The question: Should I start my workout with strength or cardio?
The expert: Exercise physiologist Marta Montenegro, CSCS, SFN, NSCA-CPT
The answer: Where to begin? For most women, the right answer is at the weight racks.
See, when it comes to slimming down and shaping up, strength training and cardio work best in that order. Here's why: When you start your workout with weights, by the time you get to the treadmill or bike your anaerobic energy systems will already be tapped out, meaning your body will have to resort to burning fat to keep your aerobic system going strong, Montenegro says. That means more calories burned, not just in the gym, but after your cool-down, too.
Also (and this should be common sense), but if you log your miles and then try to do squats, those squats are likely to be weak and sloppy, she says, neither of which makes for eye-popping results.
Still, there are reasons to make a beeline toward your fave cardio machine as soon as you set foot in the gym—like if you're training for a half-marathon. In general, it's best to prioritize whatever's your goal, be it endurance, strength, or even toning a certain muscle group. In fact, one study in the Journal of Strength and Conditioning Research found that whichever muscle you train first reaps the biggest benefits.