Is Cardio Bad for You?

Published September 07, 2019
Ben Kissam

Written By: Ben Kissam, BS

Ben has a B.S. in Movement and Sports Science and over 7 years Certified Personal Training Experience.

<article> <div> <ul> <li><a href="#section1">Is Cardio Bad for You?</a></li> <li><a href="#section2">What Happens If You Overdo Cardio?</a></li> <li><a href="#section3">Is Too Much Cardio Bad for Your Heart?</a></li> <li><a href="#section4">How To Do Cardio Smarter With HIIT</a></li> <li><a href="#section5">The Bottom Line</a></li> </ul> </div> <section> <p>A 30-minute <a target="_blank" href="" rel="noreferrer">walk</a>, run, or swim a few days a week seems like a perfectly good exercise routine. But in recent years, some experts have called into question whether this type of cardio is a help or a hindrance to your fitness goals, while others say it stands the test of time. With so many conflicting reports, it’s hard to know what to believe!</p> <p>We’re here to clear up some of the misconceptions about cardio that are out there. Stick around and we’ll show you how to <a target="_blank" href="" rel="noreferrer">lose weight</a> and gain strength by doing cardio smarter, not harder!</p> </section> <hr class="divider-50 divider-medium mx-auto"> <section> <picture class="lazy-load"> <source data-srcset="" type="image/webp"> <source data-srcset="" type="image/jpf"> <source data-srcset=""> <img src="" class="img-fluid" alt="chart-data-desk-pen-graph"> </picture> </section> <section id="section1"> <header>Is Cardio Bad for You?</header> <p>Let’s start with a clarification: what exactly do we mean when we say ‘cardio’?</p> <p>Most of us think of <a target="_blank" href="" rel="noreferrer">cardio</a> as swimming laps, riding a bike, running on the treadmill, and similar activities. But this is just one specific type of cardio known as steady-state cardio. We’ll tell you more about another type—high-intensity interval training—in a minute. For now, let’s focus on steady-state cardio. </p> <p>This type of cardio is popular because of its many proven health benefits. </p> <p>For one, your regular cardio session boosts your heart health. It strengthens the heart muscle to help it pump blood more efficiently <sup>1</sup>. It also raises HDL—‘good’ cholesterol—and lowers LDL—‘bad’ cholesterol which keeps your arteries clear <sup>1</sup>. And it’s been shown to reduce blood pressure, particularly in older sedentary folks<sup>2</sup>. All of these things mean a healthy heart and a lower risk of heart disease.</p> <p>Cardio is also a useful tool in weight management. Since it requires so much energy to propel you around the track or pool, cardio burns a lot of calories. Cardio can also reduce blood sugar and increase insulin sensitivity over time, which can be especially helpful for people with type 2 diabetes <sup>3</sup>. </p> <p>Doing cardio has a positive impact on your overall well-being. It can improve sleep quality, ease depression and anxiety, boost your mood, and even enhance your mental functioning <sup>1</sup>.</p> <p>So no, of course cardio isn’t ‘bad’ for you. In fact, our ability to run for long periods of time is one of the things that distinguishes us from our furry primate cousins. We were practically made for this type of exercise.</p> <p>But we start to run into trouble when we assume that because cardio has these important benefits, more must be better. </p> </section> <hr class="divider-50 divider-medium mx-auto"> <section> <picture class="lazy-load"> <source data-srcset="" type="image/webp"> <source data-srcset="" type="image/jpf"> <source data-srcset=""> <img src="" class="img-fluid" alt="adult-athlete-woman-sit-drinking-water"> </picture> </section> <section id="section2"> <header>What Happens If You Overdo Cardio?</header> <p>The truth is, too much cardio can actually hinder your strength gains and cause you to hold on to fat. That might sound crazy, but there’s scientific evidence to back it up. </p> <p>Your body responds to exercise the same way it responds to other forms of <a target="_blank" href="" rel="noreferrer">stress</a>—by activating the fight or flight response. This leads to a spike in the ‘stress hormone’ <i>cortisol</i> which sets off reactions in the body to give you quick energy. That’s exactly what you need to get through a cardio session.</p> <p>But one of the main ways cortisol helps you get that energy is by breaking down protein from your muscles to turn it into glucose it can use for energy <sup>4</sup>. That means that long bouts of cardio can actually cause you to lose muscle rather than build it. On top of that, cortisol decreases testosterone levels, one of the main drivers of muscle growth in both men and women.</p> <p>These effects are important because muscle mass impacts your metabolism and how your body burns fat. The more muscle you have, the higher your metabolism and the more calories you naturally burn each day. It’s especially important when you consider that, over the long term, cortisol actually encourages the body to store <a target="_blank" href="" rel="noreferrer">fat</a>.</p> <p>Unfortunately, it’s not just during exercise where obstacles crop up. A lot of us are doing the same steady-state cardio routine several days per week, often based on the national guidelines that recommend 150 minutes of moderate exercise weekly. That’s a lot of time!</p> <p>Our bodies need rest in order to recover and build <a target="_blank" href="" rel="noreferrer">lean muscle</a>. Doing a lot of long workouts every week can keep your cortisol levels high which means all of those effects that are helpful in the short term stick around. In addition to breaking down muscle and retaining fat, cortisol suppresses the immune and reproductive system, causes inflammation, and raises blood pressure and blood sugar <sup>4</sup>.