HIIT Count
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Total 00:00
Ready
30
4 rounds · 14 min
Start at14–18 · 1% incline

Sprint interval training: 30 seconds at true maximum effort, then a full four minutes of walking. Few rounds, huge intensity. For experienced runners only.

Runner

Your workout

Sprint interval training (SIT) timer

Sprint interval training uses a few truly all-out 30-second sprints with long recoveries of about four minutes. The effort is short but maximal, so each sprint needs full recovery.

↑ Start the timer

Treadmill settings

StepTimeSpeedIncline
Sprint30s14–18 km/h8.5–11 mph1%
Walk4:005–6 km/h3–3.5 mph0%

Rounds: 4

Why it works

Research from McMaster University and others shows just a few minutes of all-out sprinting a week can improve fitness about as much as much longer moderate sessions. It's one of the most time-efficient workouts there is.

Who it's for

Experienced, healthy runners. True all-out sprinting is very demanding, so build up with 30/90 HIIT first.

Questions

What does all-out mean?

The fastest pace you can hold for 30 seconds. You should be unable to go any faster by the end.

Why is the rest so long?

All-out sprints use energy systems that take minutes to recover. Long rests keep each sprint truly maximal.

Is it safe on a treadmill?

Start below your top speed, use the safety clip, and hold the rails when stepping on and off. Never jump onto a fast belt.

Warm up with 5 minutes of easy walking or jogging first. Stop if you feel dizzy, faint or unwell. If you have a health condition, check with a doctor before starting hard exercise.