Podcast: Is ‘Cozy Cardio’ as Effective as High-Intensity Workouts?

[Dr. Hennessey]

Cardiovascular exercise in that moderate range is the sweet spot. That’s where you’re training your heart and your lungs to use oxygen more efficiently, and what then comes from that is increases in your metabolism, so your muscles are now pulling that oxygen in. That’s using more energy. That’s taking, then, glucose out of your blood to build up your muscles more.

[Courtney]

Welcome to Health Matters, your biweekly dose of the latest in health and wellness from NewYork-Presbyterian. I’m Courtney Allison. 

This season on Health Matters, we’re covering your health from A to Z, asking our experts to break down the health topics and wellness trends we’re all curious about. For letter C, we’re learning about cozy cardio. 

We all know that exercise is good for our heart, but is low-impact exercise just as effective as high-intensity workouts? 

To find out, we talked to Dr. Jessica Hennessey, a cardiologist at NewYork-Presbyterian in Columbia, who explains how to get the most out of cozy cardio workouts and how to make an exercise routine sustainable. 

[Courtney]

Dr. Hennessey, welcome to Health Matters. Thank you so much for joining us today. 

[Dr. Hennessey]

Thanks so much for having me. I’m happy to be here. 

[Courtney]

So, we’re here today to talk about exercise and the heart, and I’d love to ask you about the trend, “cozy cardio.” Is this something you’ve heard about, and what’s your interpretation of cozy cardio? 

[Dr. Hennessey]

I’ve certainly heard about it. I think where cozy cardio comes in is any movement is good movement.

[Courtney]

Mm. 

[Dr. Hennessey]

You’re stuck working from home; cozy cardio is a great way to use your lunch break. You get on your walking pad. Why do you have to get all dressed up and go to a gym? I think the cozy part is really twofold. One, convenience. It’s here. It’s home. And secondly, it’s comfortable, right? We’re all not always comfortable being at a gym, doing things in public, so you sort of get the best of both worlds out of this cozy cardio trend. 

[Courtney]

Yeah, ’cause sometimes it’s hard to get out the door. There’s just, like, a barrier to getting out of the house and going to the gym, so I love the idea of just staying home, finding something that works for you. Could you give a few more examples of what might be considered cozy cardio? 

[Dr. Hennessey]

Another way I personally use it is for my rest days and stretching. So sometimes, especially now in the wintertime up here in New York, sit by the fire, and I’ll sit and stretch in- 

[Courtney]

Mm. 

[Dr. Hennessey]

… the warmth of the fire. And it’s a really nice way to just get your body moving in a more comfortable and convenient way. Other ways are actually having real exercise equipment in your house, and that may be a treadmill, a bike, some weights, whatever it might be. 

[Courtney]

And so why focus on moderate, sustainable forms of cardio rather than just high intensity? 

[Dr. Hennessey]

Moderate exercise is sustainable, and that’s really where you start having slow and steady improvements in lots of things: your cardiovascular exercise tolerance in general, your VO2 max, that number that we use to say how well our heart and our lungs are working together, as well as your metabolism ultimately. You’re training your body in a sort of slow and steady process to say you’re getting stronger. You’re gonna be more efficient with your movements. You’re gonna be more efficient with your use of your energy, and that’s where that moderate-intensity exercise really hits all of those different points. 

[Courtney]

Mm-hmm. 

[Dr. Hennessey]

The beauty of moderate exercise is that it does provide all of those at a slow and steady manner. 

[Courtney]

You know, as you’re talking, there’s, um, a barre studio I started going to near my apartment, and what you’re just saying about sustainable… And I actually think of it as cozy ’cause it’s only two blocks away, so I kind of roll out of bed, go there with my coffee, and it’s just been wonderful. So, I think when something is accessible, it’s just so much easier to stick to as well. 

[Dr. Hennessey]

Totally, and barre is a really great example of moderate ’cause it sort of encompasses some strength, right? 

[Courtney]

Mm-hmm. 

[Dr. Hennessey]

You have weights. You’re moving at more of a clip, so there’s more cardiovascular movement to that, and so I, I love that. And it’s low impact, right? 

[Courtney]

Yes. 

[Dr. Hennessey]

That’s, I think, the other big thing for those trying to get back into exercise.

[Courtney]

Well, yeah, so, I mean, does cozy have to mean easy or just accessible? 

