“Zone 2” refers to steady, moderate aerobic exercise — hard enough to raise your heart rate, easy enough to hold a conversation. It’s become popular among endurance athletes and longevity enthusiasts alike.
What Zone 2 feels like
The simplest test is the talk test: you can speak in full sentences but wouldn’t want to sing. Brisk walking, easy cycling, an easy jog or swimming at a relaxed pace usually fit.
By heart rate, it’s often described as roughly 60–70% of your maximum heart rate. Formulas for maximum heart rate (such as 220 minus age) are rough estimates, so effort and the talk test are often more reliable.
Why it’s popular
At this intensity, the body relies heavily on fat for fuel and builds aerobic capacity — more mitochondria, better blood vessel function, and a more efficient heart. Because it’s not exhausting, you can do more of it, more often, with less injury risk.
What the evidence supports
Moderate-intensity aerobic exercise is strongly linked with lower risk of heart disease, type 2 diabetes, depression and early death. That’s the core of the public health guidelines: 150 minutes a week of moderate activity.
Some of the more specific claims about Zone 2 — that it’s uniquely superior for longevity or metabolism — go beyond the evidence. Higher-intensity work also has benefits, and a mix of intensities seems sensible.
How to use it
- Make most of your cardio comfortable and steady — for example, 30–45 minutes, three or four times a week.
- Add one shorter, harder session a week if you enjoy it and your health allows.
- Combine with strength training twice a week.
For many women in midlife, Zone 2’s real advantage is practical: it’s sustainable, joint-friendly, and easy to fit into life — a brisk walk counts.