---
title: "Zone 2 is essential. It’s also not enough."
date: 2026-01-25
categories: ["Training"]
url: https://www.semiprocycling.com/digest/zone-2-is-essential-its-also-not-enough
author: Damian Ruse (SEMIPRO Cycling)
---
# Zone 2 is essential. It’s also not enough.

![](https://www.semiprocycling.com/digest/images/a18d0cb59ff362494efd4524.webp)

Zone 2 is everywhere. It’s sold as the “mitochondria gear” and the safest route to longevity.

A 2025 narrative review in *Sports Medicine* takes a hard look at that story, specifically for the general population. The authors argue the current evidence does not support Zone 2 as the *best* intensity for improving mitochondrial or fat-oxidation capacity. They also point out that higher intensities often drive bigger cardiometabolic benefits, especially when weekly training volume is low.

That detail matters. This is not a pro cyclist problem. Most adults are not training 12–20 hours a week. They’re doing 2–5, if that. In that context, an “all Zone 2” plan can be too gentle to meaningfully lift cardiorespiratory fitness for many people.

So what does this mean for Zone 2?

Zone 2 still earns its place. It’s repeatable. It builds routine. It lets you stack minutes without blowing up your week. If your goal is healthspan, consistency is the point.

The shift is the claim. Zone 2 is not a magic key. If you want a higher ceiling (fitter heart and lungs, more robust fitness), you likely need a small dose of work above Zone 2 as well.

A simple framework:

1. Keep most sessions easy enough to speak in full sentences.
2. Add 1–2 short “hard” blocks each week that make speech choppy.
3. Keep easy truly easy so the hard work actually lands.

Keep Zone 2. Drop the worship. Train with intent.

Reference:

**Storoschuk KL, Moran-MacDonald A, Gibala MJ, Gurd BJ.** Much Ado About Zone 2: A Narrative Review Assessing the Efficacy of Zone 2 Training for Improving Mitochondrial Capacity and Cardiorespiratory Fitness in the General Population. *Sports Medicine*. 2025;55(7):1611–1624. doi:10.1007/s[40279-025-02261](tel:40279-025-02261)-y.

## On my mind: Why the First Few Rides Always Feel Worse

I got a new road bike this week.

And honestly, I don’t even enjoy buying bikes. I just want to ride them.

The annoying bit is always the same. The first few rides feel a bit off. Position isn’t quite right. Things you never thought about suddenly stand out. You’re fiddling, adjusting, wondering why it doesn’t feel as good as the old one yet.

Nothing’s wrong. It just hasn’t settled.

It reminded me how often that happens with training too. You change something for the better, but the first reaction is discomfort. More awareness. A bit of doubt. It feels worse before it feels better.

Most people read that as a sign they should stop.

Usually it’s just the awkward middle. The part you have to ride through before things click.

Same with the bike. You don’t judge it on day one. You give it time to make sense.

Damian