Similar to many others, Bob Hickson opted to study exercise physiology because of his avid hobby of powerlifting. He wanted to learn the science behind what causes muscle growth, and possibly develop new and more effective ways to build muscle and strength. Luckily, Bob was a good student and managed to get accepted into an elite academic post-doctoral fellowship at the Washington University Medical School in St.Louis. There, he studied under professor John Holloszy, considered the "Father of endurance exercise research." Dr.Holloszy was a man who literally practiced what he preached, as he engaged in daily jogs around the college campus and a local park each day after his teaching duties ended. Since Bob Hickson wanted to make a good impression on his new mentor, he decided to join Holloszy on his daily jog. Bob continued his heavy powerlifting training at the same time, but he soon began to notice that he was losing muscular size and strength. At first, this proved a mystery. He hadn't made any drastic changes in his weight workout, wasn't overtraining, and was consuming plenty of protein. So what could be causing the rapidly declining muscle/strength effect? The only thing he had changed was adding the jogging routine. When he suggested to Dr.Holloszy that perhaps adding jogging to his weight workout was causing a loss of muscle mass and strength, Holloszy told him, "That should be the first study you do when you have your own lab."
And so it was. When Dr.Robert Hickson established an exercise science laboratory at the University of Illinois in Chicago, his initial study was the first study ever published about the effects of concurrent training. This study, published in 1980, featured three groups: 1) Strength training alone;2) Endurance training alone; 3) Strength and endurance (concurrent) training. Those in the strength-only group trained 5 times a week for 10 weeks, using an exercise routine designed to increase leg strength and mass. The subjects lifted as much weight as they could during the course of the study. Those in the endurance group also trained for 10 weeks, using a 6-day-a-week routine that involved 3 days of cycling, and 3 days of running. The cycling portion of the program involved six, 5-minute intervals at maximum oxygen intake (VO2MAX). When running, the workout involved running as fast as possible for 30 minutes a day the first week; 35 minutes, the second week; and 40 minutes a day for the remainder of the study. Those in the concurrent group took between 15 minutes and 2 hours rest between weight and endurance workouts.
At the end of the 10-week study, the subjects tested for any improvements in maximum oxygen intake through testing on both an exercise bike and a treadmill. The strength alone group showed a 4% improvement in VO2MAX on the bike, but not . . .