What the Evidence Actually Says
The strongest evidence for runner strength training is on injury prevention. A widely cited meta-analysis of randomized controlled trials covering more than 26,000 athletes and thousands of injuries found that strength training reduced sports injuries to less than a third of their baseline rate, with overuse injuries specifically reduced by almost half -- a larger protective effect than stretching or proprioception training showed in the same analysis[1]. For a training block built around steadily accumulating running volume, that's a direct answer to the injury risk that volume itself creates.
The evidence on performance is more specific but still real: a systematic review and meta-analysis of strength training studies in middle- and long-distance runners found that high-load resistance training and combined training methods produced measurable improvements in running economy -- how much energy a runner burns to hold a given pace -- while plyometric training improved economy specifically at slower running speeds; lighter, submaximal-load training showed no meaningful benefit[2]. The takeaway isn't that any strength work helps -- it's that the type of strength work matters.
The Movement Patterns That Matter Most
For runners, a handful of movement patterns do most of the useful work: squats and step-ups build the hip and quad strength that absorbs impact on every stride, single-leg exercises like split squats and single-leg deadlifts address the fact that running is fundamentally a one-leg-at-a-time activity that two-legged lifts don't fully train, and hip and glute work targets the stabilizing muscles that keep the pelvis level and prevent the kind of side-to-side wobble that wastes energy and stresses joints over long distances.
Calf raises and short plyometric drills -- low hops, bounds, skips -- round out a runner-specific program: they build the lower-leg and tendon resilience that absorbs repeated ground-contact forces, and the research above specifically linked plyometric-style training to running-economy gains. None of this requires a full bodybuilding split with isolated arm or chest work -- a runner's strength program can be short and still cover what actually transfers to running.
Fitting Two Sessions a Week Around Marathon Training
Two sessions a week is enough to capture most of the benefit shown in the research above, and it's a volume that fits realistically around a marathon training schedule without adding excessive fatigue. The best placement is usually on or right after an easy running day, or immediately following a hard running session rather than the day before one -- lifting heavy the day before a key workout or long run risks showing up to that run with tired, less responsive legs.
As marathon-specific training builds toward its heaviest weeks, most runners are better served scaling strength sessions down -- fewer sets, lighter loads, shorter sessions -- rather than dropping them entirely, since the injury-protective effect depends on staying consistent through the block, not on lifting maximally close to race day.
What to Skip
A running-focused strength program doesn't need high-volume hypertrophy work, isolated single-muscle machines, or a bodybuilding-style split across different muscle groups on different days -- none of that reflects what the research above actually tested, and extra volume for its own sake adds fatigue without a matching return for a runner's specific goals.
It's also worth avoiding true one-rep-max attempts and scheduling strength sessions too close to hard running workouts -- a session that leaves legs deeply sore going into a key interval session or long run undermines the very running training the strength work is supposed to be supporting.