Cardio is incredibly important for all of us. It’s the bedrock of the physical activity guidelines for health, and if you already strength train, adding in cardio will make you healthier in general and better at the stuff in the gym that you care about. (And no, it won’t kill your gains.)
So where should you begin if you’re starting (or re-starting) a cardio habit? The simple answer is that you can do anything that you enjoy, so if your favorite exercise isn’t on my list below, but it meets the definition of cardio, you don’t need my approval—just go do it. But if you want some more information about your best options, read on.
What counts as cardio?
Cardio exercise is generally understood to be exercise that:
Uses most of your body, or at least several large muscle groups (cycling “only” uses your legs, but it absolutely counts).
Is rhythmic and repetitive—think of the footsteps in jogging, or the arm strokes in swimming.
Can last for 10 minutes or more. It’s fine to do cardio in shorter bursts, but we want to draw a distinction between things like jogging (which people often do for 30 minutes or more) and strength exercises like squats (which might be done for a set of 8 or 12 reps, and then you need to rest before you do more).
Is intense enough you feel like you’re working. A leisurely stroll isn’t cardio, but a brisk walk could be.
Cardio machines you might see in a typical gym include the treadmill, elliptical, exercise bike (all kinds), rower, and stair climber. Those all count as cardio. Strength training work doesn't count--it's still good for you, but it's a separate thing.
How much cardio should I do?
The American Heart Association, the World Health Organization, the CDC, and many other organizations have settled on a guideline that says your baseline should be 150 minutes or more of moderate cardio per week. (They often say “exercise” but if you read the fine print, they are referring specifically to cardio. Strength training is separate.) Specifically, they say you should do:
150 minutes of moderate cardio per week, or
75 minutes of vigorous cardio per week, or
Any combination of the above (adding up to 150, with each minute of vigorous cardio counting double), or
If you’re already meeting that baseline easily, you should aim for 300 minutes of moderate/150 minutes vigorous.
What does 150 minutes per week look like? Here are some examples:
A 30-minute jog every weekday at lunch, or
A 50-minute session on a spin bike three times a week, or
22 minutes of brisk walking every morning (even weekends)
How hard should a cardio workout feel?
If you’re out of breath, feel like you’re dying, and can’t wait until it’s time to stop, you’re going harder than you need to. Moderate cardio is basically the same as “zone 2” cardio. It should feel like work, but not torture. You’ll be breathing a little heavier than at rest, but you could still easily speak in full sentences. These workouts are easy to recover from (you don’t need rest days in between them) and you’ll generally feel better at the end than you did at the beginning.
Vigorous cardio includes everything harder than that, from sprints that have you pooped in five seconds, all the way down to tempo runs where you’re pushing the pace but you’re able to keep going for the length of a whole workout. You may feel exhausted at the end. You may not be able to do this kind of workout every day. Vigorous cardio is good for you, but it’s often best in small doses. Endurance athletes (like runners) often aim to keep this stuff to 20% or less of their weekly workouts.
While heart rate tracking is popular, I don’t recommend using heart rate to tell the difference between your moderate and vigorous workouts. The heart rate zones that are built into your watch are inconsistent from device to device and they use a formula that is often wrong. Judge the difference from your breathing and your perceived effort. Moderate cardio is about a 3, maybe 4 on a scale of 1 to 10.
Does it matter what kind of cardio I do?
Honestly: not that much. Sometimes people seek out cardio that uses their full body, or that targets specific body parts, but that’s not actually very important when it comes to the health and fitness benefits. A rowing machine uses your arms more than a spin bike, but both can provide a great cardio workout. If you want to build muscle in your arms, you’re better off doing some strength exercises for your arms rather than worrying about whether your cardio workouts include your arms.
The best cardio workout is whatever you’ll do, so the most important factors are how available the workout is to you (is there a rower at your gym?) and preference (do you like rowing?).
