“There seems to be a lot of debate about training heavy vs training 8-12 rep range for gaining size. What is your opinion?”
Lots of people want to build significant amounts of muscle, but there are a lot of different and conflicting bits of information around. For a beginner, this can be extremely confusing when it comes to finding a program to suit their goals. So if you want to build muscle, what sort of rep range should you be working in? High reps with relatively lighter weights, or heavier weights with relatively lower reps?
Traditional knowledge dictates that training in the lower rep range is good for building strength, while training within higher rep ranges is better for hypertrophy, or even muscular endurance. The reasoning for this is because strength is largely a function of the neurological system, and heavier weights do a better job in stimulating the nervous system (say 3 to 6 reps). Meanwhile, muscle size and hypertrophy is a product of time under tension, and training in the higher rep range (say 10 to 15 reps) is better at providing more time under tension. Everything in between can be considered somewhat of a hybrid rep range, and can help a little with both.
With the above information, is it therefore best to train within the 8 to 12 rep range, because it gives you the best of both worlds? The answer unfortunately is not as black and white as the above. If we consider some of the world’s biggest and best bodybuilders, we can almost guarantee that none of them will have an identical training program. For example, Ronnie Coleman is famous for his 1000 lb leg presses, whereas few other Olympia contestants would even dream of doing this, even if they were physically capable. Simply put, everyone is a little different and there is no single best program for everyone. Some people respond better to heavy weights, while others may respond best to high volume training.
What complicates this is that the available information in the scientific literature that compares different training methods is limited. Yes, there are studies and trials, but a major downfall in such publications is that the number of test subjects is very low. Well-designed pharmaceutical or even dietary supplement trials can involve hundreds of participants. However, exercise science trials are lucky to get around a dozen test subjects. What this means is that even the most reputable publications may struggle to find results that can be 100% true for the majority of the population.
Generally speaking, for the average person wanting to put on muscle, it is not a good idea to religiously follow the training programs of the elite pros. Instead, cycling between strength and hypertrophy programs is a good way to continually build muscle for the vast majority of people, ie periodisation. Once you have mastered training technique, starting off by building a solid foundation of strength is often a good idea. This means lifting heavy at a relatively low rep range for a couple of months. Doing this would make training at a higher volume and higher rep range a little easier further down the path.
One article we can take some advice from was published by a group of Brazilian scientists from the University of Sao Paulo (Monteiro et al, 2009). Their research suggested that the best way to get stronger was to train in a “nonlinear periodised” manner. In other words, every week, train within a different rep range each week. The subjects in the study did a four week rotation which consisted of 12-15 reps, 4-5 reps, 8-10 reps, then back to a high rep week, which also incorporates some low rep work.
In summary, there is no rep range that is definitively perfect for building muscle. Change things up, do a bit of everything. However, if you’re starting off, you may consider doing some strength work first. To learn more, check out our periodisation article.Monteiro et al (2009), Nonlinear periodization maximizes strength gains in split resistance training routines. J Strength Cond Res; 23(4):1321-6.