Progression run

A run split into thirds, each faster than the last, finishing at or near threshold.

Also called: thirds run, negative-split run.

A progression run is the least intimidating way to get quality work done, which is exactly why it survives weeks when a track session would not. Starting genuinely easy is the hard part: most runners begin their first third at what should be their second-third pace and then have nowhere to go. Done right, it also rehearses the pacing discipline a marathon demands.

The session

Shown at a 4:00 marathon reference — 45 min total, about 7.6 km, including 30 min of quality work.

Session

  1. 15 min easy (6:43–7:24/km)
  2. 15 min float @ 5:41/km (M)
  3. 15 min @ 5:14/km (T)

Why this session works

Easy → marathon → threshold by thirds finishes the run at its fastest. Progression runs add quality with low perceived cost and teach patient pacing.

Source: Casado et al. 2022. 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 progression run?

A run split into thirds, each faster than the last, finishing at or near threshold. A progression run is the least intimidating way to get quality work done, which is exactly why it survives weeks when a track session would not.

How long is this session?

At a 4:00 marathon reference it comes to 45 min and about 7.6 km, of which 30 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 threshold and tempo sessions

  • Tempo run — One unbroken block at threshold pace — the effort you could hold for about an hour in a race.
  • Cruise intervals — Threshold pace broken into repeats with short jogs, so you accumulate far more time at the ceiling than one continuous block allows.
  • Threshold alternations — Alternating threshold and marathon pace with no standing rest, training the body to clear lactate while still running fast.
  • Tempo sandwich — A threshold block, a marathon-pace middle, then a second threshold block on tired legs.

See all 32 sessions in the library.