Guide
Incline treadmill walking: the 12-3-30 workout and gentler intervals
Walking uphill on a treadmill turns an easy walk into a real workout, without running. Here's what the popular 12-3-30 routine is, why it's a lot for most people on day one, and a gentler incline interval plan to build up with.
What is the 12-3-30 workout?
It's a treadmill walk at a 12% incline, at 3 miles an hour (about 4.8 km/h), for 30 minutes. It went viral because it's simple and it really gets your heart going: walking up a steep hill works your legs and lungs much harder than walking on the flat, at the same speed.
Most treadmills go up to 12 or 15%, so it's near the top for many machines. That's the catch: thirty minutes at 12% is hard if you're new to it.
Build up first: incline intervals
Instead of a steady steep climb, alternate hills and flats. Short climbs, easy recoveries, and you can make each hill a little steeper week by week.
- Warm up, 3 minutes: 2.8 mph (4.5 km/h), 1% incline.
- Climb, 3 minutes: 3.1 mph (5 km/h), 8% incline.
- Recover, 2 minutes: 2.8 mph (4.5 km/h), 2% incline.
- Repeat the climb and recovery six times, then cool down 3 minutes at 2.5 mph (4 km/h), flat.
36 minutes in all. Too much? Use 5% for the climbs, or do four rounds. Easy? Add 1% to each climb next time.
A few weeks to 12-3-30
| Week | Walk | How often |
|---|---|---|
| 1 to 2 | Incline intervals at 5 to 6% | 3 times a week |
| 3 to 4 | Incline intervals at 8% | 3 times a week |
| 5 | 15 minutes steady at 10% | 3 times a week |
| 6+ | 20, then 30 minutes at 12%, 3 mph | 2 to 3 times a week |
Move on only when the week before felt comfortable. There's no prize for getting there fast.
Speeds at a glance
| Feel | mph | km/h |
|---|---|---|
| Easy stroll | 2.5 | 4.0 |
| Steady walk | 2.8 to 3.0 | 4.5 to 4.8 |
| Brisk walk | 3.4 to 3.7 | 5.5 to 6.0 |
| Very brisk | 4.0 | 6.4 |
On an incline, go slower than you would on the flat. Talking in short sentences should still be possible.
Tips for safe incline walking
- Don't hang on to the handrails. If you need them to keep up, lower the incline or the speed.
- Short steps, upright posture, leaning very slightly from the ankles, not the waist.
- Warm up and cool down on the flat, and stretch your calves afterwards.
- Stop if you feel dizzy, short of breath, or have chest pain.
Setting it up in Pace Pulse
Pace Pulse has both plans ready made: Incline Intervals and Incline Climb 30 (12% at 3 mph, with a warm-up and cool-down). Or switch any plan to Treadmill and set the speed and incline for each part.
As each part starts, the coach reads out what to set, like "Fast, 3 minutes. Speed 3.1, incline 8", so you don't have to look at your phone. Speeds follow your units, mph or km/h, and the distance comes from the belt.
Let Pace Pulse time it for you
A free interval walking timer for iPhone, Apple Watch, Android and Wear OS. Ready made plans, gentle walks with rest stops, treadmill plans with speed and incline, voice and haptic cues for every switch, and a custom builder. No ads, no account.
Get Pace PulseQuestions
What does 12-3-30 mean?
A treadmill walk at 12% incline, 3 miles an hour (about 4.8 km/h), for 30 minutes.
Is 12-3-30 good for beginners?
It's hard for most beginners. Start with incline intervals at 5 to 8% and build up over a few weeks. Check with your doctor first if you have a health condition.
What speed is 3 mph in km/h?
About 4.8 km/h.
Can Pace Pulse tell me when to change the incline?
Yes. Treadmill plans have a speed and incline for each part, and the coach reads them out as each part starts.
Pace Pulse is a walking timer, not medical advice. If you have a health condition, are recovering from an illness or injury, or haven't been active for a while, check with your doctor first.