Long runs are essential for marathon
Progressive long runs are essential for marathon-distance preparation and cannot be substituted by shorter, higher-intensity sessions.
In plain English
Runs longer than about 90 minutes teach your body things shorter runs cannot. You learn to burn fuel for hours and keep your legs from breaking down. Marathon plans usually build the long run up to 2.5 to 3 hours or more.
Why it works
Prolonged sub-threshold running produces fuel-depletion adaptations, capillary growth, and connective-tissue conditioning specific to extended-duration efforts.
What it means in practice
When reviewing marathon plans, the long-run progression should peak at 2.5-3.5 hours regardless of runner pace. Plans capping the long run at 90 minutes or shorter for marathon prep should be flagged. For half-marathon, long runs of 90-120 minutes are sufficient.
The evidence
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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
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Resilience is a meaningful and trainable performance attribute distinct from VO2max, lactate threshold, or running economy at fresh state. Athletes matched for VO2max and 10K performance differ in their ability to preserve running economy during prolonged exercise. Specifically: runners who regularly practice long runs (>90 minutes) preserve running economy better — only 3.1% increase in oxygen cost over a 90-minute run at ~80% VO2max, versus 6.0% increase in less-accustomed runners. Higher overall training volumes, regular long runs, and strength training are all associated with better durability. Specificity matters: building resilience at race pace likely requires training regularly at race pace, including long aerobic intervals (e.g., 15 × 1000m as practiced by elite marathoners). Progressive long runs and race-pace efforts within long runs may further enhance resilience, though specific RCT evidence is still developing.
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Kenyans accumulated significantly higher overall running distance (P<0.001, d≥1.35) than the Spanish groups. Within higher-intensity work, Kenyans completed substantially more tempo runs and short-interval training (P<0.001, d≥1.38), but did not complete more long intervals or races. Easy runs (a non-deliberate-practice activity) were the largest single training component for all groups as a proportion of overall running distance. Few differences emerged between European-standard and national-standard Spanish runners except in easy-run volume — emphasizing both the value of easy running and the necessity of higher-intensity training to compete at world-class levels. There was no evidence that starting systematic training at younger ages was advantageous.
n=55
Why we call confidence high
Toresdahl 2023 NYC marathon training data found that longer training runs were associated with lower race-day injury risk. Jones 2025 resilience framework explains the physiological why. Casado 2019 documents long-run prevalence in elite training.
Where it applies
Adult marathon and ultramarathon runners; less critical for half-marathon and shorter.
Does not apply to: 5K and 10K specialists where long-run benefit is more limited.
Plans that respect this
Plans that scored well on the rubric measures informed by this claim.
- 10-Week Run Your First 10k (3 days)
- 10-Week Run Your First 10k (4 days)
- 10-Week Run Your First Half Marathon (3 days)
- 10-Week Run Your First Half Marathon (4 days)
- 10-Week Sub-1:30 Half Marathon (4 days)
- 10-Week Sub-1:30 Half Marathon (5 days)
- 10-Week Sub-1:30 Half Marathon (6 days)
- 10-Week Sub-1:45 Half Marathon (4 days)
- 10-Week Sub-1:45 Half Marathon (5 days)
- 10-Week Sub-1:45 Half Marathon (6 days)
- 10-Week Sub-2 Half Marathon (3 days)
- 10-Week Sub-2 Half Marathon (4 days)
Last reviewed 2026-05-01. See how we score.