What is polarised training (and why we should do it) - This Messy Happy

Aug 13, 2025

Intro

This is a quick summary of What is polarised training (and why we should do it) from This Messy Happy. It’s a great watch — we’re breaking it down so you can try the approach today. Be sure to check out the full video for all the details.

Key Points

Polarised training splits your weeks into ~80% easy (Zone 2) work and ~20% hard (high‑intensity) work; the middle “junk miles” zone adds little benefit.
Easy Zone (Zone 2): ~6/10 effort, about 89% of lactate‑threshold heart rate, you can hold a relaxed conversation for the entire run. Build a strong aerobic base.
Hard Zone: 9‑10/10 effort, short intervals where talking is impossible. Improves VO₂ max, lactate threshold, and overall performance.
Junk Miles (Zone 3, high‑7 to low‑8/10) are neither easy enough for aerobic gains nor hard enough for VO₂ max gains; they’re generally wasted.

Workout Example

Easy days (80% of weekly mileage): Run at a comfortable conversational pace (Zone 2) for the majority of your weekly mileage. Example: 5 × 10 km runs at easy pace, plus a long run (15‑20 km) at the same easy intensity.
Hard days (20% of weekly mileage): Include interval or high‑intensity sessions. Example: 5 × 3 min intervals at 90‑95% max heart rate (or 9‑10/10 effort) with 2‑3 min easy jog recovery, done 1‑2 times per week.

Closing Note Give the 80/20 polarised approach a try this week, adjusting the paces to suit your own fitness in the Pacing app. You’ll feel stronger, faster, and more confident on every run—go for it!