewer repetitions in each successive set, especially 2-4 and 3-4 when compared to the 10% and 15% reduction routines. Researchers also found a statistical significant difference in the total amount of weight lifted between each workout routine. Higher volume loads were achieved with each reduction in intensity, but when the load was reduced by 15% the subjects were capable of performing extra repetitions that took them out of the target rep range of 8-12 reps.
Due to these results the Researchers concluded that in order to maximize volume while maintaining the target rep range of 8-12 reps for hypertrophy the load must be reduced on each successive set by 10%, specifically when training to failure.
This study did have two limitations. One being that it only referred to routines that involved training to failure in multiple set protocols. Two it recorded routines that called for 1min rest between sets. It is possible that if the rest period was manipulated the results may be changed.
Implications for Training
This study is not groundbreaking by any means, but it does offer a possible training protocol for producing greater muscular hypertrophy. It would be worth performing a protocol in which you perform exercises in your training program for two months using the following training protocol: perform 4sets of 8-12 reps on each successive set reduce the training load by atleast 5% but not more than 10%. Maintain the same rep tempo throughout all your sets. Measure body circumference and body compositions at the beginning and end of both months. Then evaluate if there was any significant difference in circumferences and if body composition improved or remained the same. It is something I am definitely going to keep in mind for the future when I am writing my own programs.
NOW GET UP AND GO LIFT!
Planned Intensity Reduction to Maintain Repetitions Within Recommended Hypertrophy Range. by Medeiros Jr HS, Mello RS, Amorim MZ, Koch AJ, Machado M. International Journal Sports Physiology Performance. 2012 Nov 19
Strength and Conditioning Research by Chris Breadsley and Bret Contreras. January 2013.