I was giving a talk on running science at Radford University in America last week, and someone asked for my opinion on the age-old question of whether lifting weights helps you run faster. I offered my standard answer to all tricky questions (“Uh… it depends.”), because there’s really not a lot of solid evidence either way.
That’s why I’m happy to see a new meta-analysis that brings together the evidence on one particular aspect of this question: the relationship between strength training and running economy, which is the measure of how much energy you burn to run at a given pace. I’ve written before about evidence that strength training does indeed improve running economy (for example here and here), but you get a much clearer picture by systematically assessing all the available evidence rather than looking at individual studies.
The meta-analysis, published in the Journal of Strength and Conditioning Research, comes from researchers in Spain and Greece (including Jordan Santos-Concejero, whose running research has featured in several previous posts). They sifted through hundreds of studies to find those fulfilling several specific criteria:
The subjects had to be competitive middle- or long-distance runners;
They had to have a VO2 max of at least 60 mL/kg/min, which indicates a high level of training and ability;
The studies were peer-reviewed and included a control group doing no strength training for comparison;
The strength training program had to be at least four weeks long; and
Running economy had to be measured before and after the strength training period.
They ended up with five studies meeting those standards, with a total of 93 competitive runners. And the pooled results were impressive: a “large, beneficial effect” of strength training on running economy, corresponding to an average improvement of 2.32 mL/kg/min in running economy. After strength training, in other words, the runners could maintain the same pace while using 3-4 percent less oxygen.
What were the characteristics of the strength training programs in these five studies? They were fairly diverse, but all lasted between 8 and 12 weeks, and included two to three sessions per week (on top of the six to nine running sessions the subjects were already doing).
None of the studies involved lifting to failure; in fact, four of them used “low to moderate” loads of 40-70 per cent of one-rep max. The volume was relatively low, with two to four different exercises plus plyometric jumps (up to 200) and short sprints.
So does this provide the final answer about whether runners should lift weights? It’s still not quite that simple.
At the very elite end of the spectrum, if you’re already running as much as your body can take, it does seem like a no-brainer—though, as the study authors note, one survey of 2008 U.S. Olympic Marathon Trials competitors found that nearly half did no strength training at all, and most of the others didn’t do much.
For many of us, though, adding strength training may compete for time and energy with the possibility of simply running more—which itself can improve running economy as well as boost overall aerobic fitness. The real “control group” should involve adding extra running, rather than doing nothing during the strength training time.
Instead of focusing on running economy, the benefits of strength training for regular runners may have more to do with other factors like injury avoidance, where the evidence is once again skimpy and mixed at best. Overall health, especially with respect to age-related muscle loss, is also worth considering.
So can strength training make you faster? This study helps make the case that the answer is “Yes.” Does that mean adding strength training is the most effective change you can make to your training? For now, I’ll have to stick with “It depends.”