benefits of automated intervals

HIIT helps diabetics with their glucose

New research reveals that high-intensity interval training (HIIT) increases glucose metabolism in muscles as well as insulin sensitivity in type 2 diabetes. Already after a two-week training period, the glucose uptake in thigh muscles returned to a normal level.

The discovery was made in a research project led by Senior Research Fellow Kari Kalliokoski and Project Manager Jarna Hannukainen at the University of Turku, Finland. The project studied the health impacts of high-intensity interval training on healthy people and diabetics, and the results are encouraging.

“HIIT has a rapid impact on metabolism. However, no great differences have been demonstrated between the impact of HIIT and moderate intensity continuous training over a longer period of time. The main benefit of high-intensity interval training is mostly that it takes less time,” says Doctoral Candidate Tanja Sjöros.

First in the study, healthy men in their forties and fifties did either high-intensity interval training or traditional, moderate intensity training. Later, a group of people with insulin resistance carried out a similar two-week training routine. Some of them had type 2 diabetes and some prediabetes, i.e. their blood sugar levels were elevated but not yet high enough to indicate type 2 diabetes.

“Before the training started, the glucose metabolism and insulin sensitivity of the insulin resistant persons were significantly reduced compared to the group of healthy individuals. However, already after two weeks of high intensity training, which amounted to six training sessions, the glucose metabolism in the thigh muscles achieved the starting level of the healthy control group,” tells Sjöros.

In HIIT, the training sessions are highly intensive but short and followed by recovery period. For example, HIIT can be carried out in 30-second training sessions of maximum intensity and with a recovery sessions of a couple of minutes.

Glucose metabolism and insulin sensitivity improved after both the high-intensity training and the moderate intensity continuous training, so the study suggests that people can choose the type of training based on their own preferences.

“However, the group that did moderate intensity training achieved only half of the improvement experienced by the HIIT group during the two-week period. Therefore, this type of training requires a longer period of time. If you have only little time to spare, high-interval training could be a great alternative to traditional training that requires more time but is lower in intensity,” says Sjöros.

HIIT also improves endurance. In the study, the endurance of type 2 diabetics increased only in the HIIT group, but earlier studies have shown that, when the training routine continues for over two weeks, endurance increases with the traditional, moderate intensity training just as much as it does with high-interval training.

The research results published in the Scandinavian Journal of Medicine & Science in Sports highlight the beneficial effects of exercise on glucose metabolism especially in diabetics and in those who suffer from disturbances in the glucose metabolism. According to previous research, exercise lowers blood sugar as much as diabetes medication. Therefore, exercise is an essential part of treating and preventing diabetes.

“It’s particularly good news that when it comes to the glucose metabolism and endurance it does not seem to matter in whether the exercise takes place over a longer period of time as moderate training or over a short period as high-interval training. Everyone can choose the type of training that suits them best. In general, you can achieve the best results for you body by using both training methods,” encourages Sjöros.

However, the researchers advise that diabetics should consult their doctor before starting a new exercise routine. For example, if the amount of exercise increases significantly, it might be necessary to check the diabetes medication. Also other possible illnesses have to be kept in mind when planning a new exercise routine.


The best anti-aging exercise

HIIT it! We’re often told that exercise is the best medicine, and it now seems that regular high intensity interval training (HIIT), in particular, is great for reversing the declining ability of our cells to generate energy.

HIIT involves short bursts of very intense activity, interspersed with recovery periods of lower-intensity exercise. Sreekumaran Nair at the Mayo Clinic in Rochester, Minnesota, and his colleagues assigned groups of people aged between 18 and 30 and between 65 and 80 to three months of interval training, weight training or a combination of the two. Muscle biopsies were taken before and afterwards to measure the impact of these regimes on their cells.

Interval training boosted the ability of the mitochondria within cells to generate energy by 69 per cent in older volunteers, and by 49 per cent in the younger group. Mitochondrial activity declines with age, which may aggravate fatigue and reduce the size and ability of muscles to burn excess blood sugar – a risk factor for diabetes. But this decline was halted and even reversed in the older interval-training group. “After three months of interval training, everything converged towards what we saw in young people,” says Nair.
Interval trainers also saw surges in lung, heart and circulation health. The amount of oxygen they could inhale and consume at full tilt rose by 28 per cent in the younger group and by 17 per cent in the older group. There was no corresponding change among weight trainers, although combination training boosted oxygen consumption by 21 per cent among older exercisers.
Nair says the greatest benefit from weight training was the addition of new muscle mass, but it triggered none of the mitochondrial and respiratory benefits. The combination regime generally produced intermediate results.

Reduce stress and anxiety with high intensity exercise!

COLUMBIA, Mo. – Cardiovascular disease is the leading cause of death in the United States. The amount of stress and anxiety a person experiences is a major factor in cardiovascular disease. For the past three decades experts have vacillated in their recommendations concerning the amount and intensity of exercise required to alleviate stress and anxiety.

Recently, most experts have agreed that a moderate to low amount of regular exercise can ease personal tension and stress. However, a new study by researchers at the University of Missouri-Columbia shows that a relatively high-intensity exercise is superior in reducing stress and anxiety that may lead to heart disease. Moreover, the researchers found that high-intensity exercise especially benefits women.

“Conventional wisdom says that exercising for 30 minutes at a moderate exercise intensity is more effective in reducing anxiety than either a low or high intensity dose,” said Richard Cox, professor of educational and counseling psychology and leader of the study. “This conclusion, however, is deceptively simple because reductions in anxiety are not always observed immediately following a high intensity bout of exercise.”

In the study, female participants, ages 18 to 20 and 35 to 45, completed three experimental sessions. Each session started with a test to determine the anxiety level of the participant. Following the test, the women either did not exercise (control condition) or exercised at a moderate or high-intensity level for 33 minutes. After the session, Cox measured anxiety levels at 5, 30, 60 and 90 minutes post-exercise.

Although all three exercise conditions, including the control condition, showed a decline in anxiety over time, Cox found the high-intensity level experienced the sharpest decline. Cox said the intensity of exercise conditions did not differ in anxiety levels at baseline or immediately after exercise, but a difference favoring the high intensity level emerged at 30, 60 and 90 minutes post-exercise.

Results also showed that when the iron status of the women was taken into consideration, the beneficial effect of high-intensity exercise was greater for the older women.

“This is a relationship that needs to be further explored,” Cox said. “It appears to suggest that after controlling for iron status, the beneficial effects of exercise on anxiety may only apply to older women and not to younger women.”

Cox believes this study, which is scheduled for publication in the Research Quarterly for Exercise and Sport, will prove beneficial to medical practitioners in the fight against heart disease.