Cutdown intervals
Intervals that get shorter and faster as the session goes on.
Also called: descending intervals.
Cutdowns front-load volume and back-load speed, so the fastest running happens when you are most fatigued. That ordering is the session: it trains the ability to find another gear late, and it gives you honest feedback about whether your first reps were too fast — if you cannot cut down, you did not start controlled.
The session
Shown at a 4:00 marathon reference — 47 min total, about 7.5 km, including 15 min of quality work.
Warm-up
- 12 min easy (6:43–7:24/km)
- 4 × 20 s strides, jog back between
Main set
- 1000 m @ 4:48/km (5K) — 4:48, 115 s/400 m lap
- 3 min jog
- 800 m @ 4:44/km (5K) — 3:47, 114 s/400 m lap
- 3 min jog
- 600 m @ 4:40/km (5K) — 2:48, 112 s/400 m lap
- 3 min jog
- 400 m @ 4:36/km (3K) — 1:50, 110 s/400 m lap
Cool-down
- 10 min easy (6:43–7:24/km)
Why this session works
Descending distances with slightly rising pace finish the session at 3K effort on tiring legs — top-end aerobic power plus the psychology of finishing fast.
Source: Billat 2001. Training phase: build.
Run it at your own paces
Open the workout generator and enter a recent race time — every rep length, recovery and target pace is recalculated for your fitness, and the session exports to .fit for a Garmin watch.
Frequently asked questions
What is a cutdown intervals?
Intervals that get shorter and faster as the session goes on. Cutdowns front-load volume and back-load speed, so the fastest running happens when you are most fatigued.
How long is this session?
At a 4:00 marathon reference it comes to 47 min and about 7.5 km, of which 15 min is prescribed quality work. The generator scales both to your own paces, so a faster runner covers more ground in the same time.
Who is this workout for?
It is written for the build phase of a marathon build. The distances shown suit a 4:00 marathoner; enter your own recent race time in the generator and every rep length and target pace is recalculated for you.
More vo₂max intervals sessions
- VO₂max intervals — Repeats of two to five minutes at around the pace you could hold flat out for ten minutes, with equal or slightly shorter recoveries.
- Pyramid intervals — Reps that climb in length to a peak and then come back down.
- 30/30 intervals — Thirty seconds hard, thirty seconds easy, repeated — accumulating time near VO₂max without the strain of long reps.
- Hill repeats — VO₂max-effort intervals run uphill, with the gradient supplying the resistance and capping the impact.