The 12-3-30 workout, honestly

Short answer

The 12-3-30 workout is 30 minutes of treadmill walking at a 12% incline and 3 miles per hour. A 2025 study found it burned about the same calories as a shorter self-paced run, with a larger share of energy from fat. It is hard, so most people should start lower and build up.

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First two rounds free · teams of 2–4 · a new round every Tuesday

By Coach Josh · Get Your BMR

2 sources · Reviewed October 29, 2026

The short version

  • 12% incline, 3 mph, 30 minutes
  • About the same calories as a shorter run in one study
  • Start lower and build up
Illustration: a woman walking slowly on an under-desk walking pad at a home standing desk.

Free interactive tool

Build a gentle three-day plan

Start from a walk that feels easy today and build up from there.

Where 12-3-30 came from

Lauren Giraldo posted the workout on YouTube in 2019, and it went viral on TikTok in 2020. The name is the recipe: 12% incline, 3 miles per hour, 30 minutes.

What the study found

A 2025 study at the University of Nevada, Las Vegas compared 12-3-30 with a self-paced run in 14 young, active adults. Calories were about the same: roughly 308 for 30 minutes of 12-3-30 and 310 for about 24 minutes of running.

During 12-3-30, a larger share of energy came from fat (about 41% against 33%). That is the fuel used during the workout, not fat lost from the body, which depends on your whole day.

Is 12-3-30 good for women over 40?

The study tested 14 young, active adults, so it doesn’t tell us how 12-3-30 works for women over 40. A steep incline can be hard on calves, shins and the lower back at first. Shorter sessions at a lower incline are still good walking, and they count toward your weekly minutes.

On a walking pad

Most walking pads have no incline. Walk at a brisk pace you can keep up instead; the minutes still count toward the 150 a week that U.S. guidelines suggest.

Walk it with a team this week

Join a team of 2–4, walk & drink your water Tuesday to Thursday, and see the winners Friday.

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First two rounds free · teams of 2–4 · a new round every Tuesday

The 3-Day Walk & Water Challenge

How a round works

  1. 1. Join a team

    Two to four of you on one team: a friend’s, your own, or one you join in the app. Your team gets a name, a crest & a spot on the live leaderboard.

  2. 2. Walk + water, 3 days

    Tuesday, Wednesday & Thursday. A step goal & a water goal sized to where you are today. The board updates as you walk & closes Thursday at midnight, Arizona time.

  3. 3. Friday winners

    Friday morning the results go up. The winning team’s card glows gold, badges land beside names on the board, and a new round starts Tuesday.

Bigger isn’t better. Teams rank on their AVERAGE.

A team’s score is its average per woman, not its total. So two friends can beat a team of four, and every walker’s day counts the same. When one of you goes quiet, the others notice & send a nudge in team chat.

The Walk & Water team card: team name and crest, team level, the average steps per woman, and each teammate’s steps and glasses of water.
Your team card. The big number is the average per woman.
The Walk & Water leaderboard: your rank this week, steps, glasses of water, day streak, and the 3-day challenge rankings.
The live leaderboard. Solo, team & global ranks for this round.

How to build up to 12-3-30

Use the plan builder above to start from a walk that feels easy today.

  1. Start lower

    A coaching suggestion: try a 4–6% incline at a pace you can talk at, for 10–15 minutes.

  2. Add one thing at a time

    Raise the incline or the minutes each week, not both at once.

  3. Keep your hands off the rails

    Holding on makes it easier than it looks. Slow down instead.

Questions

What does 12-3-30 mean?

12% incline, 3 miles per hour, 30 minutes on a treadmill.

Is 12-3-30 better than running?

In one small study it burned about the same calories as a shorter run, with a larger share from fat. Neither is better for everyone; pick the one you can keep doing.

How many calories does 12-3-30 burn?

About 308 in 30 minutes for the young, active adults in the 2025 study. It depends on your weight and fitness.

Can beginners do 12-3-30?

A coaching suggestion, not a study finding: start lower, around a 4–6% incline for 10–15 minutes, and build up slowly.

Sources

Written by Coach Josh and checked against these sources on October 29, 2026. General information, not medical advice.

Show all 2 sources
  1. Wong et al. (2025). The 12-3-30 treadmill workout compared with self-paced running. International Journal of Exercise Science
  2. U.S. Department of Health and Human Services — Physical Activity Guidelines for Americans, 2nd edition
Coach Josh

Who writes these guides

Coach Josh

Professional trainer since 2018 · ISSA & NCCPT certified · Creator of Get Your BMR & the Walk & Water Challenge (BodyByReason)

I’m Josh. I built Get Your BMR so you could see what your body burns at rest, & I built Walk & Water so you’d have somewhere to use it with people who notice when you show up.

I walk every round too: same board, same three days, on my own team. I don’t always win. Tap Chat with Coach in the app & it’s me who answers.

About 7 in 10 women who finish a round come back & play the next one.

Walk & Water app data, 73 finishers, snapshot October 19, 2026.

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Related guides

Get Your BMR is Coach Josh’s free calculator. The 3-Day Walk & Water Challenge is where you put the number to work, and it runs inside the APEX: Walk & Water app on iPhone and Android.