Review of 22 studies in long-distance runners
Strength and running economy
Heavy strength training improved running economy by a small amount (g = −0.32; 95% confidence interval: −0.55 to −0.10). Jump training had an uncertain effect (g = −0.13; 95% confidence interval: −0.47 to 0.21). Effects were larger after 10–14 weeks (g = −0.45) and with weights at 90% or more of a person's maximum for 1 repetition (g = −0.31).
What this does not show
The studies used gym exercises. They did not test Coach’s 3-exercise, 20-min home routine or establish 2 sessions per week as the best dose.
Review of 9 studies in 1,904 runners
Strength and running injuries
The review found no significant overall drop in injury risk or injury rate. An extra analysis of 3 supervised studies found lower injury risk (p < .001).
What this does not show
Seven studies had low quality. Supervised groups attended at least 88% of sessions. Most unsupervised groups attended 47–72%. This result does not show that supervision caused fewer injuries.
Meta-analysis across sports
Strength and sports injuries
A 2014 review of 25 trials and 26,610 people found lower injury risk with strength training (relative risk: 0.315; 95% confidence interval: 0.207–0.480).
What this does not show
A 2018 review found a similar result (relative risk: 0.338; 95% confidence interval: 0.238–0.480) in 6 studies with 7,738 people aged 12–40. Five studies covered soccer and 1 covered military training. These reviews do not establish the same effect for runners.
Coach