It’s generally recommended that people with pre-diabetes or type 2 diabetes get at least 30 minutes exercise, on most days of the week. The type of exercise prescribed tends to be a combination of aerobic activities that make us puff and the ‘resistance’ training that boosts body strength. What hasn’t been clear is the ideal intensity for working out.

Some experts have suggested that high intensity exercise is better for increasing insulin sensitivity and improving blood glucose levels. Others have said that it’s total energy expenditure that counts - meaning that a longer, low intensity session should be as beneficial as a short, high intensity session.

Then there’s the argument that best type of exercise is one that people actually do. There’s unlikely to be any benefit if high-intensity sessions are too difficult or daunting to persevere with. Long-term improvements in blood glucose control only occur if people catch the exercise bug and keep it.

High versus low

To test whether a single bout of low intensity exercise of longer duration was as effective in improving blood glucose control as a shorter, more intense session, researchers asked people with type 2 diabetes to perform low or high intensity cycling workouts matched for total energy expenditure.
They found that a single low intensity session lowered average glucose levels and reduced the prevalence of high blood glucose by around 50 per cent in the 24-hour period after exercise. A single high intensity workout was no more effective.
This means a lower intensity workout that takes a little longer will be just as effective as a short, express session. This is good news because it means a brisk walk will work its magic on blood sugar just as well as a quick jog.
The ‘talking threshold’ is a good way to judge if you’re working hard enough to maximise the health benefits from physical activity. If you can talk normally during activity you need to work a little harder. If you’re too puffed to speak, you should ease back on the intensity.


References:
Praet SF, van Loon LJ (2009) Exercise therapy in type 2 diabetes. Acta Diabetolgica 46: 263-278.

Manders RJ, Van Dijk JW, van Loon LJ (2009) Low-intensity exercise reduces the prevalence of hyperglycemia in type 2 diabetes. Medicine and Science in Sports and Exercise 42: 219-225. Diabetes Care

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