By now we probably know that exercise and physical activity are good for us. So why is it that in 2011/12, 70% of those living with diabetes did not meet the physical activity guidelines according to the Australian Institute of Health and Welfare (2015)? Probably due to a lot of factors! One of the most common barriers to being able to meet physical activity guidelines is time. This is not surprising given the hectic lives we all lead.
You may have heard that the benefits of exercise increase as physical activity levels rise. But, is there such a thing as ‘bang for your buck’ when it comes to exercise? Some may argue, yes! Current physical activity recommendations suggest we should try to include, if possible, some activities which are vigorous in nature due to its overall health benefits. These guidelines suggest 75-150 minutes of vigorous activity per week when compared to 150-300 minutes of moderate intensity activity per week. So, can even shorter, more intense bouts of exercise achieve the same benefits? Emerging evidence suggests that brief bouts of very high intensity, followed by short recovery periods can improve cardiovascular fitness for less time spent exercising.
Some of the confusion surrounding HIIT stems from the inconsistent definitions of the required length of interval and heart rate intensities to see benefits. A commonly used protocol involves 4 intervals at 85-95% maximum heart rate that last for 4 minutes with 3 minutes recovery between each interval. When you include a warm up and cool down, your total exercise time is still at about 40 minutes. Having said this, some argue that you can achieve improvements in fitness by using just one interval – 1×4 minute interval!
While more research is required in this area, the initial findings are very promising. But is HIIT suitable for everyone, and in particular, for those with diabetes? Early research suggests HIIT may improve the way our insulin works, improve our waists circumference and improve beta cell function (insulin producing cells). As with any new exercise regime, a chat with your GP or exercise physiologist is a great idea to establish which exercise is right for you. As the name suggests, high intensity interval training is done at high intensities, therefore some additional factors may need to be considered.
HIIT may not be suitable for those with certain heart conditions, complicated diabetes management or certain musculoskeletal problems. We know that for some people with diabetes, some musculoskeletal injuries occur more commonly. Sensible and slow progression of exercise is therefore important for someone with diabetes. For those requiring insulin or some types of oral medication, risk of hypoglycaemia (low blood glucose levels) may also need to be considered. It is a good idea to monitor your blood glucose levels more frequently when commencing new exercise regimes.
So, what is the best exercise for me? Usually, my answer to this question is, “the one which you can see yourself actually doing”. HIIT will certainly not be for everyone and more research is needed before HIIT becomes part of standard recommendations for people with diabetes. But, if it is something that you feel will suit you, discuss with an exercise physiologist or your treating GP.
Marian is a Diabetes Educator and an Accredited Exercise Physiologist at Diabetes WA.