My lab dabbles in mTOR work so I pretty regularly scan pubmed for new papers with mTOR in the title or abstract. Its a fast moving field so there’s lots to keep up with and usually 20-30 new papers out for each of my saturday morning mTOR searches. This morning I stumbled upon this little gem:
Burd et al., PLoS One Low-load high volume resistance exercise stimulates muscle protein synthesis more than high-load low volume resistance exercise in young men.
Now, I’m no exercise physiologist so I’m not going to go into details on the background of the work but I do know enough to know that stimulating protein synthesis in muscles through weight training is your goal. This builds muscle mass, makes you stronger/faster — all those reasons that we go to the gym in the first place. The question is how best to do that. mTOR, for those that don’t know, is a kinase involved in regulating protein synthesis. Its a complicated cascade but the basics are that stimulating mTOR in a cell type leads to more protein synthesis. If a specific type of exercise stimulates mTOR activity, this is probably a good thing to achieving results from your workout. In the paper they had young men do three types of exercise (on a leg extension machine): 1) low rep / high weight, 2) medium rep / medium weight and 3) low weight / high rep. In a nutshell, they found that low weight / high rep was the best way to go to stimulate mTOR in muscle fibers. So what does this mean?
Before that let’s have a bit of background on my relationship to the weight room. I’m a gym rat. I became one sometime in junior high and the major reason was football. To play football you have to build muscle, plain and simple. At first the gym and I didn’t get along very well but I soon started to see that weight room work led to immediate advantages on the field and I was hooked. Now, 20+ years later, my football days are long gone but I still try to make it to the gym at least 5 days a week. The gym does several things for me. Most importantly, it keeps me fitting into my clothes. I have always struggled with my weight and without the gym bad things happen to my waistline very quickly. The other major thing the gym gives me is stress relief. I am a big proponent of having an outlet for stress and the gym has always been were I go for release. Finally, maintaining some level of strength and fitness is obviously important for health but for me its more about being able to keep up on the basketball court. With my bad back and arthritic knee (just some of football’s many long-lasting gifts) the gym is key for keeping my strength up to be able to look halfway competent on the basketball court.
While I have never put myself into the bodybuilding category, being in the gym all the time exposes you to many of these people and I have long been aware of the various debates on how to best design a workout to build muscle. Most of the people who think of themselves as builders have some idiotic workout routine where they put on all the weight they can handle, strut around for awhile and then do a set with terrible form while screaming at the top of their lungs. Generally speaking, these people end up with an injury a few months later and you never see them again. Serious builders, in my experience, rarely do this and have quite a bit of variation to their workouts. Sometimes they will do high weight with low reps and others very low weight with reps as high as 50/set. If you get in on their debates over which is best for building mass they generally fall on the side of high weight low reps for pure mass and low weight high reps for finer definition. I have tried both of these types of workouts from time to time but more often than not I fall into a pure maintenance category where I just go through the motions with medium weight and medium reps occasionally throwing in a day where I do high weight low reps. This has not always been true though as there was a time maybe three years ago where I exclusively did low weight and high reps for about three months. I saw some nice gains from this but eventually quit doing it because I was too tired all the time (not sleepy tired, I was literally having trouble pipetting because of muscle fatigue). I think this paper has just explained why.
Going back to the findings of the paper, the work essentially shows that high rep low weight exercise not only stimulates protein synthesis more than high weight low rep work but also stimulates it for a longer period of time. Again, I’m no exercise physiologist but I interpret this to mean that it takes a bit longer for you to recover after this type of weight training. As far as I can tell, the paper is only talking about a single trial with leg extensions so there are likely some caveats there but it is interesting nonetheless.
So how is this going to change my workout? Well, I’m going to go back to the low weight high rep strategy starting today but rather than my usual three day rotation of muscle groups I am going to extend it into a four day rotation (maybe five if the fatigue thing starts to kick in again). I actually like the idea of extending the rotation because this should give me more time for cardio (I’ve got a nice line of books to get to so this is perfect timing) and maybe an extra pilates session per week. Back in the day when I actually following the bodybuilding trends it was always interesting to see how current research was impacting what the builders in the gym were doing. While I doubt that this will have an immediate impact on what I see in the gym, if it makes it into any of the mags there might be some others switching up their routines around me. Of course, their low weight is my high weight so I guess I’ll have to be counting everyone’s reps.
Burd, N., West, D., Staples, A., Atherton, P., Baker, J., Moore, D., Holwerda, A., Parise, G., Rennie, M., Baker, S., & Phillips, S. (2010). Low-Load High Volume Resistance Exercise Stimulates Muscle Protein Synthesis More Than High-Load Low Volume Resistance Exercise in Young Men PLoS ONE, 5 (8) DOI: 10.1371/journal.pone.0012033