In HIIT you don't train at a steady pace but in intervals. A typical session consists of effort phases of 20 to 60 seconds at around 80 to 95 percent of maximum heart rate, followed by active or passive rests of 10 to 60 seconds. Popular exercises include burpees, mountain climbers, jumping jacks, squats or sprints – often with no equipment, using just body weight. A well-known format is Tabata: 20 seconds all-out, 10 seconds rest, repeated eight times, meaning four minutes per exercise.
The physiological stimulus comes from switching between maximum effort and recovery. The body burns a lot of energy not only during the workout but, thanks to the so-called afterburn effect (EPOC), for hours afterwards. Studies show that HIIT often improves endurance and insulin sensitivity as effectively as much longer steady-state cardio – with less time invested.
A full HIIT session, including warm-up and cool-down, usually lasts 20 to 40 minutes. This brevity is exactly what makes it attractive for busy people. Two to three sessions per week with recovery days in between are recommended, since the high intensity places heavy demands on the body.
HIIT suits people who already have a base level of fitness. Beginners and those with cardiovascular conditions, high blood pressure or joint problems should seek medical advice first and start at reduced intensity. A proper warm-up, clean technique despite fatigue and sufficient recovery are essential – otherwise the injury risk rises.
In Swiss gyms HIIT is usually offered as a group class. A drop-in costs roughly CHF 25 to 40 depending on the region, and an unlimited monthly membership around CHF 120 to 250 (no guarantee). Pure bodyweight HIIT workouts can also be done at home for free.