Imagine a leisurely bike ride through the park on your way home from work. Now picture a run on a treadmill, sweat dripping down your neck as you swig from a water bottle. Surely, one of these two activities must be “better” for your health.
Not so fast. When we compare the exercises we engage in, including cardio, there’s a lot to consider. Cycling has also emerged more definitively as a way to reduce the risk of mortality and avoid heart disease, among other benefits — but is it really as good as other forms of exercise?
Under the same conditions, one form of cardio might burn more calories than another. But humans don’t exercise in labs, and our physical outcomes may vary depending on how long we choose to exercise, how often, and with what intensity. More than that, there are benefits to cycling that can’t be measured as easily.
How do running and cycling compare?
Generally, exercise researchers compare different forms of exercise by having the same person perform them at the same intensity level for the same amount of time. There are a few ways to measure intensity, but one of them is heart rate, Mathias Ried-Larsen tells Inverse. Larsen led a study published recently in JAMA Internal Medicine about the effects of cycling on mortality for people with diabetes. He’s also an associate professor of exercise epidemiology in sports science and clinical biomechanics at the University of Southern Denmark.
Whether biking, running, or swimming, “It’s intensity-dependent,” Larsen says. “So when you compare these kinds of exercises, if you match for intensity, they would do equally as well.” He did add, however, that running engages more muscle mass than biking, which would mean that all other things equal, running might burn slightly more calories.
“But I would guess from a health point of view that the difference would be negligible,” he says.
Indeed, a 10-minute HIIT (high intensity interval training) cycling workout achieved what a less intense 30-minute continuous exercise could, an author of a recent study in the journal Medicine & Science in Sports & Exercise told Inverse.
Another measurement of intensity is VO₂ max, or the maximum rate of oxygen your body can use in exercise. The higher your maximum VO₂ is, generally, the more oxygen your body is processing at its limit and the more endurance you have. One review of studies that included a comparison of triathletes who were either trained cyclists or runners noted that runners typically achieved a higher VO₂ max while running on a treadmill compared to cycling on a standing bike.
Cyclists, on the other hand, could reach the same VO₂ max with both activities. However, cycling never achieved a higher oxygen consumption level than running. The research isn’t yet conclusive, but it seems that cycling could be just slightly less intense for the body than running — at least in a lab.
There’s also evidence to suggest that running, unlike lower-impact cardio, can cause more stress on bones and joints. Another review notes that runners can sometimes have a higher risk for low bone density and stress injuries if they run on hard surfaces or increase intensity abruptly. As cycling isn’t “weight-bearing,” it’s easier on the knees, according to Harvard’s health newsletter.
Exercise only works if you ... just do it.
So if we go back to the starting scenario, a low-key bike ride compared to a high-intensity run, the run would win — that is, if you did both for the same amount of time or chose to do one or the other in the first place.
“It is all about if you do it, and it's all about the intensity,” says Larsen. “So if you do low-intensity swimming, compared to moderate-intensity cycling, then cycling would win.” But it doesn’t matter how intense your cardio is if you only hit the gym once a year. That’s where cycling has an advantage: it doubles as a way to get from place to place.
Some physical activity is much better than none. For people who can’t seem to fit scheduled gym time into a schedule, he advises:
“If it's a matter of, you're not doing exercise at all, cycling would be a good option to try to get some exercise or physical activity into your everyday life.”
In fact, the health benefits of cycling to work compared to high-intensity scheduled exercise aren’t always vastly different. In one study of 188 inactive adults, those instructed to bike to work five times a week improved their insulin sensitivity by 20 percent.
In contrast, others that did vigorous exercise five times a week to burn the same amount of calories improved theirs by 26 percent. It’s a difference, but not a huge one. Everyone who exercised improved their cardiorespiratory fitness and lost fat mass.
What are the other benefits of cycling?
Then there are the aspects of exercise that are harder to quantify. Larsen says that setting aside time to go to a gym or pool takes extra effort and time. “In many countries, at least, you might be more prone to do something that you could fit in as a daily activity,” he says.
There’s even a category for the kind of activity that kills two birds with one stone: Non-Exercise Activity Thermogenesis (NEAT) or incidental physical activity (as opposed to intentional). This is the exercise you do without thinking about it - lifting boxes, running errands, chasing a pet around. Chances are, you’re more likely to engage in exercise of any kind - including cardio - if it’s fun or has another purpose besides “fitness.”
What’s more, cycling gets you out in nature, is a sustainable means of getting from point A to point B, and could reduce a significant portion of carbon emissions globally. Even the World Health Organization recently kicked off an effort to double cycling by 2030. Studies show again and again that spending time outdoors is good for both mental and physical health. Cycling instead of driving can save you the thousands of dollars you might spend on gas. And maybe best of all, cycling is COVID-safe.
That’s enough of a motivation as any to (safely) race your friend to the park by bike instead of driving to the gym.