“Never increase your weekly mileage by more than 10%.”

It’s one of running’s most repeated rules, but the evidence doesn't support using 10% as a simple weekly-volume ceiling. A randomized trial found no reduction in injuries from a gradual program based on the 10% rule, and newer research following more than 5,000 runners found no relationship between week-to-week percentage changes and injury rates.

Cliff Pittman breaks down where the 10% number does show up in the research, why different systems in the body adapt on different timelines, and why progressing while healthy is fundamentally different from rebuilding after an injury.

HOST

Cliff Pittman is the Coaching Development Director at CTS, leading the Ultrarunning and Cycling Coaching staff with a specialty in guiding athletes from first-time ultrarunners to elite competitors at races like Western States 100, Leadville 100, and the Triple Crown of 200s. A competitive trail and ultra athlete himself, Cliff brings firsthand experience and a rare ability to turn complex training science into simple, actionable coaching.

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Resources:

• https://pmc.ncbi.nlm.nih.gov/articles/PMC12421110/
• https://journals.sagepub.com/doi/10.1177/0363546507307505