Research shows that weight training is an excellent method of improving performance for endurance athletes. A recent study of elite Danish National team cyclists showed that doing a concurrent strength training program significantly improved time trial performance, and induced a loss of body fat with no significant muscle hypertrophy.
The study used a control group that only did regular cycling training and a concurrent group that did regular cycling training and weight training using a periodized program with loads ranging from 70 to 88 percent of the 1RM.
Results showed that the concurrent training group lost 2 percent body fat, increased quadriceps strength by 12 percent, and improved 45-minute time trial performance by 8 percent. Performance improved because the cyclists increased peak power and were able to work at a higher rate for longer. In comparison, the endurance-only group gained no strength and had no change in time-trial performance.
There was no evidence of hypertrophy in the quadriceps in the concurrent training group, however, they did increase lean mass by about 2 kg, indicating hypertrophy in other muscles of the lower body. Still, due to the 2 percent loss of body fat, the concurrent group ended with the same body weight as before the study, which is notable since endurance athletes generally want to avoid gaining weight due to the fear it will make them slower. It’s true that gaining body fat would make them slower, but if the gains come from type II muscle, an athlete can get faster, as seen in this study.
Researchers suggest that when endurance and weight training are done concurrently, the endurance training provides an “atrophy” stimulus that blunts the muscle growth response that is normally produced by heavy weight lifting. The result is an increase in neuromuscular strength and greater motor unit recruitment, but no significant muscle gains.
The bottom line is that endurance athletes will benefit from a commitment to strength training: You can improve speed and work rate, while shedding body fat.