[Dr. Hennessey]

I think accessible is the word that you’re totally right. I think convenient, accessible, and comfortable, I think that’s really the difference. My definition of comfortable is different than yours, is different than anybody’s. 

[Courtney]

Mm-hmm. 

[Dr. Hennessey]

So, I think it’s being comfortable in what you’re doing is the key to cozy cardio. 

[Courtney]

So how might we incorporate cozy cardio into our lives? Does it take the place of more intense workouts, or maybe there’s a place for both kinds of exercise in our lives? 

[Dr. Hennessey]

Yeah, so if you kind of go with the AHA recommendations, they will say at least 150 minutes of moderate-intensity exercise per week or greater than or equal to 75 minutes of high-intensity exercise per week or some combination of those. And so, it’s unlikely you’re gonna be doing high-intensity exercise when we’re calling something cozy cardio, so we’ll take that off the equation. But are you gonna walk vigorously? That would be an example of moderate exercise for 30 minutes in your house while you’re watching your show- 

[Courtney]

Mm. 

[Dr. Hennessey]

… or while your kids are running around, and you can’t really escape out to the gym. 

[Courtney]

So, I’m wondering, when it comes to walking versus running, what is the better one for lasting health? Can I get a good workout in with a brisk walk? 

[Dr. Hennessey]

You can if you get your heart rate up appropriately. 

[Courtney]

Okay. 

[Dr. Hennessey]

And if you don’t have a heart rate monitor, you can use, “How easily can I have a conversation while I’m doing this?” So, if you’re moderately exercising, you can talk, but you can’t sing, would be the rule. Whereas, say, you get up to jogging or running, you can maybe get through one sentence. And so as long as you get yourself up to that moderate level, then yes is the answer to that. 

[Courtney]

Could we break down what are the benefits of walking for your heart, for your body? What are the benefits of running? 

[Dr. Hennessey]

Running is gonna have a bigger impact in a shorter period of time. Your heart rate is then going to be up. You’re in that vigorous exercise category now, so the heart rate’s gonna go a little bit higher, and you’re gonna have a little bit more stress on your joints, and you’re gonna be training your muscles more quickly.

[Courtney]

The CDC helps define how fast walking versus jogging versus running is, which we thought was interesting. Moderate-intensity walking is a rate of 2.5 to four miles per hour. 

[Dr. Hennessey]

Okay. 

[Courtney]

And where you fall within that range depends on your fitness level. If you exercise regularly and are in good shape, moderate intensity might mean four miles per hour or a 15-minute mile. I know that 15-minute mile well. If you’re less fit, moderate intensity is closer to the lower end of that range. And we saw one study where a walking pace of about 100 steps per minute, which translates to about 2.7 miles per hour, qualifies as brisk walking for most adults. 

[Dr. Hennessey]

Okay. 

[Courtney]

And to reach vigorous intensity activity, you need to take at least 130 steps per minute, which at just f- over four miles per hour qualifies as jogging. Running is often defined as six miles per hour or faster. Does that all track for you? 

[Dr. Hennessey]

Yeah, absolutely, and I think you made the point of understanding where you live in that realm is also really important, right? 

[Courtney]

Right. 

[Dr. Hennessey]

But yes, I agree. I would say over six miles an hour, which is a 10-minute mile, is start- at the beginning of running, and I agree about four to six is probably the average for jogging. 

[Courtney]

Can we talk more about how does our heart rate serve as a guide for the kind of exercise we’re getting? 

[Dr. Hennessey]

Yeah, so we’ll start in the middle. I think that’s the easiest, ’cause moderate exercise is sort of where we want to live. That’s about 80%, 70 to 80% of your maximum predicted heart rate, which is 220 minus your age. So- 

[Courtney]

Okay.

[Dr. Hennessey]

… 220 minus your age equals 100% of your maximum predicted heart rate, and then we’re talking about 80% of that. So, then you can think about going above that or below that to kind of get to the other ends of the types of exercise we talk about, so keeping it around that 80% mark. That’s where you’re getting your cardiovascular benefit. That’s where you’re training your heart and your lungs to use oxygen more efficiently, and what then comes from that is increases in your metabolism, so your muscles are now pulling that oxygen in. They’re using it more efficiently. That’s using more energy. That’s taking, then, glucose out of your blood, which is great for diabetes- 

[Courtney]

Okay. 

