Prior half-marathon racing experience is associated with lower injury risk and better outcomes during marathon training.

In plain English

First-time marathoners who had already raced a half marathon got hurt about 60 percent less during training than those who had not.

Why it works

Half-marathon training builds the chronic load and tissue capacity needed to handle marathon training. Going directly from short-distance running to marathon training compresses adaptation into too short a window.

What it means in practice

When advising someone targeting their first marathon, suggest building through a half-marathon first (training for and racing one) before starting marathon-specific training. Plans that skip this step warrant a caution flag for runners under their first big distance jump.

The evidence

• Toresdahl, B.G., McElheny, K., Metzl, J. et al. (2021). Factors associated with injuries in first-time marathon runners from the New York City marathon. Physician and Sportsmedicine.

  Among 675 completers: 64 (9.5%) sustained major injuries preventing race start or finish; an additional 332 (49.2%) had minor injuries affecting training or performance. Several risk factors emerged. (1) Prior half-marathon experience was protective — runners who had completed a half-marathon before the study were less likely to be injured (multivariable OR 0.40, 95% CI 0.22-0.76, p=0.005). (2) Higher training frequency was associated with injury — averaging ≥4 runs per week was associated with greater injury risk than <4 runs per week (RR 1.36, 95% CI 1.13-1.63, p=0.001). (3) Longer training-run distance was associated with lower race-day injury risk (OR 0.87 per unit increase, 95% CI 0.81-0.94, p<0.001). (4) Injury incidence did not differ significantly by age or sex. The combined picture: novice marathoners benefit from prior race experience, fewer-but-longer training runs, and at least one substantial long run.

  n=720

Why we call confidence medium

Toresdahl 2021 NYC marathon study found half-marathon experience associated with OR=0.40 for training injury. Single high-quality cohort; direction is plausible mechanistically.

Where it applies

First-time marathoners.

Does not apply to: experienced marathoners adding distance.

Related claims

• Long runs are essential for marathon