This is interesting — InterWalk - Intermittent Walking Training:

Regular walking maintains a steady pace throughout, while interval walking varies intensity levels. Interval walking provides greater cardiovascular benefits, increased calorie burn, and improved fitness gains in less time compared to steady-state walking.

And the app appears to be free …

Via: Dr Ruth Machin newsletter, 11 July 2026.

See also: Health benefits of interval walking training.

@Miraz I wonder if the same thing applies to alternating running and walking.

@skoobz Could be. I looked at the actual study and it seemed to be a few minutes at the walking pace followed by a couple of minutes higher intensity, which probably could be running rather than walking faster.

@Miraz Kinda wondering because a lot of couch to 5K programs start this way. I’ve been thinking about it.

@skoobz Interval training has been around forever. (Because it works.) Recent research has focused excessively on making the intervals really, really short. (I think I saw a 10-minute workout where you spent six seconds at an all-out effort, and then 54 seconds recovering.)

@philipbrewer But you don’t need to do that. Any reasonable variation in intensity is going to produce better health and fitness outcomes than cranking out miles at a fixed pace.

And it doesn’t have to be just cardio. You can alternate between walking and lifting and see similar benefits.

@philipbrewer Beautiful! Thank you for the explanation.