</p> <p>All of these things can hinder your progress toward your weight loss and fitness goals. But too much cardio can’t actually be dangerous, right?</p> </section> <hr class="divider-50 divider-medium mx-auto"> <section> <picture class="lazy-load"> <source data-srcset="" type="image/webp"> <source data-srcset="" type="image/jpf"> <source data-srcset=""> <img src="" class="img-fluid" alt="adult-man-chest-pain-heart"> </picture> </section> <section id="section3"> <header>Is Too Much Cardio Bad for Your Heart?</header> <p>Recent research has shown some evidence that overtraining can have detrimental effects on your heart health. </p> <p>Surprisingly, a 2017 study published by the Mayo Clinic found that people who trained three times more than the national physical activity guidelines had a 27 percent higher chance of coronary artery calcification—a predictor of heart disease—than those who exercised the <i>least</i> <sup>6</sup>. And yes, you read that right!</p> <p>The Million Women Study found that women who performed daily strenuous activity—as opposed to moderate activity—had a higher risk of heart disease, blood clot complications, and stroke <sup>6</sup>. </p> <p>Still, these effects only show up at the absolute extremes in people like elite athletes and marathoners. The majority of us don’t need to worry about exercising to the point of causing heart damage. In fact, as we showed before, we can expect quite the opposite!</p> </section> <hr class="divider-50 divider-medium mx-auto"> <section> <picture class="lazy-load"> <source data-srcset="" type="image/webp"> <source data-srcset="" type="image/jpf"> <source data-srcset=""> <img src="" class="img-fluid" alt="abdominal-exercise-adult-group-women"> </picture> </section> <section id="section4"> <header>How to Do Cardio Smarter with HIIT</header> <p>We’ve talked about the downsides of your run-of-the-mill steady-state cardio, but you’re probably wondering: what’s the alternative?</p> <p>Our answer: high-intensity interval training (HIIT). This is a popular workout method where you do a <a target="_blank" href="" rel="noreferrer">circuit</a> of exercises. Each move is done at high intensity for a short time, followed by a period of rest. Because you can expend just as much energy from those few short bursts as you do during long stretches of cardio, these routines are usually quick and effective.</p> <p>Doing a HIIT routine also releases cortisol into your system, but as we mentioned before, sometimes cortisol is exactly what you need to power you through a <a target="_blank" href="" rel="noreferrer">workout</a>. It’s how you regulate that cortisol that makes all the difference. </p> <p>HIIT <a target="_blank" href="" rel="noreferrer">workouts</a> take much less time than regular cardio which means your body spends less time under stress. The short span makes it much easier for your body to return to its normal cortisol levels when the workout is done, and ensures that you won’t have any of those negative effects of ongoing high cortisol levels. </p> <p>A HIIT session does something interesting to your metabolism, too. Imagine your metabolism on steady-state cardio: it’s a low, slow-burning flame that flickers out as soon as the workout is done. Now imagine each HIIT interval as a little gasoline added to the flame. Each interval revs up your metabolism more, and the effect lingers hours after your workout is done <sup>5</sup>. Even if you overdo it on food after your workout, your metabolism can compensate.</p> <p>Plus, our HIIT programs are all about <a target="_blank" href="" rel="noreferrer">functional</a> strength training. Each of our workouts consists of exercises to build strength and increase mass across all of your <a target="_blank" href="" rel="noreferrer">whole body</a>. An hour on the treadmill might make you better at running, but a HIIT routine can help build <a target="_blank" href="" rel="noreferrer">strength</a> to do all of your everyday activities more easily. </p> <p>And of course, strength <a target="_blank" href="" rel="noreferrer">training</a> can increase muscle mass to kick your fat-burning metabolism into high gear. HIIT gives you all of the same great benefits of a cardio routine while avoiding a lot of the pitfalls—like holding onto fat and experiencing fatigue—that steady-state cardio brings up. </p> </section> <hr class="divider-50 divider-medium mx-auto"> <section id="section5"> <header>The Bottom Line</header> <p>Here’s the thing: <a target="_blank" href="" rel="noreferrer">cardio</a> isn’t bad. It’s a great tool for burning calories, building endurance, and getting in better shape. The point to remember is that just because some cardio is good for you doesn’t mean that more cardio is even better. As we’ve seen here, that thinking can even lead you to backslide on your fitness goals.</p> <p>The key is to do cardio <i>smart</i>. HIIT workouts take as little as ten minutes and offer you functional, effective strength training. And in our books, that makes adding HIIT workout routines a great choice!</p> <div class="sub-head">Resources</div> <ol> <li><a target="_blank" href="" rel="noreferrer">What Are the Benefits of Aerobic Exercise?</a></li> <li><a target="_blank" href="" rel="noreferrer">Controlled aerobic exercise training reduces resting blood pressure</a></li> <li><a target="_blank" href=",,20929224,00.html" rel="noreferrer">The Real Reason You're Not Losing Weight</a></li> <li><a target="_blank" href="" rel="noreferrer">All About Cortisol</a></li> <li><a target="_blank" href="" rel="noreferrer">Is High-Intensity Interval Training that Much Better Than Cardio?</a></li> </ol> </section> </article>

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