How To Run a Sub-20 Minute 5km In Just 5 Weeks - Lee Grantham

Aug 13, 2025

Intro

This is a quick summary of How To Run a Sub-20 Minute 5km In Just 5 Weeks from Lee Grantham. It’s a great watch — we’re breaking it down so you can try the workout today. Be sure to check out the full video for all the details.

Key Points

The 5K is a triangle of fitness: base = aerobic capacity, middle = speed‑endurance (lactate threshold), tip = V̇O₂max (raw speed). Most recreational runners over‑emphasize the base and neglect the middle and tip.
Lee’s five sessions are designed to attack speed‑endurance and V̇O₂max with short, fast repeats and a consistent 60‑second recovery.
Keep the rest interval at 60 seconds for every repeat; this trains your ability to recover quickly and maintain high quality effort.
Run each repeat at a pace faster than your 5K race pace – think of them as controlled accelerations or “super‑strides.”
Perform one of these sessions each week (e.g., Wednesday) while keeping the rest of your training focused on aerobic runs and a long run on the weekend.

Workout Example (Progression Over 5 Weeks)

Week	Reps	Distance per Rep	Total Volume	Recovery
1	20	100 m	2 km	60 s
2	20	150 m	3 km	60 s
3	20	200 m	4 km	60 s
4	20	250 m	5 km	60 s
5	20	300 m	6 km	60 s

How to run each repeat:

Accelerate from a jog to a sprint‑like effort for the full distance.
Focus on staying in control – imagine a fast stride but maintain good form.
After the repeat, jog or walk for 60 seconds to bring the heart rate down, then start the next repeat.

Practical Tips

If the reps feel too easy, increase the effort to make the pace noticeably faster than your 5K pace.
New to such short intervals? Expect some soreness the next day – it’s a sign you’re training the fast‑twitch fibers.
Keep the workout weekly; consistency is key for building V̇O₂max and speed‑endurance.
Pair these sessions with easy runs and a weekend long run to maintain aerobic capacity.

Closing Note

Give this progressive interval block a try this week and watch your speed improve. Feel free to adjust the paces to match your current fitness in the Pacing app – the structure stays the same, only the speed changes. Good luck, and enjoy the faster 5K you’re building! 🚀