Steady state cardio is a practice we’ve all collectively come to worship as a fitness centerpiece over the years—whether it’s jogging, cycling, swimming, or even using an exercise machine to hold a steady pace and a steady heartbeat for the duration of the workout. But years of endurance athletes experiencing cardiovascular problems has shown us just how dangerous and misleading this belief is: not only does it have adverse health effects, but it also completely discounts the fact that steady state cardio is only one form of cardiovascular exercise. As my upcoming podcast guest Dr. Doug McGuff explains in this video, you can’t isolate “cardio,” because our heart, lungs, musculoskeletal system, and cellular metabolism operate in a much larger paradigm that he refers to as “global metabolic conditioning.” Unfortunately, years of conventional wisdom, and as Dr. John Jaquish says, many “gross misinterpretations of research” winded up obscuring the truth about cardiovascular exercise and the necessity of steady state cardio. In his book, Body By Science, Dr. Doug cites a McMaster University study from 2005 that found, “six minutes of pure, hard exercise once a week could be just as effective as an hour of daily moderate activity.”
At this point, we have seen more than enough evidence of how steady state cardio adversely affects the body, to the point where it seems almost reckless to ignore it. Why engage in what is very likely an inferior and more risky way of working out, when you can instead just go for a variety of explosive workouts that elevate and lower your heart rate in a more sporadic manner? It’s important to consider this, because when you’re engaging in a strength/power workout, or even exercise that is sport-specific, like a tennis match, you are able to develop a variety of other crucial health, fitness, and longevity attributes (such as balance, power, muscle mass, even just having fun!) and skills, while still obtaining incredible cardiovascular benefits. And all it entails is doing brief stints of maximum output, moderate exercises at aerobic heart rates, and recovery exercises where your heart rate is still probably double your resting rate.
These maximum efforts deliver cardiovascular conditioning that is superior to steady-state workouts—ones that last 10 times longer!—but without the risk of burnout associated with chronic steady-state cardio (other risks include: the degradation of mitochondria, decreased ATP production and even a disruption in aerobic metabolism, aka fat burning). As Dr. John Jaquish said on the B.Rad podcast, “We are not meant to exert ourselves with that much intensity for very long.” In the fantastic talk,There’s No Such Thing As Cardio,James Steele explains the risks that come with working a muscle to fatigue: “As you start to workout maximally, the products of anaerobic metabolism cannot enter the mitochondria as quickly as they would like to. They start to stack up in the cell, and something’s gotta be done with them…So they get converted to lactate, which starts to interfere with muscular performance and contraction.”
In my article Rethinking Cardio, I quote Dr. Peter Attia to highlight the cardiovascular risks that result specifically from doing chronic steady-state cardio: “Challenging endurance workouts cause an increase in both heart rate and stroke volume [amount of blood pumped out per beat of the heart], by stretching the heart larger to pump more blood per beat. This amazing organ can quickly go from pumping three to five liters of blood around our body per minute at rest to 30 liters per minute during very intense exercise. Unfortunately, the right side of the heart, which pumps only against the low-resistance lungs, and is far less muscular than the left ventricle, is more vulnerable to damage from chronic amounts of high cardiac output training. So while short bouts of this intensity don’t appear to cause lasting damage on the heart, prolonged activity does—at least in susceptible individuals. The so-called chronic cardio patterns can cause the right ventricle to become scarred from excessive use and insufficient recovery. This scarring can lead to cardiac arrhythmias, especially atrial fibrillation, and even sudden death in athletes who have no evidence of atherosclerosis.”
Engaging in a pattern of chronic, steady state cardio also puts you at risk for more than just serious cardiovascular damage: it can cause a huge tank in male hormones, prompt muscle catabolism, promote fat storage, and even suppress immune function! Therefore, learning and understanding the science behind the way our bodies react to steady state cardio is an effective and important step in anyone’s fitness journey, regardless of if you’re an athlete or not: it illuminates the severity of the risks associated with this practice. Which of course, prompts one to ask: are there even any legitimate reasons left for doing steady state cardio? The only reasons I can see are:
1). If you genuinely enjoy getting out there and spending time in nature (or on the Stairmaster in the gym while you’re watching TV) as a nice break from sedentary modern life.
2). If you are doing it correctly, performing the vast majority of aerobic workouts at or below the MAF heart rate model of 180 minus age in beats per minute.
3). If you are training for a specific athletic goal, such as a marathon or a triathlon.
Do any of these three options apply to you? If they don’t, and you’re still thinking steady state cardio is absolutely essential for all around health, fitness, and longevity, then please consider this: you’ll likely get vastly more return on investment from simply moving around more each day and then performing brief, explosive strength training or sprinting sessions. Being capable of performing magnificent endurance feats once in a while is great, but it doesn’t mean that we should do them all the time, and certainly not for the duration most of us had gotten used to thinking was normal!
For more information and additional resources, check out Cardio Does Not Exist and Body by Science from Dr. Doug McGuff, James Steele’s talk, There’s No Such Thing As Cardio, and Dr. John Jacquish’s book Weight Lifting Is a Waste of Time, as well as his B.Rad podcast episode, Smashing Fitness Falsehoods, Getting Super Ripped Without Weights, and Pushing the Extremes of Healthy Living.