How to run THRESHOLD correctly (tip SLOW DOWN) - Stephen Scullion - Olympic marathoner

Aug 13, 2025

Intro

This is a quick summary of How to run THRESHOLD correctly (tip SLOW DOWN) from Stephen Scullion - Olympic marathoner. It’s a great watch — we’re breaking it down so you can try the workout today. Be sure to watch the full video for all the details.

Key Points

Pre‑run activation: 5 quick exercises (calf walks, heel walks, walking lunges, glute bridges, upper‑body swirl) plus diaphragmatic breathing to get muscles and lungs ready, reducing the first 3‑4 minutes of “hard” feeling.
Threshold concept: Keep lactate around 3‑4 mmol/L. Going faster pushes lactate above 4 mmol/L and leads to heavy legs and quick fatigue.
Progressive pacing: In a 45‑50 minute run, start easy (even walking), then gradually speed up so the last 4‑5 minutes are the fastest. Use heart‑rate, speed, and perceived effort rather than just watch speed.
Lactate awareness: If you can keep effort at a level where you could still hold a conversation, you’re likely in the right zone. Below 2 mmol/L is easy; 3‑4 mmol/L is solid threshold work.

Workout Example

Warm‑up: 2 miles (≈3.2 km) at easy pace, HR ~115‑120 bpm.
Threshold intervals – 8×1 km repeats (or 1 km repeats) on a treadmill or track:
- Repeat 1‑2: easy (just to get moving).
- Repeat 3 & 6: slightly harder – aim for a pace that pushes your lactate toward ~3 mmol/L (roughly 12 mph for Stephen).
- Other repeats: maintain the same pace as 3 & 6, keeping effort steady.
- Recovery: 30 seconds easy jog between repeats.
Cool‑down: 5‑10 min easy jog, check that lactate (or perceived effort) drops back toward 1‑2 mmol/L.

Tip of the day: Do a 45‑50 minute run where you start slow and finish the last 4‑5 minutes at your fastest sustainable effort. Use your watch to monitor HR and speed, but trust how your breathing and leg feel.

Closing Note

Give this threshold workout a try today, and feel free to tweak the paces to match your own fitness using the Pacing app. You’ve got this – keep it steady, stay in control, and enjoy the progress!