If you ask most runners why they do strength work, the answer is usually injury prevention. That’s understandable, it’s the framing that’s been around the longest and the one that gets repeated most often in running media. But when you look at the research as a whole, injury prevention might actually be the weaker argument for lifting, not the stronger one.
The case that’s been made for years rests largely on two meta-analyses by the same Danish research group. The first, published by Lauersen and colleagues in 2014, pooled 25 randomized trials and over 26,000 athletes and found that strength training reduced injury risk to less than a third of what it was in control groups, a far larger effect than balance work, stretching, or combination programs. A follow-up in 2018 by the same lead author narrowed the focus specifically to strength training and found a similarly strong protective effect along with something new: a dose-response relationship. More strength training volume meant more protection, with roughly a four percentage point drop in injury risk for every 10% increase in training volume. Together, these two papers are the foundation of a huge amount of “lift heavy, stay healthy” advice, and they’re often cited as a pair, sometimes described as the two studies that settled the matter.
Injury risk by exposure type
Cluster-adjusted risk ratio — Lauersen et al. 2014
The catch is that most of the athletes in both papers weren’t distance runners. They were soccer players, handball players, basketball players, and military recruits, populations training within a structured team environment where a coach was usually overseeing the work. When researchers went looking specifically at endurance runners, the picture got murkier. A 2024 review by Wu and colleagues (9 trials and about 1,900 runners) found that exercise-based interventions as a group did not significantly reduce running-related injury risk overall. The one exception was programs that were supervised, where someone was actually planning the progression and/or overseeing the workout. Unsupervised or unstructured strength work, the kind many runners do on their own, didn’t show the same benefit.
So the injury prevention story for runners specifically is less settled than the Lauersen papers alone would suggest, not because those papers are flawed, they’re well-regarded and methodologically solid, but because the populations they studied don’t map cleanly onto a distance runner’s training context.
It’s worth being clear about what strength training is actually expected to change in a runner, because the answer isn’t “everything.” A 2024 analysis of the broader determinants of distance running performance showed that strength training had little or no impact on measures like VO2max, the velocity at VO2max, maximum metabolic steady state, and sprint capacity. The benefit shows up specifically in running economy and time trial performance, not changes in the underlying aerobic engine itself.
What strength training changes — and what it doesn’t
Performance determinants — Llanos-Lagos et al. 2024
Running economy is a very important variable and this is where the evidence for strength training for runners is genuinely strong. A 2017 meta-analysis by Denadai and colleagues found that both plyometric training and heavy-load strength training improve running economy in endurance athletes. A larger 2024 meta-analysis by Llanos-Lagos and colleagues, pooling 31 studies and over 650 middle- and long-distance runners, confirmed this and went further, finding that high load training, plyometric training, and combined approaches all produced measurable improvements in running economy, with combined methods showing the largest effect.
One of the trials behind the pooled results above gives a good sense of what this looks like in practice. Støren and colleagues had well-trained distance runners add heavy half-squats, four sets of four repetitions, three times a week for eight weeks, on top of their normal running. After eight weeks, running economy improved by 5%, meaning the same pace cost noticeably less oxygen, and time to exhaustion at maximal aerobic speed increased by over 20%. VO2 max itself didn’t change. This is the pattern the larger pooled analyses keep finding: strength training doesn’t make your aerobic engine bigger, it makes you better at using the engine you’ve already got.
What 8 weeks of strength training changed
Percent change, pre to post — Støren et al. 2008
A better running economy means you use less oxygen at a given pace, which matters for every distance you’ll tackle as a runner. Unlike the injury prevention claim for runners, this one doesn’t come with a “but the population doesn’t quite match” asterisk. A 5% improvement in running economy doesn’t translate to a full 5% off your race time, the relationship between oxygen cost and pace flattens out somewhat at faster speeds, but the carryover is still substantial: for a 3:00 marathoner, something in the range of 4% would mean roughly 7 minutes, down to around 2:53, and for a 40-minute 10k runner it’s in the order of a minute and a half, down to around 38:30. Individual responses vary, and not everyone will see the full 5% economy gain Støren’s runners did, but even a fraction of that is a meaningful chunk of time for eight weeks of squats.
The main takeaway is that strength training is worth your time because it makes you a more efficient runner. That benefit is well supported by research done on runners themselves. The injury prevention benefit is probably real too, the broader evidence base from Lauersen 2014 and 2018 is too strong to dismiss, but for runners specifically it appears to depend a lot on whether the program is well coached and consistently progressed rather than just present, which is exactly what Wu’s 2024 findings point to.
Practically, this changes very little about what we actually do at Speedfarm. We’ve always built strength sessions into the schedule rather than handing them out as optional extras, partly because that’s the only way to capture the injury benefit if Wu’s findings hold, and partly because a properly progressed program is also what gets you the economy gains. But it does change how I’d explain the why to anyone asking. If you’re lifting twice a week and wondering whether it’s “working,” don’t just watch for injuries that didn’t happen. Watch for signs that your economy and aerobic efficiency are improving. That’s where the clearest evidence says the benefit shows up.
Lauersen JB, Bertelsen DM, Andersen LB. The effectiveness of exercise interventions to prevent sports injuries: a systematic review and meta-analysis of randomised controlled trials. Br J Sports Med 2014;48:871–877.
Lauersen JB, Andersen TE, Andersen LB. Strength training as superior, dose-dependent and safe prevention of acute and overuse sports injuries: a systematic review, qualitative analysis and meta-analysis. Br J Sports Med 2018;52(24):1557–1563.
Wu H, Brooke-Wavell K, Fong DTP, Paquette MR, Blagrove RC. Do exercise-based prevention programs reduce injury in endurance runners? A systematic review and meta-analysis. Sports Med 2024.
Denadai BS, de Aguiar RA, de Lima LCR, et al. Explosive training and heavy weight training are effective for improving running economy in endurance athletes: a systematic review and meta-analysis. Sports Med 2017;47:545–554.
Llanos-Lagos C, Ramirez-Campillo R, Moran J, Sáez de Villarreal E. Effect of strength training programs in middle- and long-distance runners’ economy at different running speeds: a systematic review with meta-analysis. Sports Med 2024;54:895–932.
Støren Ø, Helgerud J, Støa EM, Hoff J. Maximal strength training improves running economy in distance runners. Med Sci Sports Exerc 2008;40(6):1087–1092.
Kipp S, Kram R, Hoogkamer W. Extrapolating metabolic savings in running: implications for performance predictions. Front Physiol 2019;10:79.