Strength Training for Runners: How Many Days a Week Actually Works
"Should I lift weights?" isn't really the question runners are stuck on anymore — most know they should. The question that actually trips people up is how often, and how to fit it around running without either skipping it or over-cooking your legs before a key session.
Source: Lauersen, Bertelsen & Andersen, meta-analysis, British Journal of Sports Medicine, 2014
Why frequency matters more than the workout itself
A single heavy gym session a week feels productive, but it mostly leaves you sore for your next two runs rather than building lasting strength. Tendons and muscles adapt to repeated moderate stimulus, not to one occasional shock. Two shorter sessions spaced across the week give your legs a chance to absorb the work, recover, and still turn up fresh for quality running days.
How many days a week should runners strength train?
- Two sessions a week is the sweet spot the injury-prevention evidence keeps landing on — enough stimulus to matter, not enough to compromise running.
- One session is better than nothing, but the injury-reduction effect is noticeably smaller.
- Three sessions can work for runners with lower weekly mileage or an off-season block, but most marathon-mileage runners find a third session starts eating into leg freshness for key runs.
A simple weekly split
Session 1 — early in the week
- Squats or split squats: 3 x 8–10
- Romanian deadlifts (or single-leg): 3 x 8–10
- Calf raises: 3 x 12–15
- Plank or dead bug: 3 x 30–45s
Session 2 — 3–4 days later
- Step-ups: 3 x 8 per leg
- Hip thrusts or glute bridges: 3 x 10–12
- Single-leg calf raises: 3 x 10–12
- Side plank: 2–3 x 30s per side
Both sessions take 25–35 minutes. Keep 1–2 reps in reserve on most sets — this is about durability, not maxing out.
Where to fit it around your running week
The least disruptive placement is straight after an easy run, or on a day that's otherwise a rest day. Avoid heavy lower-body strength the day before a long run or a hard interval session — 48 hours between heavy legs work and a key run gives you enough recovery that neither session compromises the other.
What if I can only manage one session a week?
Do it — one session still beats zero, and the evidence for load management and gradual build-up matters more than perfect strength frequency (see our injury prevention routine for a bodyweight-only version that needs no gym at all). But if injuries are a recurring problem, finding a second short slot is usually the single biggest lever you have left to pull.
If you're already putting in the gym time, it's also worth reading whether creatine is worth adding for runners — its clearest evidence is specifically for amplifying strength-training gains like these.
Frequently Asked Questions
Will strength training make me a slower runner?
No — done at a sensible volume, it improves running economy and durability rather than adding bulk that slows you down. The risk only appears with very high-volume bodybuilding-style programmes stacked on top of heavy mileage.
Can I strength train the day before a race?
No — stop heavy lower-body strength work at least 4–5 days before race day so your legs are fully recovered.
Do I need a gym, or can I do this at home?
Bodyweight and resistance-band versions of every exercise above work well; a gym just lets you add load faster once bodyweight gets easy.