Lack of time is often the main reason people don’t exercise regularly. But a type of interval workout recently popularised by actress Jessica Biel could be the solution – with research showing it can improve fitness faster than traditional, steady-pace workouts, such as jogging or cycling.
The Norwegian 4x4 workout has traditionally been used by athletes. It’s a form of high-intensity interval training (Hiit) that involves four-minute sets of very intense cardio exercise, followed by three minutes of very light exercise. A typical training session includes a five-minute warm-up, four high-intensity intervals and a five-minute cool-down.
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