Twelve percent incline, three miles an hour, thirty minutes. The 12-3-30 has been one of the internet’s favourite workouts for years, mostly because it is simple and it works harder than it looks. It is not magic, but it is a very good tool.
What it is good for
An incline walk raises your heart rate a lot without the pounding of running. It works the calves, hamstrings and glutes, and it is easy to repeat several times a week. For lifters it is a near-perfect conditioning session: hard on the heart, gentle on the legs you need for squats.
What it is not
It is not a fat-loss shortcut. Fat loss comes from your overall diet and activity, and the 12-3-30 is one good way to add activity. It also will not build much muscle on its own. Pair it with strength training.
How to build up
- Start at 6–8% incline for 20 minutes.
- Add 1–2% incline or 5 minutes a week.
- Keep your hands off the rails and your steps short.
- Ease off if your shins or lower back complain, and build back slowly.
Sample content General guidance, not medical advice. Check with a doctor before starting a new training, diet or supplement plan if you have a health condition, take medication or are pregnant.
Cardio questions, answered
The questions people ask most about 12-3-30 workout.
How often should I do 12-3-30?
Two to four times a week suits most people, with at least one easy day between if your calves are sore.
Is 12-3-30 good for beginners?
Yes, once you build up to it. Start at a lower incline and a shorter time.
Can I hold the handrails on 12-3-30?
Try not to. Holding on takes much of the load off your legs and makes the workout far easier than it looks.
Does 12-3-30 burn fat?
It burns calories and is easy to repeat, which helps. Fat loss depends on your overall diet and activity, not one workout.
What if I do not have a treadmill?
Walk a long hill or a route with plenty of climbing, or use a step machine at an easy, steady pace.
Keep reading
Zone 2 cardio for lifters: how much, how hard, and where it fits
Cardio2 min read
What zone 2 cardio is, how to find it without a lab test, and how to fit two or three easy sessions around strength training without losing gains.
How to train for your first Hyrox: a 10-week approach
Cardio2 min read
Hyrox is eight 1 km runs and eight workout stations. Here is how to split ten weeks of training between running, strength and the stations themselves.
Rucking for beginners: weighted walking, done right
Cardio2 min read
Rucking is walking with a weighted pack. How much weight to start with, how far to go, and how to build up without wrecking your back or feet.