WalkPace ProIt's a fair question, and one I get asked a lot: if I'm already out walking every day, why bother speeding up and slowing down? Does changing my pace actually burn more calories, or is it just something fitness people say?
The short version: yes, interval walking does burn more calories than strolling at one steady speed, but probably not for the reason you'd guess, and the calorie gap on its own is smaller than the internet would have you believe. The more interesting story is what happens to your heart, your fitness, and your blood sugar over the following weeks. Let's walk through what the research actually found.
First, the calorie question
Here's the finding that surprises people. Engineers at Ohio State put walkers in a motion-capture lab and measured what it costs, energy-wise, to change speed. Not to walk fast, but to keep shifting gears. They found that varying your pace can burn up to 20% more calories than holding a single steady speed, and that as much as 8% of the energy we use in everyday walking comes purely from the act of starting and stopping.1
That's the part most calorie calculators miss. Speeding up means accelerating your body mass, and every acceleration is work your legs have to do. A treadmill set to one unchanging speed hides that cost. Real-world walking, and interval walking especially, is full of it.
There's a second, smaller contributor too: the "afterburn," or EPOC (excess post-exercise oxygen consumption), the extra oxygen your body uses recovering after you stop. When researchers matched interval and continuous exercise for total energy and compared them head-to-head, the interval version produced a somewhat higher afterburn.2 It's real, but keep expectations grounded: for moderate exercise the afterburn typically adds only something in the range of 6–15% on top of what you burned during the session, not a hidden second workout.
The comparison at a glance
| Steady-pace walking | Interval walking | |
|---|---|---|
| Calorie burn | Solid, predictable | Modestly higher for the same time, thanks to speed changes1 |
| Aerobic fitness | Small gains | Markedly larger gains (~9% higher peak capacity)3 |
| Blood pressure | Little change | Meaningful drop in systolic pressure3 |
| Leg strength | Maintained | Measurable improvement3 |
| Blood sugar control | Prevents decline | Better, even at matched calorie burn4 |
| Effort required | Low, comfortable | Comes in waves: hard, then easy |
Where interval walking pulls ahead: cardiovascular fitness
This is the finding that made interval walking famous. In a landmark trial out of Shinshu University in Japan, researchers took 246 middle-aged and older adults (average age 63) and split them into three groups: no training, steady moderate-pace walking, and interval walking, which meant three minutes brisk, three minutes easy, repeated for about 30 minutes.3
Same time on their feet, very different results
After five months, the interval walkers came out clearly ahead of the steady-pace group: roughly a 9% greater rise in peak aerobic capacity, a larger drop in systolic blood pressure (on the order of 9 mmHg), and measurable gains in thigh strength. The steady-pace walkers improved far less, despite spending the same amount of time walking.3
The logic is almost obvious once you see it. Comfortable walking asks very little of your cardiovascular system, so it doesn't have much reason to adapt. The brisk intervals push your heart and lungs into a zone where they're forced to get stronger, and the easy intervals let you recover just enough to do it again. Over half an hour you rack up far more time at a genuinely challenging intensity than you ever could by trying to "walk fast" the whole way.
The long game: blood sugar and metabolic health
Calorie burn is a one-day story. The changes that matter most for long-term health show up over weeks, and this is where the interval-vs-continuous comparison gets really pointed, because researchers deliberately controlled for calories.
Better results even when calories were held equal
In a randomized trial, adults with type 2 diabetes did either interval walking or continuous walking, with both groups matched for total energy expenditure. Interval walking came out ahead on physical fitness, body composition, and free-living blood sugar control measured by continuous glucose monitors. Continuous walking mostly just held the line against decline. Same calories burned, better metabolic outcome from the intervals.4
That "matched for energy expenditure" detail is the whole point. It tells you the advantage isn't coming from burning a few extra calories. It's coming from how you burned them. Repeatedly challenging your muscles and then recovering seems to change how your body handles glucose in a way that a steady stroll doesn't. A 2024 review pulling the research together reached the same broad conclusion: the benefits of interval walking are well established across older adults, sedentary people, and those managing type 2 diabetes.5
So, which should you do?
If the honest answer to "which burns more calories" is "interval walking, by a modest margin," the more useful answer is this: interval walking gives you noticeably more health per minute. More cardiovascular fitness, better blood pressure, more strength, and better blood sugar control, often for the very same time investment you're already making.
None of which means regular walking is a waste. It absolutely isn't. Any walking beats the couch, and a steady walk is wonderful for your mood, your joints, and your day. But if you've got 30 minutes and you want the most return on them, the research keeps pointing the same direction: vary your pace.
The catch is that intervals require you to actually keep time, three minutes brisk then three minutes easy, and nobody wants to stare at a stopwatch mid-walk. That's the entire reason we built WalkPace Pro.
Let the intervals run themselves
WalkPace Pro plays gentle audio cues over your music or podcast, so you always know when to pick it up and when to ease off, with no clock-watching required. Set your time, press start, walk.
Try WalkPace ProiPhone & Apple Watch · One-time purchase, no subscription
References
- Seethapathi N, Srinivasan M. "The metabolic cost of changing walking speeds is significant, implies lower optimal speeds for shorter distances, and increases daily energy estimates." Biology Letters, 2015. Summary via The Ohio State University College of Engineering: engineering.osu.edu
- Matsuo T, et al. "Effect of interval exercise versus continuous exercise on excess post-exercise oxygen consumption during energy-homogenized exercise on a cycle ergometer." Journal of Exercise Science & Fitness, 2019. ncbi.nlm.nih.gov
- Nemoto K, Gen-no H, Masuki S, Okazaki K, Nose H. "Effects of High-Intensity Interval Walking Training on Physical Fitness and Blood Pressure in Middle-Aged and Older People." Mayo Clinic Proceedings, 2007. mayoclinicproceedings.org
- Karstoft K, Winding K, Knudsen SH, et al. "The effects of free-living interval-walking training on glycemic control, body composition, and physical fitness in type 2 diabetic patients: a randomized, controlled trial." Diabetes Care, 2013. ncbi.nlm.nih.gov
- "Health benefits of interval walking training." Applied Physiology, Nutrition, and Metabolism, 2024. cdnsciencepub.com
This article is for general information and isn't medical advice. Check with your doctor before starting a new exercise routine, especially if you manage a health condition.