Cardio and powerwalking

Fitness is the heart's and muscles' ability to use oxygen. It is built from time in motion at a pace you can hold – and topped with short, hard intervals.

How much

150–300 minutes of moderate activity a week (brisk powerwalk, cycling, easy jog) or 75–150 minutes vigorous is the WHO recommendation for health. More gives more up to a point, and even less than that helps compared with nothing. Spread it over several days if you can.

Talk pace – zone 2

Most cardio can be at a pace where you can speak in full sentences but not sing. That is usually called zone 2, roughly 60–70 percent of max heart rate (zone limits vary between models). Here the body uses a large share of fat for fuel and builds the aerobic base other work rests on. If it feels too easy, it is often right.

Powerwalk

6–7 km/h with active arms. Low injury risk, doable daily, burns in the region of 300–400 kcal an hour depending on body weight and pace. Hills and poles raise intensity without adding much load on the knees.

Intervals

Once a week, once the base is there: 4–8 bouts of 1–4 minutes at a pace where you cannot talk, with equal rest. The app tells you with voice and vibration so you never look at the phone. For most people one or two interval sessions a week is plenty.

Walk/run

From walking to running: short jog intervals growing week by week, as in the Run 5 km program. Jog at talk pace – many beginners run too fast.

The ten percent rule

A common rule of thumb: do not increase total time or distance by more than about ten percent a week. Evidence for the exact number is weak, but the principle is sound – tendons and joints adapt slower than the heart. Repeat a week if it felt heavy.

Heart rate

A heart-rate watch is nice but not necessary. The talk test goes a long way. Morning resting heart rate is a simple recovery gauge: if it is 5–10 beats above normal, that can be a sign to take an easy day.