# Zone 2 training: a practical guide > Zone 2 training is easy, conversational aerobic exercise at roughly 60–70% of your heart-rate reserve — the intensity where you can still talk in full sentences. It builds your aerobic base, fat-burning and mitochondrial health at a low fatigue cost, and forms the foundation most endurance and general-fitness plans are built on. The bulk of your cardio should be here. Source: Lift Republic (https://liftrepublic.com/learn/zone-2-training) Category: Performance · Published: 2026-06-04 · Reviewed: 2026-06-04 Zone 2 is the unglamorous training that quietly builds the biggest engine. Most people skip it because it feels too easy — which is exactly why it works. ## What Zone 2 actually is Zone 2 is **easy, conversational aerobic exercise** — roughly **60–70% of your heart-rate reserve**. You should be able to hold a full conversation. It's the pace that builds your aerobic base, improves how well your muscles use fat for fuel, and increases mitochondrial density — all with a low fatigue cost, so you recover quickly and can do a lot of it. Calculate your zones from your age and resting heart rate below. [[calc:heart-rate-zones]] ## Why it matters - **Builds the base.** A bigger aerobic engine supports everything else — harder intervals, faster races, better recovery between gym sets. - **Low cost, high return.** Because it's easy, you can accumulate volume without digging a recovery hole. - **Health & longevity.** Aerobic fitness is one of the strongest markers of cardiovascular health (see [how to improve your VO₂ max](/learn/how-to-improve-vo2-max)). ## How to do it 1. **Pick a steady activity** — easy running, cycling, rowing, brisk incline walking. 2. **Hold the talk test** — full sentences, nasal breathing comfortable. If you're gasping, slow down. 3. **Go long, not hard** — 30–60 minutes is a typical session. 4. **Be patient** — early on you may need to slow right down (even walk) to stay in zone. The fitter you get, the faster your Zone 2 becomes. ## Where it fits Keep easy days easy and hard days hard — the polarised approach. Pair Zone 2 with the right amount of high intensity, and you build a durable, high-performing engine. Our [athletic-performance programme](/programmes/athletic-performance) sets your real zones from your [Garmin and Strava data](/learn/train-with-your-data) and balances easy and hard work for you. ## FAQ ### What is Zone 2 training? Zone 2 is easy aerobic exercise at roughly 60–70% of your heart-rate reserve — a pace you could sustain for a long time and still hold a conversation. It builds your aerobic base and is the foundation of most endurance training. ### How do I know if I'm in Zone 2? Use the talk test (you can speak in full sentences but not sing) or a heart-rate monitor set to your zones. Most people significantly overshoot Zone 2 — if in doubt, slow down. ### How much Zone 2 training should I do? For general fitness, two to four easy aerobic sessions a week is plenty. Endurance athletes often do the majority of their training in Zone 2, reserving a smaller portion for high intensity.