Riding a stationary bike at high intensity for 6 seconds, resting a minute and repeating the cycle 10 times led to a 10% improvement in fitness among people who performed the workout for two weeks, according to a study from Abertay University in Scotland. Researchers said the results may be linked to lactate, a substance that appears in the bloodstream during exercise as a fuel to help people perform at higher levels. BBC (9/17)