How Many Calories Does Interval Walking Burn?

1. The calorie arithmetic for your weight and time

Every calorie figure on this page comes from our own MET arithmetic—the same server-side path our calculators and workout log use to estimate active energy when no heart-rate or wearable measurement is present.

A MET (Metabolic Equivalent of Task) is the energy cost of an activity relative to sitting quietly, where 1 MET is defined by convention as 3.5 mL of oxygen per kilogram of body weight per minute (Jetté et al., 1990). Converting oxygen uptake into kilocalories gives the standard equation:

In our exercise catalog, walking movements (Walking, Brisk Walk, Treadmill Walk, Incline Treadmill Walk) sit in the walking category at 3.5 METs, grounded in the Adult Compendium of Physical Activities (Ainsworth et al., 2011; Herrmann et al., 2024). Applying that 3.5-MET coefficient across body weights and session lengths produces the table below:

2. Why people are searching: the 2007 Japanese Interval Walking study

Most searches for interval-walking calorie burn trace back to the viral "3-3 walking workout" (or Japanese Interval Walking Training), which cites a 2007 trial from Shinshu University by Nemoto et al. published in Mayo Clinic Proceedings.

The paper is real, peer-reviewed clinical research—and it is cited here strictly as context for why the protocol is popular, never as evidence for a calorie-burn or weight-loss figure. In fact, Nemoto et al. (2007) measured isometric knee extension and flexion strength, peak aerobic capacity, and resting systolic blood pressure. It measured nothing about calories burned or weight loss, so it cannot support a calorie or weight claim.

Three things the viral trend gets wrong about its own source

• The published order is slow first, then fast: Participants walked for 3 minutes at low intensity (40% of peak aerobic capacity for walking) followed by 3 minutes at high intensity (above 70% of peak aerobic capacity for walking), repeated. The popular "3 minutes fast / 3 minutes slow" summary states the protocol backwards.
• The intensities are the substance, not the 3-minute clock: Each participant’s peak aerobic capacity for walking was measured first with a graded walking test, and their 40% and >70% effort zones were monitored by a triaxial accelerometer that beeped to keep them on target. Walking slightly faster for three minutes without reaching that aerobic threshold is not the protocol tested in the paper.
• The volume was "5 or more" sets on "4 or more" days a week: Participants were instructed to complete 5 or more 6-minute sets per session (at least 30 minutes) on 4 or more days per week. Five sets and four days were minimum floors to clear, not an exact ceiling.

Whose result the 2007 study actually is

The trial enrolled 246 middle-aged and older adults (60 men and 186 women) with a mean age of 63 ± 6 years over a 5-month study period. Improvements in knee strength, peak aerobic capacity, and blood pressure observed in 63-year-old adults over five months do not transfer unqualified to a 28-year-old lifter.

3. How walking burn fits into your daily deficit

A 30-minute walk at 3.5 METs for a 75 kg (165 lb) person adds 138 kcal to the "Out" side of the day’s ledger—or 552 kcal across four 30-minute sessions in a week. Over a full 60-minute session (10 sets), the same 75 kg walker expends 276 kcal in our arithmetic.

Whether those calories move the scale depends on the rest of your energy balance equation:

Walking is valuable for fat loss not because a single 30-minute session burns an enormous number of calories on its own, but because it raises daily expenditure with minimal recovery cost and without the appetite spike that often follows high-impact cardio. When your food intake is anchored to a realistic maintenance baseline, an extra 138 kcal per walk compounds quietly across weeks.

4. How In & Out Calories tracks the "Out" side

To be completely direct about what our app does and does not do: In & Out Calories does not program interval-walking workouts, and it does not run a 3-minute interval timer.

What the app does is keep both sides of your daily energy balance on one screen:

• Active energy from Apple Health and Health Connect: If you wear an Apple Watch or Android wearable on your walk, the app reads your active energy expenditure and step count directly from Apple Health or Health Connect and folds that burn into your day’s net balance.
• Timed walking in the workout log: If you log a timed walk without a wearable (Walking, Brisk Walk, Treadmill Walk, or Incline Treadmill Walk), the app estimates the session using the exact 3.5-MET arithmetic shown on this page for your current body weight and duration.
• Calories In alongside Calories Out: Your walking and lifting expenditure sit directly beside your logged meals and 7-day weight trend, so you can see whether your daily net deficit matches what the scale is doing.