The advice from James Cook University sports scientists comes after the team carried out a study looking at concurrent training, which features both resistance (e.g., weights) and endurance training (e.g., running) on the same or separate days. In their research, the team found studies showing that athletes, including runners and cyclists, had a reduction in performance even several days after a single resistance training session. Previous research, too, indicated that short breaks between workout sessions can boost muscle growth.
“The consensus is that concurrent training is beneficial for endurance development. But we found that if appropriate recovery is not accounted for between each training mode, then it may impair endurance development,” explained JCU’s Dr Kenji Doma.
Doma added that a typical resistance training session which lasts between 40 to 60 minutes causes a physiological stress that can continue for several days post-exercise, and a 24 hours rest period may not be enough. Although Dr Doma added that the team do not suggest stopping concurrent training, as “There are great benefits to it,” he added that “There can be some hidden dangers too. What we want to see is fatigue from resistance sessions minimised so there can be even more benefits gained.”
Although the team pointed out that they do not know how long rest periods should be in order to minimise this fatigue (as that depends on the individual and where they are in their training schedule), they concluded that increasing awareness of fatigue may encourage coaches to look at modifying their methods. It could include the order of training, length of recovery period and training intensity to limit the effects of fatigue from resistance training on endurance training sessions. The findings can be found published online in the journal Sports Medicine.