Latest Science on Zone 2 Training: Have We Been Doing It All Wrong?

New research flips the script on endurance training! You won’t believe what they found about low-intensity training!

The Big News: Zone 2 Is More Important Than Ever

Forget what you thought you knew about Zone 2 training! A groundbreaking new study published in the International Journal of Sports Physiology and Performance has revealed that elite endurance athletes—especially runners—spend far more time in Zone 2 (of a 5-zone model) than many people expect.

And here’s the kicker: they’re NOT talking about your “moderate” threshold training. They’re talking about truly easy, aerobic miles—below the first lactate threshold (LT1).

🚨 Yes, the Zone 2 training you thought you were doing? You might be overcooking it! 🚨

Key Takeaways from the Study

This study looked at elite middle- and long-distance runners and analyzed their training intensity distribution (TID) over an entire season. Here’s what they found:

✅ Most training time (~80%) is spent in Zone 1 and Zone 2 (of a 5-zone model).
✅ True “Zone 2” (below LT1) was a major focus—NOT the “sweet spot” training some cyclists associate with Zone 2.
✅ As competition season approached, training shifted slightly toward high-intensity work—but not as much as you’d think.

💡 The takeaway? More truly easy training leads to greater long-term endurance gains.

What Does This Mean for Cyclists?

Cyclists often think of Zone 2 as that moderate, tempo-ish, fat-burning intensity—but in this study’s 5-zone model, Zone 2 is purely aerobic, a true endurance-building effort.

🚴‍♂️ The mistake? Many cyclists go too hard in their “Zone 2” training, creeping into what’s actually Zone 3 or even 4.

💥 Instead of pushing that 75-85% FTP range, you might need to slow down to truly reap the benefits of endurance training.

How to Apply This to Your Cycling Training

1️⃣ Use a 5-Zone Model – Instead of thinking in just 3 zones (Easy, Tempo, Hard), break it down into 5 proper zones, where Zone 2 is truly below LT1.

2️⃣ Train Slower Than You Think – If you’re breathing hard, you’re probably not in the real Zone 2. Keep it conversational.

3️⃣ Don’t Neglect High-Intensity Work – The study found small but critical doses of high-intensity training near competition time, but not at the expense of easy mileage.