Q: What is more effective for an hour of exercise — 30 minutes of cardio and 30 minutes of weight lifting? Or vice versa ? Is there a science on which should be done first?
Many dedicated gym-goers have heard that aerobic and resistance-style exercise should not be combined in a single workout; or if they are, that one or the other must come first. The theory behind these claims is that each form of exercise interferes, physiologically, with the other, potentially blunting the desired training effects.
But the best available science disagrees. In an interesting study published in March in the Journal of Applied Physiology, healthy young volunteers vigorously rode a stationary bicycle using one leg and then completed resistance exercises with both legs, meaning that one limb did both types of exercise; the other only weights. After five weeks, both legs had grown equally large and strong. Cycling first had not reduced the impacts of weight training.
Similarly, a 2012 study of sedentary, middle-age men found that they developed specific molecular changes in their leg muscles after riding a stationary bicycle that were distinct from those occurring on a separate day after lower-body weight training. But when the men performed both forms of exercise one after the other doing half as much of each, they robustly developed both types of molecular responses.“
We saw no indications of interference,” said Stuart Phillips, a professor of kinesiology at McMaster University in Hamilton, Ontario, who oversaw the study.
Perhaps most telling, the order of the exercises in these studies was immaterial. In the 2014 study, the men rode and then lifted; in Dr. Phillips’s study, they lifted and then rode. Muscles, it seems, “can’t tell the difference,” Dr. Phillips said.So don’t worry overmuch about which exercise comes when. “Just set up a workout regimen that happens to be convenient for you,” Dr. Phillips said.