[Dr. Hennessey]

… to build up your muscles more. And so that cardiovascular exercise in that moderate range is the sweet spot. Now, when you get up to high-intensity exercise, that’s when we’re talking about getting above, say, 90, 91% of that maximum predicted heart rate, and that’s when we’re doing that in shorter bursts. That’s where that high-intensity interval training type work comes into play, where you can gain some of those benefits, but typically in a shorter period of time. 

[Courtney]

Can you elaborate more on why it’s so important to give yourself a rest day? 

[Dr. Hennessey]

When we’re getting to the point where we’re in anaerobic, we’re…our muscles create lactic acid, and that’s when you feel sore. That’s from the lactic acid that you feel that your muscle makes, and so rest days are really important for your muscles to repair themselves after you’ve done a harder workout. And so, a lot of times, f- sort of from a schedule perspective, we’ll recommend, okay, you have a real high-intensity day, say, and then after that is your rest day, so you really are giving yourself that time to rest. And rest doesn’t mean zero. Rest can mean some stretching. Rest can mean take a nice walk. 

[Courtney]

Yeah, and it seems like this is where some more of that cozy exercises we’re talking about can come in. 

And I feel like cozy also seems to hint at stress reduction. Can movement help reduce stress, and how does that, in turn, help our heart health?

[Dr. Hennessey]

Totally. There is a lot of data that suggests exercise improves mental health in general, uh, everything from cozy cardio up to high-intensity stuff. Exercise is like stressing your body, in a sense, teaching your heart how to manage stress, right? 

[Courtney]

Right. 

[Dr. Hennessey]

And from down at the physiology level, it’s saying, okay, well, when you are exercising, we release a lot of things, and then we teach our body how to manage those better. Stress is adrenaline and cortisol and all these, buzzwords that you hear—that stuff gets released when you exercise, and that stuff gets released when you’re mentally stressed. And so- 

[Courtney]

Yeah.

[Dr. Hennessey]

… by exercising, you’re still training your body on how to manage those chemicals, those things that are going on in your body. Additionally, sometimes it’s a time to, to veg out, in a sense. So, your brain, you’re, you’re not thinking about the next meeting you have. You’re not thinking about, “Oh, I’m, I’m worried about work or school or whatever it is that’s your stressor. You’re able to zone into your exercise, and by making it cozy, you’re adding that element of, “I’m not just exercising and helping my body, but I’m doing exactly what I want to do.” 

[Courtney]

Yeah. 

[Dr. Hennessey]

“I want to do this,” and then that feels so much better, too. 

[Courtney]

I just feel like you always kind of feel better if you exercise, and that’s how I convince myself to go out, ’cause I’m like, “You’re just gonna feel better.” I don’t always even think about the long-term effects. I just know this is gonna put me in a better mood if I go today. 

[Dr. Hennessey]

Totally. 

[Courtney]

You mentioned high-intensity interval training. I know that’s often shorted to HIIT workouts and that’s another trendy one. Could you say more about HIIT workouts?     

[Dr. Hennessey]

So, number one, I would say HIIT is not one of the things that’s necessarily in any of the AHA guidelines or anything like that as far as exercise, but it is totally a trend, and it’s all about variety in your exercise. We’ve talked about true cardiovascular exercise, we… like walking, brisk walking or running. We’ve talked about the stretching, core, balance movements, and then HIIT is the other end of this spectrum, where these are short bursts of very high-intensity exercises, but then with brief, true recovery, right? So, you’re going from sprinting to you’re walking or, you know, barely walking, walking slowly, basically. The idea behind HIIT is that you can get those cardiovascular gains in a shorter period of time. And, the safety with HIIT is something that’s also important to really make a point of. There’s lots of data for HIIT in cardiac rehab patients, say, in very controlled settings. That’s the important piece of this; is it’s in the controlled setting. And in those cases, those patients have generally lower cardiovascular events. However, I think the biggest thing for HIIT is making sure that you’re safe with it, and that you can do that high-intensity movement without hurting yourself. 

[Courtney]

Yeah, what harms can come from pushing too hard or too often? 

[Dr. Hennessey]

So, anyone with any cardiovascular history, coronary disease, I would say should not do HIIT unless they’ve gone through a rehab program and have doctor permission to do it. Because that stress that you get to is a higher level than you would with moderate exercise at a given point. But otherwise, it’s also your muscles. If you’ve not been sprinting very much lately, adding a sprint workout into your training, you should be careful. 

