Better running economy (think fuel economy in a car) has gained a lot of attention over the past decade as a good predictor of performance in runners (1). It is well known that concurrent strength training will significantly help running economy whether we are talking about masters runners (2), well trained runners (syst. rev. and meta analysis 1), or high school runners (3). Strength training improves running economy whether you add it to the regular running program (4, 5) or even replace some of the running time with strength training (3, 6). Studies show that working out with heavy weights and low reps results in more improvement in running economy compared to explosive training (7) or using lighter weights with higher reps (8).
I think that’s all cool, but as a clinician, I want to know about injuries. Can strength training prevent injuries or reduce pain in runners? Well, that’s a great question, but we have no DIRECT data on that. However, I think I can make a strong argument that it can if you permit me to use my imagination a bit and infer from other studies…
- In runners already suffering from patellofemoral (knee) pain, strengthening the hips significantly reduces pain. (9, 10, 11). This makes sense, since runners with patellofemoral pain (PFPS) tend to have weaker hips (12, 13). Although, if we’re being honest, these are studies with runners who ALREADY have PFPS. Other research suggests that there isn’t much of an association in the causative nature of weak hips and PFPS (14). In other words, those with weak hips aren’t at risk of developing PFPS later and weak hips may be the result of PFPS, not the cause of it.
- If we get away from runners for a moment, we know that in other sports, strength training can reduce sports injuries by 1/3 and overuse injuries by 50% (15). That was in a study that looked at 25 other studies and over 26,000 athletes. However, no just “plain runners” were included, because there aren’t any studies looking at this topic in runners (to my knowledge). It’s estimated that 60% of running injuries are due to training errors, which are “overuse” injuries, so I think we can apply some biological plausibility (aka logic) here.
- Hamstring injuries in soccer players can be significantly reduced (prevented) by doing hamstring strengthening exercises (16, 17, 18). We can take a peek into runners when we look at a study (19) that compared sprinters with a recent hamstring injury vs. healthy sprinters and those who had suffered a hamstring injury within one or two seasons of the study. The researchers found that those with a history of hamstring strains had weaker hamstrings than the uninjured group, but again, correlation doesn’t equal causation. In other words, were they weaker because they were previously injured or was the weakness the causative factor behind the original injury? We don’t know.
- Runners with achilles problems respond well to strength training. They get back to running quicker than those who rest and use NSAID’s and orthotics (20)
- Lower calf strength (21) and calf muscle endurance (22) is found in runners with a history of a tibial stress fractures or shin splints respectively, but again, that is looking at runners who already had the condition. One study did look prospectively at runners and found that those with smaller calf girth were at higher risk of eventually suffering from shin splints (23)
In summary, I think it’s safe to say that we have enough data to say that strength training can help performance in many runners. As usual though, we have to say, “it depends.” If you’re already a powerlifter or bodybuilder and you start running, will strength training help you more? Doubtful.
It’s not as easy to say that strength training can reduce injuries, but I think we can be pretty safe in assuming it can help reduce injuries by inferring from other sports. We can also look at it from the perspective that since strength training will help with performance, most runners should be implementing strength training anyway, so if it reduces injuries, that’s just icing on the cake.