Research has shown that HIIT increases insulin sensitivity and also glucose metabolism in muscles in type 2 diabetes individuals. Glucose uptake had returned to a normal level in the thigh muscles after just 2 weeks of training. This was discovered in a research project which examined how high-intensity interval training impacted the health of diabetic and healthy individuals.[1]
HIIT, or high-intensity interval training, impacts metabolism rapidly. But, no major differences have been shown over a longer time period between the impact of HIIT and moderate intensity continuous training. HIIT’s main advantage is mainly that it requires much less time.
For the study, first healthy individuals in their 40’s and 50’s performed either HIIT or normal training of moderate intensity. Then another group of individuals having insulin resistance performed a similar training routine of 2 weeks. A number of the study participants had type 2 diabetes with others having elevated blood sugar levels, high enough to suggest prediabetes, but not enough to suggest type 2 diabetes.
Prior to the start of the training, the insulin sensitivity and glucose metabolism of the individuals who were insulin resistant were considerably reduced in comparison to the healthy individual group. After only 2 weeks of HIIT, which came to 6 sessions of training, the glucose metabolism in the thigh muscles had already reached the starting level of the healthy group individuals. The HIIT training sessions are short and extremely intensive followed by a recovery period. HIIT can be performed in maximum intensity training sessions of 30 seconds with a recovery period of one or two minutes.
There were improvements in insulin sensitivity and glucose metabolism following both the moderate intensity continuous training and the high-intensity training, so the study indicates that individuals can decide on the kind of training according to their own requirements. The group that performed the training of moderate intensity however achieved only half the improvement the HIIT group experienced within the 2-week period. So, this kind of training requires more time. HIIT can be a good alternative to standard training for those who have less time.
Endurance is also improved with HIIT. The study showed that there was an increase in endurance only in the HIIT type 2 diabetic group, but it has been shown in previous studies that when training carries on for more than 2 weeks, the increase in endurance is the same with the standard training of moderate intensity as it is with HIIT. The results of the research highlight the impact that exercise has on glucose metabolism particularly in diabetics and in individuals who have problems with disturbances in glucose metabolism. Earlier studies have shown that blood sugar is reduced with exercise as much as medication, so exercise is important for the treatment and prevention of diabetes.
With regards to endurance and glucose metabolism it doesn’t seem to make any difference if the exercise happens as moderate training over a longer time period or as HIIT over a shorter time period. Everyone can decide on the kind of training which is most suitable. The best results can generally had by making use of both training methods.
The researchers however recommend that a doctor should be consulted before a new exercise routine is started by individuals with type 2 diabetes. As an example, when there is a significant increase in the amount of exercise, it may be necessary to have medication checked.
