Yet *Another* Study Finds That Regular Resistance Training Builds Muscle Strength

Researchers out of Japan and Australia recruited 36 healthy young adults for this study. They were curious to see how doing the same workout—an arm resistance exercise lowering a heavy dumbbell in a bicep curl—at different intensities and frequencies affected fitness results. One group did a set of six contractions one day a week (low intensity, low frequency), another did a set of 30 contractions one day a week (high intensity, low frequency), and the last did a set of six contractions five days a week (low intensity, high frequency).

Everyone kept up with this routine for four weeks before getting their muscle strength and muscle thickness measured. After the month was up, those in the group who did a set of six contractions five times a week were the only ones who saw significant gains in both muscle strength and thickness. The group who did 30 contractions in one day saw an increase in thickness but not strength, while the group who did six contractions in one day did not increase muscle size or strength.

Consider this yet another reason to opt for frequent repetitions of Zone 2 exercise (the level of exercise where you can still hold a conversation) over the occasional all-out workout.

"People think they have to do a lengthy session of resistance training in the gym, but that's not the case. Just lowering a heavy dumbbell slowly once or six times a day is enough," study author Ken Nosaka, Ph.D., says in a statement. "We only used the bicep curl exercise in this study, but we believe this would be the case for other muscles also, at least to some extent." (In mindbodygreen's mbg moves library, there is a treasure trove of lower-impact routines tailored to each muscle group.)