Cardio and weights are both key components of any fitness program, whether you’re trying to stay healthy, lose weight, or excel in athletic competition. But how do you combine the two? That’s the question we’re tackling today—and I’m sorry to say that the answer is “it depends.” 

Is it OK to train strength and cardio together? 

For most people, it doesn’t really matter whether you train strength and cardio in the same session, in different sessions on the same day, or on different days throughout the week. If you have a routine that fits your life, you’re better off than somebody who keeps trying and failing to do the “optimal” thing. As I’ve written before, optimal is optional. 

But to give you some general tips: 

If you’re trying to be really good at one type of fitness, your most important workouts should get their own dedicated time. 

Strength and cardio can interfere slightly with each other if you do them in the same session. If you have the time budget for two-a-days, you might want to do one workout in the morning and the other in the evening, rather than trying to do both at the same time. 

If you’re trying to be good at a type of fitness that combines strength and cardio (like Crossfit, or many team sports), it’s okay to combine them most of the time. You may still want to do some focused weights-only or cardio-only sessions. 

If you’re just trying to stay healthy or lose weight, go ahead and do your workouts whenever you can. If you don’t end up gaining quite as much strength as an elite powerlifter, I’m guessing you’ll be fine with that.

Why you might want to do strength training first

You’ll be fresh for your strength work

To get the most out of strength training, you’ll want to show up ready to put in some serious work. For the same reason we rest several minutes between sets, we also don’t want to show up to a strength workout already pooped from a long session on the exercise bike. 

If you’re fatigued at the start of a strength session, you won’t be able to lift as much weight. You also might find yourself more likely to get bored or tired and say “fuck it” and go home. Starting your strength workouts fresh will help you to get the best strength and/or muscle gains for your effort.

Easy cardio doesn’t suffer (much) at the end of a workout

You might think the argument for showing up fresh would apply to all workouts, but that’s not really the case. A lot of your cardio should be fairly low intensity stuff (that “zone 2” you keep hearing about) and it’s not a big deal to do zone 2 work when you’re already fatigued. 

Let’s say you aren’t up for a strong running performance after you’ve finished five sets of heavy squats. So what? You can do an easy jog, or even a brisk walk, and still get in a perfectly good zone 2 cardio workout. 

If you’re a strength athlete, you’ll want to get right to the point

I hate a lengthy warmup, and maybe you do, too. If you’re more of a strength training person, it may feel better to treat your cardio as an afterthought, something that gets done after your real work for the day. Instead of hopping on the bike and wondering how much cardio might affect your day’s workout, you can sit on the bike after you’ve done your squats for the day, and pedal away mindlessly without worrying about performance. 

Why you might want to do cardio first

You have a hard workout you want to be fresh for

While your easy cardio sessions can kind of go anywhere, most cardio-focused athletes will have key workouts that deserve their full attention and effort. If you train with weights on the same day as track intervals or a long run, you’ll definitely want the weights to come last. 

You’re getting used to a new cardio routine

Beginner runners know that running can be hard at first; the same might be true of any other form of cardio you just started doing. Showing up fatigued is not going to make these workouts any more fun. Better to get your easy run in, then follow it up with a quick strength workout, than do it the other way around and find yourself discouraged because you need to take more walk breaks than usual.

Strength work is truly an afterthought for you

If you love running (or cycling, etc) and don’t care much for lifting, your post-cardio time might be your best option for getting a lifting session in. You’ve got a bit of a mood boost going from that great run you just had, you’re nicely warmed up, and—let’s be honest—you probably won’t head to the gym just for a strength workout. 

This doesn’t describe everybody, but be honest with yourself if this sounds familiar. The risk in leaving strength work for last is that you might end up skipping it entirely. But if you need to budget the time somewhere, ask yourself if you can commit to a post-cardio strength routine twice a week or so.

How to choose whether cardio first or lifting first makes sense for you

The easiest way to choose is to do the most important workout first. Runners should usually run first, powerlifters should usually lift first, and so on. 

If you aren’t able to pick a side, another good rule of thumb is to do the hardest workout first. Deadlift day followed by an easy 20 minutes on the bike, for example; or an evening of 400 meter repeats on the track followed by a few sets of lunges and pushups. 

If you truly cannot decide, and you want me to flip a coin for you: most people should do weights first. It’s hard to get the benefits of strength training without putting effort into it, and it’s hard to put effort in when you’re fatigued. 

Is it bad to do cardio to warm up before lifting? 

A warmup of 10 minutes or so is a great way to get ready to lift, especially if it’s mostly low intensity work (in other words, it feels like a warmup) and it’s relatively short. I wouldn’t count that as a full cardio “workout,” but I would count it toward my total minutes or miles of cardio for the week. 

What if I’m super tired after my first workout? 

You should only stack workouts if you’re able to put in a good-enough effort for the second one. If your first workout leaves you exhausted, that might not be a good day to tack on a whole second workout. Consider doing that other workout on a different day, or even later the same day.

That said, try having a snack between the first and second workouts—even a sports drink or candy bar will help. Carbs (including sugar) make for an excellent energy boost during long workouts. If the first workout is long (60-90 minutes or more), carbs are likely to help. If the first workout is short but really intense (like 20 minutes), you may just need to sit around a rest a little bit before diving into the next chapter. Carbs won’t hurt in this case, though.

Should I always do my workouts in the same order? 

No, you don’t have to! It’s totally fine to swap the order as needed. For example, a weightlifter might tack on cardio after lifting most days, but then have a day that’s dedicated to cardio where they might do a few lifting accessories afterward. 

And if you have a set routine, but something disrupts it—you have to finish early to take your kid to an event, or whatever—feel free to move things around as needed so you get in as much of the important work as you can.

How much time should I wait between my workouts?

You can jump straight off the leg press machine and head to the elliptical, so there’s no minimum time. But if you find yourself scheduling separate workouts, the rule of thumb is that 6 hours gives you a decent amount of recovery time. Eat a good meal with plenty of carbs after the first workout if you can—that replenishes glycogen stores so that you’ll have more energy going into the second workout.