Key takeaways
Heavy half-squats three times a week for eight weeks improved running economy by about 5% in well-trained runners
Strength training does not raise VO2max, but it makes each stride cost less oxygen
Lift twice a week, heavy with few reps, on hard days, and leave about 48 hours before your next key run
Lifting heavy won't raise your VO2max. It will do something almost as valuable: make each stride cost less oxygen, so you run faster at the same effort.
The research
- Støren et al., 2008: well-trained distance runners added heavy half-squats (4 sets of 4 reps, near maximal load) three times a week for eight weeks. Running economy improved by about 5% and time to exhaustion at their maximal aerobic speed rose substantially — without weight gain and without a change in VO2max.
- Rønnestad and Mujika, 2014 reviewed the evidence for runners and cyclists: heavy and explosive strength training improves economy and performance in endurance athletes, especially when it's heavy, specific and maintained during the season.
Why it works: stronger, stiffer muscles and tendons store and return more elastic energy, and each stride uses a smaller share of your maximum force. Remember the three parts of performance: VO2max, threshold and economy — see what limits VO2max.
What to do
Twice a week, 30–45 minutes:
| Exercise | Sets × reps |
|---|---|
| Back squat or half squat | 3–4 × 4–6, heavy |
| Romanian deadlift or hip thrust | 3 × 6–8 |
| Single-leg work (split squat, step-up) | 3 × 6–8 per leg |
| Calf raises (straight and bent knee) | 3 × 10–15, slow |
| Plyometrics (pogo jumps, bounds, box jumps) | 3 × 6–10, quick contacts |
| Core (plank variations, carries) | 2–3 sets |
Lift heavy with good form and few reps; you are training force, not muscle soreness.
Fitting it in
- Put strength on hard days (after intervals, or later the same day) so easy days stay easy.
- Leave about 48 hours between heavy legs and your next key run, especially intervals — heavy legs make the 4×4 feel much harder.
- In race weeks, keep a short, lighter session to maintain.
Body weight
Heavy, low-rep strength work causes little weight gain when you run a lot. If you do gain muscle, it can lower relative VO2max slightly (VO2max and body weight) — worth it in mixed sports such as Hyrox.
Frequently asked questions
Does strength training improve running?
Yes. In one study, well-trained runners who added heavy half-squats for eight weeks improved running economy by about 5% and lasted much longer at their maximal aerobic speed, without gaining weight or changing VO2max.
How often should runners do strength training?
Twice a week, for 30 to 45 minutes, focused on heavy squats, deadlifts, single-leg work, calf raises and plyometrics. In race weeks, a short lighter session is enough to maintain.
Should runners lift weights on easy or hard days?
On hard days, after intervals or later the same day, so your easy days stay easy. Leave about 48 hours between heavy leg work and your next key run.
Sources
- Støren Ø, et al. Maximal strength training improves running economy in distance runners. Med Sci Sports Exerc, 2008.
- Rønnestad BR, Mujika I. Optimizing strength training for running and cycling endurance performance: a review. Scand J Med Sci Sports, 2014.