Despite the massive rise in interval-based exercise programmes, I’m always surprised by how many blank faces I see when I talk about ‘HIIT’. HIIT stands for ‘high-intensity interval training’, and it’s essentially about adding heart rate boosting moves into a workout in order to burn more calories in less time. Shorter, more intense workouts are also good for muscle retention, as long periods of cardio can cause stress hormones to spike and eat away at muscle mass. But how do you know when you’ve entered the HIIT zone? Here are the five HIIT checks I do during every workout to make sure I’m getting maximum benefits.
1. You’re not thinking about anything else. If you’re really working to your maximum effort, you’ll be so consumed by the exercise that there’s no way your mind can wander. It’s a form of escapism exclusive to HIIT.
2. You only finish an exercise when you can’t physically complete another rep. HIIT isn’t about completing a pre-determined 10, 12 or 15 reps – it’s about exhausting a particular muscle group until you genuinely need a recovery.
3. Talking is near impossible. If you’re chatting about your weekend, you’re not in the HIIT zone. Save the catch-up for after your workout, because true HIIT training is sweaty, breathless business.
4. Every muscle is engaged. The best way to push your heart rate higher is to get your full body involved. If the cells in your upper and lower body are demanding oxygen at the same time, your heart has to work harder and faster to pump fresh blood in different directions.
5. You feel energised post-workout – if a little shaky. Unlike endurance work, which can break down muscle tissue and leave you feeling weary, HIIT burns primarily through your glycogen stores and fat reserves to reduce any symptoms of physical and psychological fatigue. My favourite time for a HIIT workout is over lunch, so I return to my desk feeling alert and invigorated.