If you’re a regular gym goer you likely already do split routines, working different muscles on different days. “That’s fine when you can control your own schedule every day of the week. But over the holidays, when obligations pile up, so do the missed workouts.

That’s why it makes sense to switch to total-body workouts, hitting all your muscles each time you lift,” says  Lou Schuler, author of Strong: Nine Workout Programs for Women to Burn Fat, Boost Metabolism, and Build Strength For Life.

You’ll get more from each workout and probably gain some muscle and increase strength, according to a surprising recent study in the Journal of Strength and Conditioning Research. “The lifters assigned to do total-body workouts gained more strength and size than the ones doing body-part splits, most of whom had previously used split routines,” adds Schuler.