High intensity interval training (HIIT as some people call it) has become a bit of a buzz word over the last years. High intensity interval training involves workouts with short intervals (15 seconds to 4 minutes) interspersed with similar short length rest periods. During the work intervals you can use standard cardio machines (run, spin, row) or do other circuit based exercises (often bodyweight based such as squats, lunges etc). In HIIT the sessions are a lot harder and shorter than your traditional cardio sessions (e.g. 30-40 minutes of jogging). A typical HIIT session may look like this:
- 45 seconds of running
- 15 seconds rest
- Repeat 1 and 2, 6 times
- Take 3 minutes of rest
- Repeat steps 1-3, three times, giving a total session time of 24 minutes
You could also consider using a heart rate monitor to assess your exercise intensity during a HIIT session.
Pros of HIIT
- It’s time efficient – you can get an effective training session in less than 20 minutes.
- Reviews have shown HIIT more effective than medium intensity training at improving vascular function, improving insulin sensitivity, and improving cardiovascular disease risk factors (Ramos et al 2015).
- Other reviews have demonstrated likely greater improvements in aerobic fitness with HIIT vs endurance training (Weston et al 2014).
- It can add some variety to your training.
Cons of HIIT
- It’s a highly demanding form of training and can put strain on the body if you don’t have a reasonable training base behind you.
- If a progressive training program is not followed overuse of HIIT can lead to over training and increased injury risk. Read about tips on how to structure your training year.
A word of warning to finish with though – HIIT is demanding on the body and so it’s important you don’t go too hard too soon (as a guide don’t do more than 2 HIIT sessions per week). Also, if you’re over 55, have any niggling injuries or have history of cardiovascular disease have a chat to your doctor first.
By Dr Laurence Houghton (PhD Sports Science)