Brian MacKenzie’s Controversial New Approach to Marathon Training

The results were stunning. By several key measures of exercise performance—number of mitochondria (an indicator of how efficiently a muscle is using oxygen), buffering capacity against lactic-acid buildup, and the presence of glycogen (sugar) for fuel—the groups “showed remarkably similar improvements in exercise performance.” The difference: one group exercised for more than 10 hours, the other for only 15 minutes. In another study, just two weeks of sprints nearly doubled cyclists’ endurance when they pedaled at a fairly vigorous pace, from 25 to 50 minutes.

By Christopher Solomon

Read More: OutsideOnline