A half marathon first protects new marathoners
Medium confidence
First-time marathoners who had already raced a half marathon got hurt about 60 percent less during training than those who had not. The finding comes from a single strong cohort of New York City Marathon runners, so read it as a solid lead rather than a settled rule.
Why it works
Training for a half raises how much you run week to week and toughens the legs and joints, so the marathon block has something to build on. Jumping straight from short runs into marathon training crams all of that adjusting into too few weeks.
What it means in practice
For a first-time marathoner, point them toward training for and racing a half before the marathon block begins. A plan that skips that step deserves a caution flag when the runner is facing their first big jump in distance.
The evidence
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Of 675 first-time marathoners who finished the study, 64 (9.5%) sustained a major injury that stopped a race start or finish; another 332 (49.2%) reported a minor injury affecting training or performance. Prior half-marathon experience predicted lower injury risk (multivariable OR 0.40, 95% CI 0.22-0.76, p=0.005), as did longer training runs (OR 0.87 per unit, 95% CI 0.81-0.94, p<0.001). Running four or more times a week carried higher risk than fewer sessions (RR 1.36, 95% CI 1.13-1.63, p=0.001), while age and sex made no significant difference. Injuries were self-reported, so treat the effect sizes as suggestive rather than definitive.
n=720
Why we call confidence medium
Toresdahl 2021 studied NYC Marathon runners and found half-marathon experience linked to an odds ratio of 0.40 for training injury. It is one high-quality cohort study, and the direction fits how the body builds up over time, so the case is plausible but not yet replicated.
Where it applies
First-time marathoners.
Does not apply to: experienced marathoners adding distance.
Last reviewed Apr 30, 2026. See how we score.