Trending workout
The 12-3-30 Workout, Explained
It went viral for being almost too simple: incline, speed, time. Here's whether the 12-3-30 treadmill workout actually delivers — and how to do it without wrecking your knees.
The formula
- 12 — incline percentage
- 3 — speed (mph ≈ 4.8 km/h)
- 30 — minutes
Does it work?
Yes, as cardio. It burns roughly 250–350 calories a session, raises your heart rate into a fat-friendly zone, and is low-impact. But it only "works" for fat loss inside a calorie deficit — no workout out-runs the kitchen.
Start easier: if 12% incline feels brutal, begin at 6–8% and build up. Hold the rails only for balance, not to lean.
Who it's great for
- Beginners who want steady, joint-friendly cardio
- Anyone bored of flat walking
- Pairing with weights — it's perfect Zone 2 cardio
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