Is light the new heavy?

The recent study that training at 30%-1RM promoted hypertrophy to a similar extent as 80%-1RM (1) has definitely generated some discussion, and I’ve written some of my initial thoughts on it in another post. If you haven’t read the original article, or my thoughts on it, definitely set aside some time if you’re interested in optimal hypertrophy training.

After getting my thoughts down, one point that came up in the comments is that for beginners in the gym the more reps they perform the better, in terms of optimizing technique. It’s hard to argue with this logic, and in reality I totally agree, nothing is better for perfecting technique than actually performing the reps (the gym equivalent of the 10000 hour rule).

My main concern with this strategy is that while light weights (let’s say 30%-1RM) are certainly able to provide a hypertrophic stimulus when used to failure (1), how does this influence technique? Is a bench press or squat at 30%1RM really the same exercise as at 80%-1RM or higher?

How does load affect form?

Awhile back I did a Strong Science post featuring a small collection of deadlift-related literature, ending with a popular comparison of the trap-bar and conventional bar deadlift (2). Other than the comparison of the two different bars, the best part of the study was a graph the authors produced tracking bar path for each lift across various training intensities (10-80%-1RM).

The intent of tracking bar path was to detect differences between the trap bar and standard olympic lifting bar, but by including different training intensities, the authors have clearly demonstrated that bar path is different across the 1RM continuum.

While specific to the deadlift, as bar load increased from 10-80%1RM, we can see vertical displacement (height of the lift) decreased, and there was a substantial difference in the horizontal path of the bar. These weren’t small differences either, as we can estimate differences as high as eight centimetres in the horizontal direction, and approximately 10 or more centimetres vertically from the graph above. I doubt the lifters became shorter to explain their now vertically challenged deadlifts at heavier weights, but rather these differences in bar path are reflective of altered technical performance of the lift, some of which I’ve discussed in other posts (here, here and here).

What’s optimal?

If one theme emerges from my latest training posts, it’s that there is no ONE optimal training load if you’re trying to maximize strength and hypertrophy while mastering exercise technique. Any training program should reflect a series of training intensities and not be pigeon-holed to one specific range of weights.

Strength, hypertrophy and exercise technique are optimally developed across the repetition maximum continuum, and training exclusively in one range will make choosing your weights easy, but you’ll compromise your progress in the gym. The best part is if you spend time warming up across the rep ranges on your way to your working weight, you’ve covered your bases without giving it much thought. No graphs required!