The 10% Rule Reframed

“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 s...