Sub-3 Marathon Speed Session
Workout - Sub-3 Marathon Speed Session
- 15min @ 6'30''/km
- 6 lots of:
- 1.0km @ 3'45''/km
- 1min rest
- 12min @ 7'00''/km
to import the workout after you install it.
Intro
Lee Grantham’s video on The Fastest Way to Run a Sub-3 Hour Marathon (Start Here) offers a solid breakdown of what you need to know. We’ve pulled the main takeaways so you can implement one of these sessions immediately. (Watch the full video for deeper context on each phase.)
Key Points
- Build your speed foundation: Breaking three hours demands that you first improve as a 5 km and 10 km runner — shoot for around 3:45 min/km (≈6 min/mi) pace.
- Concrete targets: Hitting 5 km in ~18:45 and 10 km in ~37‑38 min gives you the capability to sustain ~4:15 min/km for 42 kilometers.
- Steady progression: Begin from your current fitness level, maintain consistency week to week, and pair your hard workouts with recovery runs and a structured taper.
- Track your heart rate: Monitor peak and recovery HR during intense intervals to verify you’re working at a sustainable level.
- Know your limits: Overtraining stalls progress. If you’re still fatigued on long-run day, scale back the previous interval session.
Workout Example
Session 1 – 1 km repeats
- 10‑15 min of easy running to warm up.
- 6 × 1 km at 3:45 min/km, with 60 s jogging recovery between each.
- 10 min cool-down at easy pace.
Session 2 – 400 m repeats
- 10‑15 min warm-up.
- 15 × 400 m at 3:30 min/km (roughly 15 s quicker than marathon pace) with 60 s between reps.
- 10 min cool-down.
Session 3 – 1600 m repeats
- 10‑15 min warm-up.
- 3 × 1600 m at 3:45 min/km (slow it slightly if needed) separated by 60 s recovery.
- 10 min cool-down.
Progression Run (6 km)
- 2 km @ 4:10 min/km → 2 km @ 4:00 min/km → 2 km @ 3:50 min/km (optionally finish the final 2 km @ 3:45 min/km).
All paces can be customized to your current level — the Pacing app lets you plug in your own numbers.
Closing Note
Run through these workouts, observe your heart rate and perceived effort, and dial in the paces over time. As you log consistent sessions, you shift from being a pure 5 K runner into someone capable of a sub-3 hour marathon. Load up the Pacing app to adjust intervals to your own fitness, then watch the results compound—you can do this.