TOO BUSY FOR EXERCISE??
“I don’t have time to exercise” is one of the biggest barriers to exercise that we hear in today’s fast paced world.
What if I told you that there is a way that you can get the benefits of exercise in a fraction of the time?
Introducing… High intensity interval training.
High intensity exercise?? Ugh! But don’t let the name put you off - because what the name fails to mention is the ‘rest’ part of the training session. Perhaps a better name would be ‘High intensity interval training with heaps of rest time.’ Sound a bit better?
High intensity interval training (HIIT) is a form of aerobic exercise training that alternates between periods of high intensity exercise efforts, and recovery periods, of varying duration. It has taken the fitness world by storm for two reasons - it is effective, and it is time efficient.
The nature of having ‘rest’ intervals dispersed throughout the workout means that you are able to exercise at a much higher intensity during the ‘high’ intervals than you would during a continuous, steady state exercise bout.
Is HIIT training better than continuous intensity exercise?
If you guessed yes then you’ve ‘HIIT’ the nail on the head! The ability to exercise at a higher intensity has been proven to elicit adaptations that are on par with, and often even superior to those of continuous, moderate intensity exercise!
Here are some (pretty compelling!) reasons to consider HIIT training for your next exercise session…
1. It’s better for your heart health.
Not only is HIIT the fastest and most effective way of improving your fitness, it has also been proven to have better ‘cardio-protective’ effects than moderate intensity exercise - by increasing the heart’s ‘strength’ (it is a muscle after all), decreasing blood pressure, and therefore reducing your risk of events such as heart attacks and strokes. Intensity matters!
2. It can help improve your blood profile.
HIIT has been proven to be equally as effective as moderate intensity exercise in increasing insulin sensitivity (i.e. the ability for your body to process the levels of sugar in your blood), preventing problems with blood glucose control such as diabetes. It can also help to improve cholesterol control and increase the number of ‘good’ HDL cholesterol, further reducing your risk of heart disease!
3. It can increase your metabolism and aid in weight loss.
It does this by a process known as Excess Post-Exercise Oxygen Consumption (EPOC). When we exercise at higher intensities, our metabolic system switches from aerobic metabolism (utilising the available oxygen to create ‘usable’ energy) to anaerobic metabolism (creating energy in the absence of oxygen). I think of anaerobic metabolism as if you are ‘borrowing oxygen’, which must eventually be restored when the muscles are given a chance to recover. This means that the oxygen consumption is higher for longer, and you keep burning calories for longer after the workout is finished!
4. It’s great for stress relief.
You know how sometimes you just feel like you need to let out a bit of pent up frustration from your day? Need I say more? HIIT is also often reported to be more enjoyable than continuous intensity exercise, meaning that those feel good endorphins that follow are optimised.
5. Last but not least… Did I mention that it is time efficient?!
Music to the ears of anyone who struggles with time-poverty! Less than 30 minutes per session (of which less than 10 minutes is actually at high intensity) completed 3 times per week has been shown to be effective at improving overall health and fitness in only a few weeks!
So how does one go about starting interval training?
There are numerous variables (intensity, duration of work, duration of rest) that can be modified when designing a HIIT session, and you may want to work with an exercise professional to create a HIIT program that will work best for you. Here are a few tips to get you started…
Mode: HIIT is typically utilised in the context of aerobic exercise modes, such as running, biking, swimming, rowing etc. It can also include other activities that involve fast, repetitive movements (e.g. high knees, star jumps), provided that they provide enough of a cardiovascular stimulus to get the heart rate up!
Intensity: The high intensity component should be at an intensity that increases your heart rate to 80% - 95% of your maximal heart rate. To calculate this range, you can use the equation of ‘220 - Your Age’ to estimate your maximal heart rate (note - this is only an estimate and your personal maximal heart rate may vary slightly). Then multiply this number by 0.8, and 0.95 to determine your 80-95% range. The low intensity interval should be at an intensity that you feel you are able to recover at (trust me, you’ll be needing it if you’re doing the high intensity component right!).
Time: The time intervals can vary from anywhere between 10 seconds to several minutes! Think of it in terms of the work : rest ratio. Obviously the higher ratio (more work, less rest) at a given intensity, the harder the workout will be. You could start at a 1:2 ratio (e.g. 30 - 60 seconds at high intensity, and 60 - 120 seconds recovery), then progress to 1:1 (60 seconds alternating at each). Aim to work towards a total duration of 20 minutes or more (including a warm up and cool down of 3-5 minutes either side), repeated 2-3x per week.
With so many benefits available for such a low time cost, you still reckon you’re too busy for exercise??
Please note: If you are not currently completing regular aerobic exercise, we recommend having a lead in period of 2-4 weeks of moderate intensity aerobic exercise to build up a foundational fitness before beginning a HIIIT program. Please consult your health care provider first if you have any health considerations that may be influenced by intense exercise.
This blog was originally written for Specialised Health, an Australian & NZ based exercise physiology provider. To check it out, as well as heaps of other awesome content, head over to https://specialisedhealth.nz
References:
- High-Intensity Interval Training to Maximize Cardiac Benefits of Exercise Training? (Wisløff et al, 2009)
- The Potential for High-Intensity Interval Training to Reduce Cardiometabolic Disease Risk (Kessler et al, 2012)
- Effects of high-intensity aerobic interval training vs. moderate exercise on hemodynamic, metabolic and neuro-humoral abnormalities of young normotensive women at high familial risk for hypertension (Ciolac et al, 2010)
- Is high-intensity interval training a time-efficient exercise strategy to improve health and fitness? (Gillen and Gibala, 2014).