With that huge caveat out of the way, I’ll give you guys my favorite cardio workouts, and some tips for working each into your routine.
The cheapest cardio workout: running (or run/walk)
Let’s start with what is, for many, the most accessible cardio workout of them all: stepping out of your front door and putting one foot in front of the other. (Nothing is perfect for everybody, of course, so if outdoor workouts don’t fit your life, skip to the next section.)
You’ll need a pair of shoes that feel reasonably comfortable when you run (they do not have to be expensive running shoes) and many of us will need a sports bra. Then, just add some athletic clothes, and you have the essentials. You’ll need the same basic gear for most other exercise, anyway.
You do not need a running watch or a heart rate monitor. You don’t need to track your mileage or pace at all, although you may find it useful to be vaguely aware of how long your workouts are taking and to track how often you do them. That can be a note in your phone (“30 minutes jog Monday”) rather than buying into an app or device ecosystem.
Here’s a sample workout, if you don’t know where to get started:
Walk for the first 5 minutes, as a warmup. Start slow, and by the end, try to be at a brisk pace.
Speed up a bit; try a jog or a fast walk.
If you start to feel tired, slow down just a little bit. Don’t return to a slow walk unless you truly have to.
Speed up again when you feel ready, and repeat.
Over time, work toward keeping up a steady pace. A slow, steady jog is better (for most of your training) than sprint-and-walk intervals. That said, interval training is a fun thing to sprinkle in. If you’re worried that running is boring, try these tips to keep it fun.
Easiest on your body: indoor cycling
If I had to crown a best all-around cardio workout, it would probably be spinning. There’s a smoother transition between speeds, rather than the distinct categories of “walking” and “running,” so it’s easier to find the right intensity for a given workout. There’s not much bouncing or impact, so you may not need a sports bra and you may find it easier on your knees and shins at the start. And you can do it with a water bottle and a fan within reach, which makes logistics a bit easier—no need to carry everything with you.
(Outdoor cycling is great, by the way. But that requires a helmet, a bit of mechanical know-how, and street smarts to safely mesh with, or avoid, traffic. I’m sticking with indoor cycling for my recommendation here, but if you love taking your bike to the streets, by all means enjoy!)
There are also tons of options for indoor cycling workouts. You can aim for a straight steady-state workout, perhaps watching a favorite show while you do it on the gym’s TV or even your phone. Or you can follow along with a video or audio workout that guides you through intervals while distracting you with music and chatter. Use an app like Peloton or Aaptiv, or find videos on YouTube. Here’s one to start you off:
Best for no equipment at home: put on some music and dance
I really debated this one. There’s a lot to be said for jumping rope (even though technically that is “equipment”) but the pros and cons are similar to jogging. There’s a lot of bouncing and impact, and it can be pretty exhausting at first, until you learn how to pace yourself.
Then we have the staples of bodyweight “HIIT” videos, like air squats and jumping jacks. These are fine! But they lend themselves better to intervals, and when we’re doing cardio it’s good to have options that let us move continuously. That said, I’m going to put in a quick plug for the most underrated no-equipment cardio move out there: the old school four-count burpee. (I describe it in more detail here.) No jump and no pushup. You’re welcome.
But ultimately, if you want to get a good cardio workout in your home without having to buy equipment or clear a big space, just put on some music and dance. And don’t tell me you “can’t dance,” because you don’t need to impress an audience here. Put on something that makes you happy, and shift your weight from one foot to the other. Swing your arms a little. Look! You’re dancing! It may not look stylish, but you’re getting a workout and you’re probably enjoying it a lot more than burpees or squat jumps.
Obviously, there are so many directions you can go from here. You can simply bop along to whatever is on the radio or shuffle your Spotify. You can work on building your skill as a dancer, learning new moves and stringing them together—don’t these goofballs look like they’re having fun dancing the Charleston? You can look up dance cardio videos where an instructor leads you through a workout. Or you can just pick any style you like and have fun with it.