[Courtney]

And I’d love to spend a little more time on strength training. Could you say more about the importance of strength training for the heart? 

[Dr. Hennessey]

Sure. So, strength training is not one that you’re typically going to get your heart rate up to those levels we were talking about, and that’s okay. Because what you’re actually doing is training your muscles to use oxygen more efficiently and to pull in more glucose. And strength training has the ability to overall help your cardiovascular fitness by getting rid of a lot of those risk factors. You’re gonna increase your metabolism, which means you’re gonna be able to lose weight more easily. You’re gonna lose fat more easily. You’re going to, like I said, pull the glucose out of your blood and give you a lower risk of diabetes. And finally, you’re stronger, and when we’re stronger, especially as we’re getting older, we are less prone to injury. There’s a lower rate of things like osteoporosis in women who do heavier strength training, and it doesn’t have to be crazy heavy. But strength training is another key to improving your body’s overall metabolism.

[Courtney]

That’s amazing, ’cause just as a woman, I hear as I get older, it’s really important to keep incorporating strength training, so it’s something I try to focus on. Can you talk about why it is particularly important for women? 

[Dr. Hennessey]

Yeah, especially women, and especially as women get older and are getting into the menopausal range or perimenopausal range, our estrogen levels drop. Estrogen is really important in making sure calcium gets into our bones to keep the bones strong. And as our estrogen levels drop as we become older, there’s a lower rate of calcium movement into your bones, and the risk of injury is higher of those bones. Your muscles are what are surrounding those bones, and by strengthening our muscles, we’re, we’re protecting it. Secondly, impact, meaning standing or movement of your bones, triggers the body to send more calcium. And so, by doing that, you’re countering some of the natural progression of our bodies by sort of saying, “No, no, you need more calcium in those bones.” And so it’ll do it kind of via a different mechanism than it did previously. 

[Courtney]

That’s incredible. So, if I’m lifting weights, I’m helping my bones. 

[Dr. Hennessey]

Mm-hmm. 

[Courtney]

That’s very motivating. 

[Dr. Hennessey]

Yeah. Exercise helps everything. 

[Courtney]

What advice do you have to encourage people to make exercise a part of our lives? It’s hard when we’re busy and tired, and there’s a lot going on in life. 

[Dr. Hennessey]

I think number one is pick something you like, and once you’ve done that, then get yourself into a routine. The routine piece of this is key, where it’s weird if you don’t exercise that day, rather than weird if you do. 

[Courtney]

I love that. 

[Dr. Hennessey]

And that’s, I think, where, if we’re gonna start somewhere, where this kind of idea of cozy cardio comes into play. It doesn’t have to be something all crazy dramatic. You can go say, “Okay, I, I got 20 minutes. I’m gonna take a walk.” That’s it. 

[Courtney]

Yeah, just make it part of your life. 

[Dr. Hennessey]

I think getting yourself motivated to start comes from small things, not big things. A big, full change of your lifestyle in every way, that’s not sustainable, right? It’s all about making it incorporate into your own lifestyle, and everyone’s definition of that is different. 

[Courtney]

So, we set out to answer the question: Can I improve my heart health without high-intensity workouts? And it seems like the answer is yes. 

[Dr. Hennessey]

100% you can. That’s, I think, the key to all of this is any movement is good movement. You see these small benefits that become much bigger benefits over time, and that’s really where it’s incorporated into your routine, and you’re improving your heart and physical health. 

[Courtney]

Thank you so much, Dr. Hennessy. I can’t wait to go do some cozy cardio after this conversation. 

[Dr. Hennessey]

Totally. It’s freezing outside. Definitely- it’s definitely- 

[Courtney]

Stay inside. 

[Dr. Hennessey]

… cozy cardio day today. 

[Courtney]

Our many thanks to Dr. Jessica Hennessy. I’m Courtney Allison.  To learn more about Dr. Hennessy’s work with patients, check out the show notes. Join us next time when we discuss how diet can improve your heart health numbers. That’s in two weeks, right here on Health Matters. Health Matters is a production of NewYork-Presbyterian. The views shared on this podcast solely reflect the expertise and experience of our guests. NewYork-Presbyterian is here to help you stay amazing at every stage of your life. To get the latest episodes of Health Matters, be sure to follow and subscribe on Apple Podcasts, Spotify, or wherever you get podcasts.