High Intensity Training, or HIT, seems to be the latest trend in fitness training, promising big results in a fraction of the time of conventional training routines. So what is it all about, does it work and is it for you? Here we’re going to look at the science behind the claims.
What is HIT?
HIT was actually first described in a 1996 study published in the journal Medicine and Science in Sports and Exercise. Dr Izumi Tabata asked healthy and fit cyclists to perform 20 seconds of intense exercise (in this case cycling) followed by 10 seconds rest; then 20 seconds intense cycling and 10 seconds test.
A total of 6-8 repetitions gave about 4 minutes workout time. This was repeated 5 days a week for 6 weeks.
A control group were asked to do moderately intense training for an hour 5 times a week (giving a total 1800 minutes against the study group’s 120 minutes).
The results?
The results were staggering. In the study group it was found that their measured aerobic and anaerobic endurance improved markedly.
Aerobic exercise means ‘with oxygen’ and is what we achieve when we do cardio workouts at a moderate intensity. This type of exercise helps reduce the risk of diabetes and heart disease for example and is useful for weight loss.
Anaerobic exercise relies on the muscles’ own energy stores rather than oxygen from breathing. It is short-lasting and intense. The advantage to anaerobic exercise is that it:
- helps you develop stronger muscles and
- gives greater endurance (due to better management of waste lactic acid) and
- improves the amount of oxygen you can consume when you exercise – more oxygen = better health. This is referred to as ‘VO2Max’.
Further published studies in 2007, 2008 and 2009 reached similar conclusions.
How do you get into HIT?
Like any other exercise program, talk to your doctor before starting HIT if you have any concerns as HIT is not for everyone.
Because HIT needs you to push yourself really hard, it is designed for fit and active people who are already exercising regularly at an intermediate to advanced level. If you’re new to exercise we’ll look at how to get started with HIT too, but you would be well advised to talk to a fitness professional and work with him/her until you’re confident.
- Don’t be tempted to swap all your workouts for HIT. Use it only in place of 1 or 2 of your usual cardio routines because your muscles need to recover – it will make you ache at the start!
- It can be done with nearly any type of cardio exercise – running, cycling, skipping (jump rope) etc.
- Start with your chosen exercise at a gentle warm up pace for 8-10 minutes ; towards the end of that time gradually increase the pace.
- Have a timer or watch with a second hand that will tell you when to sprint and when to rest. Now do 20 seconds high intensity, full throttle work. Now stop or jog/peddle slowly for 10 seconds. Repeat these intervals a further 7 or 8 times, going full throttle each time.
- Cool down for 5-10 minutes and do some stretches.
If you’re a beginner to exercise, use this HIT regime no more than once a week, with a fitness professional and work at a lower intensity (50% of your max heart rate – see below). You’ll be able to increase the intensity as your fitness levels improve.
Should I use a heart rate monitor?
No special kit is needed for HIT (other than the bike/jump rope/and best trainers etc you’re already using). However, if you want to monitor your heart rate and track your improvement, a heart rate monitor will be useful.
Several reviewers have looked at individual monitors and there’s a link here to the sports and fitness watches category on this site.
For this High Interval Training you need to be working at about 75% of your maximum heart rate. A heart rate monitor with the correct settings will show you this and help to keep you there.
If you don’t have a heart rate monitor then you can work out 75% of your max heart rate and will need to take your own pulse in the wrist (the radial pulse) to measure it.
- Work out your max heart rate by taking your age from 220. For me this would be: 220 – 43 = 177 (177 is my max heart rate).
- To calculate 75% of your max heart rate: 177 x 0.75 = 133 beats per minute.
- To calculate 50% of your max heart rate, for a beginner: 177 x 0.5 = 89
Alternatively you can use the rate of perceived exertion table as follows:
- Rest
- Very light exertion
- Light exertion
- Fairly light
- Somewhat hard
- -
- Heavy exertion
- Extremely hard
- Very hard
- Maximal exertion
Aim for 5-7 intensity with your HIT workouts.
Can I use HIT for weight loss?
High Intensity Training is designed primarily to help regular exercisers and those who are already pretty fit step up their game, as part of a regular fitness regimen. HIT will give your metabolism a boost but calorie control and regular cardio exercise will better help with weight loss. So the answer to the question is ‘yes, but only with other measures as well.’
Stretches and toning exercises like Pilates and yoga will also help the muscles stay long and lean.
Does HIT really work?
The studies done in the 1990s and between 2007 and 2009 were small but produced similar results. In 2012 in the UK a doctor put himself through this regimen and recorded it for TV. He also summarised his experience in an article for the BBC.
His results also looked at his blood glucose levels (which we haven’t discussed here) and he was only using HIT as exercise, where it is recommended that HIT supplements your fitness program.
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