A few weeks ago, I wrote a piece on how I transformed my body over the course of a year. It focused on what I did in the kitchen, what I did at the gym, and my mindset during the process. The piece has received a fair amount of attention: at the time of this writing, it has 274,000 views, 75,000 reads, 16,400 claps, and 87 comments.
Those comments have covered the full range of possible responses. Most were positive, some were negative. Some thanked me for providing inspiration or useful information. Some shared their view or insights they have gained from their own health and fitness journeys. Some asked questions. The most common question, by far, was
What about cardio? What did you do for cardio?
No one expressly stated why they were asking this question or articulated their view on the role that cardio plays in fitness. I have tried to interpret and respond to each of these comment charitably and have assumed that each comment came from a place of sincerity.
Some probably simply wondered what cardio, if any, I did during the year. Some probably came from a sincerely held belief that that kind of bodily transformation can only be done with cardio. Some may have been gently hinting at their belief that cardio is essential for health.
All of these are valid questions and points and worthy of engagement. But first, I want to address something that I find troubling. The questions seem to be premised on an assumption that all exercise falls into one of two camps — either cardio or resistance training— and that any given form of exercise self-evidently falls into exactly one of these two categories. It’s probably worth investigating this assumption.
What is cardio?
So what is cardio, anyway? Cardio is simply any activity that requires an elevated heart rate and breathing rate to sustain. Our muscles require oxygen to function, so when we start using them hard enough and for long enough, we start breathing faster to get more oxygen into the system and our heart starts beating faster to pump that oxygen out to the muscles for them to use. Anything that engages this process is cardio. It can be climbing a fight of stairs, hiking up a mountain, running a marathon, getting after it on the elliptical, and countless other activities.
Including lifting weights. Lifting weights repeatedly requires a lot of work from our muscles, which means they start demanding oxygen, which means we start breathing faster and our hearts start pumping faster. And as we just saw, that’s cardio.
Anyone who doubts this can easily confirm it by lifting weights and paying attention to their breathing and pulse. If you’re using compound lifts and progressive overload, your body is going to be using lots of muscles more intensively than it ever has before. This requires lots of oxygen and you’ll be huffing and puffing and your heart will be racing to get that oxygen out to the muscles.
My AppleWatch regularly tells me that my heart rate is between 150 and 160 beats per minute while weightlifting. This is well within the target heart rate of activities people think of more traditionally as “cardio.”
But what about…?
There are still plenty of valid points and questions on the topic of cardio versus weightlifting (not to imply that they’re opposed to each other). My point is simply that it’s not as black and white as we may think and that there can be overlap between the two. Below are some thoughts and observations about that overlap.
But cardio is better for your heart and your health, right?
Probably not. As we’ve already seen, weightlifting definitely counts as cardio if you’re doing it at a pace and intensity that raises your heart rate and breathing rate. And there are a lots and lots and lots of studies showing that weightlifting provides benefits to your heart health — probably in excess of the benefits of what is traditionally thought of as cardio.
Cardio for weight loss and weight lifting to gain muscle, right?
Not quite. Since weightlifting is cardio, it’s very effective for weight loss. But with the added bonus of building muscle. Most exercise traditionally thought of as cardio doesn’t build much muscle, at least not like weightlifting does.
It doesn’t really matter if you’re consistent, right?
Of course consistency is important! But so is improvement — pushing our bodies to do more than they were able to yesterday. This is why progressive overload is so important. With most exercises traditionally thought of as cardio, the only reasonable way to engage in progressive overload is to go for longer periods of time. For example, you can go on a longer jog. But at some point, it becomes unreasonable to go for longer jogs — there are only so many hours in the day! But in the weight room, continuing progressive overload is much more achievable without sucking up more and more time. It simply requires adding a little more weight each session or doing an extra rep.
But cardio burns more calories than weightlifting, right?
It depends on a whole lot of factors. But if you’re engaging in progressive overload with weightlifting and aren’t taking too long of breaks, there’s no reason it won’t burn as many calories as a comparable jog. But there’s more. When we workout, our bodies continue burning calories at an elevated rate even after we’re done. Some people call it the afterburn effect. And there’s evidence that the afterburn effect is stronger after weightlifting than after activities traditionally thought of as cardio.
So there’s my answer to the most common question I got. It probably isn’t helpful to think of cardio on one hand the weightlifting on the other hand. I basically just did weightlifting in the gym for a year and got tremendous results. Because it is cardio.