Zone 2 is easy cardio at about 60 to 70 percent of your maximum heart rate, a pace you can still talk at. Two or three sessions of 30 to 45 minutes a week build your aerobic base, help recovery and improve fat burning.
A pace you can talk at
Zone 2 is the effort where you can still hold a conversation. It sits at roughly 60–70% of your max heart rate, the same zone the heart-rate calculator on this site marks as fat burn.
This kind of work builds the aerobic base everything else sits on: faster recovery between sets and sessions, and a body that gets better at burning fat, even at rest.
Slow down until it feels easy, then do it often.
How to find your zone 2
By heart rate. A rough maximum heart rate is 220 minus your age; the Tanaka formula, 208 − 0.7 × age, is a little more accurate for most adults. For a 35-year-old, Tanaka gives about 184 beats per minute, so zone 2 is roughly 110 to 129 beats per minute.
If you know your resting heart rate, the Karvonen method fits the zones to your own fitness. The heart-rate calculator on this page does both.
Any formula based on age is an estimate. Your real maximum can be ten or more beats higher or lower.
By feel. No watch? Use the talk test. In zone 2 you can speak in full sentences, but you would not want to sing. You could keep going for an hour. If you can only manage a few words at a time, you are above it.
Why easy is so effective
- Your heart gets stronger, pumping more blood with each beat.
- Your muscles build more mitochondria, the parts of the cell that use oxygen and fat for energy.
- Recovery improves, so your hard sessions get better.
- It is gentle on your joints and your nervous system, so you can do a lot of it without burning out.
Most people who start running go too fast every time. They feel tired, plateau, and quit. Slowing down is often what unlocks progress.
How to put it into practice
Aim for two or three sessions a week of 30–45 minutes: brisk walking, easy cycling or a relaxed row. Keep the hard days hard and the easy days genuinely easy; the gap between them is what drives progress.
A widely used guideline for endurance athletes is to keep about 80 percent of cardio easy and about 20 percent hard. For general health, the World Health Organization recommends at least 150 to 300 minutes of moderate activity a week, and zone 2 sessions count towards it.
Good ways to do zone 2
- A brisk walk, on flat ground or a slight incline
- An exercise bike or a gentle outdoor ride
- An easy jog, if you can keep your heart rate down
- A rowing machine at a steady, relaxed pace
- Swimming at an easy pace
In the hot months, do it early in the morning, after sunset, or indoors. Heat raises your heart rate, so slow down to stay in the zone.
Sources
- World Health Organization, physical activity fact sheet: who.int
The takeaway
Slow down, stay in a pace you can talk at, and do it two or three times a week. It feels too easy, and that is the point. If you train with a chest strap, the Shulah app can even time your rest between sets by your heart rate.