If you’ve ever taken a Barry’s class, you’ve probably agonized over a key decision: Do you start with cardio or weights first? (Or maybe you’re not an overthinker and you just pick one, in which case, congratulations.)

Even if you’re not familiar with Barry’s, which involves alternating between treadmill intervals and strength training, odds are you’ve done workouts that involve both strength and cardio, whether that looked like lifting weights at the gym before hopping on the stationary bike, following up your run with some body weight exercises at home, or taking a class that got both your heart rate up and muscles burning.

But is it worth puzzling over which part of your workout should come first? As it turns out, it does make a difference whether you choose to do cardio before or after weights. Here’s what you should know when your workout calls for both.

Should you do cardio and weights on the same day?

Sure, you could have a perfectly balanced fitness routine that doesn’t involve doing cardio and strength training on the same day. But if you’ve been wondering, “Should I do cardio or weights first?” there are benefits to doing them together, says Cathlin Fitzgerald, PT, DPT, CSCS, a physical therapist, running coach, and certified strength and conditioning specialist at NYC Custom Performance.

For one, it’s often convenient, a key factor considering how challenging it can be to find time in the day (or the week) to get a workout in. But it’s also about what Fitzgerald calls “keeping the hard days hard and the easy days easy.”

“The idea is that you’re going to give yourself more opportunity to recover on your easy day or your rest day, as opposed to stretching the work out across six or seven days a week,” she says. In other words, if you can pack more into one day, you’ll give your body more of that much-needed recovery before it’s time for your next workout.

The case for doing cardio first

Whether you kick things off with cardio or strength largely depends on your goals, says Ash Wilking, CPT, a NASM-certified personal trainer and Tonal coach. Whatever you’re looking to prioritize should come first.

For instance, if you’re training for a race, trying to get faster (whether on your feet, on a bike, on a rower, or in the pool), or generally hoping to improve your aerobic endurance or cardiovascular health, cardio is probably going to be your priority and therefore you’ll want to tackle it first.

“The best way to think about it is: Where do you want the majority of your energy to live?” Wilking says.

That calculation could change depending on the day. For instance, if you’re training for a marathon and have a speed workout on deck, you’ll want to tackle that before your lift session. (Keep your hard days hard, remember?) But if your training plan calls for an easy run and you’re hoping to sneak in some reps, you could get a solid strength workout in and still have enough in the tank for a few chill miles afterwards.

Another perk of doing your cardio first? It’ll get you nice and warm for your strength session, Fitzgerald says. Just be sure to also get in some dynamic stretches before you start lifting anything, she says.

The drawbacks of doing cardio first

Whatever you choose to do second is going to suffer at least slightly from the fact that you’re already tired from what you did first, Fitzgerald says. “That run will be affecting how much you can lift, and then your running performance will be affected if you’re lifting first,” she says.

But there is an extra downside to starting with cardio: Cardio has a larger negative impact on strength training than vice versa, Fitzgerald says. (So, if you don’t have any specific goals, it’s generally recommended to do strength first.) “You won’t be getting the same muscular gain if you do the running first,” she says.

Just how much your cardio is going to impact your strength workout depends on how intense and long it was, and how long you wait to tackle those weights. Waiting at least six hours will set you up for the most success, Fitzgerald says, but if you’re doing them back-to-back, just be mindful of not overworking the same muscle groups (so if you started your workout with sprints on the track, maybe *don’t* focus on your hamstrings during your strength block).

Also keep in mind that if your body is already tired from doing cardio, “there could be a breakdown in movement patterns,” Wilking says. “You have to be very cognizant of the fact that when you go to deadlift or squat, you’re more fatigued. That’s not a bad thing—working in a fatigued state is really good for our muscular development, it’s just being aware.”

“At the end of the day, it comes down to being consistent and building on that consistency.” Cathlin Fitzgerald, PT, DPT, CSCS

The case for doing strength first

If you want to be on the top of your game during your strength workout, do it first, Wilking says. Maybe you have a specific strength related goal—to be able to do a pull-up, to increase your one-rep max (the most weight you can lift for a single repetition), or to build more muscle mass—or maybe you’re just in a season of fitness where strength’s your priority.

“That way, you’ll get the most benefit when it comes to both strength and hypertrophy,” Wilking says. “You’ll still be able to do cardio—it’ll be secondary but you’ll still get the benefits of cardiovascular work.”

The drawbacks of doing strength first

“The more tired we get, the less likely we are able to work at our best performance,” Wilking says. So depending on how hard you went in your strength session, your cardio session could feel quite challenging. (Think: legs that feel heavier than usual or paces that are slower than you’d typically go.)

And just like lifting while tired from cardio can lead to your form getting sloppy, the same is true in the reverse—so if you’re running, swimming or biking post-strength sesh, pay special attention that you aren’t accommodating already tired or sore muscles by slacking on your form.

How to combine cardio and strength training into one workout

Want to make your workout a double-header? There are lots of ways to combine cardio and strength—here are a few suggestions from Fitzgerald and Wilking.

If you want to prioritize strength:

• Start with three sets of 10 reps each of the following: Weighted squat into overhead press, bent-over row, deadlift, and farmer’s walk.
• Then, either ditch the weights for a cardio finisher, doing three sets of the following for 30 seconds each: squat jumps, push-ups, and bicycle crunches; or finish with 30 to 40 minutes of low-intensity cardio.

If you want to prioritize cardio:

• Start with an interval workout (whether that’s on the track, the bike, or the rower) or a threshold workout (meaning 20 to 30 minutes of sustained moderate-to-high intensity cardio work, plus a warm-up.)
• Then, do a 30-minute strength session, focused on either your entire body, your core, or your upper body, with light-to-medium weights.

How to build a cardio and strength routine

If you’re new to fitness or building out your routine for the first time, Fitzgerald suggests keeping your strength and cardio sessions separate. “Maybe that’s getting into the gym twice a week to lift, and then doing cardio three times a week at an easy conversational effort,” she says. “Use that lower intensity to build the habit before you start doing the harder stuff.”

Already have a fitness foundation? There are countless ways to program both cardio and strength into your routine, whether together or separate. “The first thing is always going to be what fits into your schedule,” Wilking says. “The second is mapping out your recovery within those workouts.”

Whatever you do, be consistent and have a plan. “It’s okay to do random workouts and jump into things that we like, but we just have to be very aware that our results will be based on what we’re doing, so if we choose a bunch of random things, we might not see the results that we want,” Wilking says.

And don’t forget: Cardio and strength are not always two distinct categories, and some strength workouts can have cardio benefits. Want to get your heart rate up during your strength session? Use lighter weights, increase the speed, and work for longer before taking a rest, Wilking suggests.

The bottom line

As long as you’re balancing strength training, cardio, and recovery in your routine, you probably don’t need to stress too much about the order of operations. “At the end of the day, it comes down to being consistent and building on that consistency,” Fitzgerald says.