Training With Reduced Carbohydrate Availability Enhances Fitness
Interval training— repeated bouts of high-intensity exercise interrupted by short rest periods— increases fitness rapidly. Researchers from McMaster University in Canada found that subjects practicing interval training two times per day for two weeks gained fitness faster when they consumed only small amounts of carbohydrates between sessions. Interval training consisted of five sets of four-minute cycling at 60 percent of maximum effort followed by two minutes of recovery, practiced twice a day. Subjects consumed either 195 or 17 grams of carbohydrate between exercise sessions. Gains in peak power output were approximately 50 percent greater in test subjects consuming low amounts of carbohydrates between training sessions. These subjects were active but not well trained, so it is not known if these effects would apply to serious athletes or extend longer than two weeks. (International Journal Sports Nutrition Exercise Metabolism, published online March 26, 2015)