16/06/2026
🏋️ Will strength training make you slower?
It's a common concern I hear from runners.
The fear comes from something called the interference effect — the idea that endurance training and strength training compete with one another and limit adaptations.
This concern largely stems from a landmark study published in 1980 by Hickson, which found that combining endurance and strength training reduced strength gains compared with strength training alone.
But research has evolved considerably since then.
A 2024 meta-analysis reviewing 59 studies and 1,346 participants found:
✅ No meaningful reduction in VO₂max adaptations
✅ No interference effect observed in females
⚠️ Small reductions in lower-body strength gains in males
For most runners, the question probably isn't:
❓ "Will strength training ruin my running?"
It's:
❓ "How do I integrate strength training into my running program effectively?"
Common mistakes include:
❌ Doing too much gym work
❌ Lifting heavy immediately before key run sessions
❌ Not allowing enough recovery
❌ Trying to improve everything at once
The goal isn't to become a powerlifter.
The goal is to become a better runner.
And for most runners, the potential benefits of strength training are likely to outweigh any small interference effects.
🎙️ This was one of the topics discussed with Kate Baldwin on The Rehab Runway podcast: Strength Training for Runners: What Actually Matters?
👇 Have you ever worried that strength training might negatively affect your running?
📚 References
Huiberts S, Bartolomei S, Vitale JA, et al. Concurrent training in endurance athletes: A systematic review and meta-analysis. Sports Medicine. 2024.
Hickson RC. Interference of strength development by simultaneously training for strength and endurance. European Journal of Applied Physiology. 1980;45(2-3):255-263.
Blagrove RC, Howatson G, Hayes PR. Effects of strength training on the physiological determinants of middle- and long-distance running performance: A systematic review. Sports Medicine. 2018;48(5):1117-1149.
