Short bursts of high-intensity exercise can be just as beneficial to blood vessels, including arteries that filter blood to the heart, as longer workouts of moderate intensity, new Canadian research says.
According to the findings, workouts consisting of a series of 30-second sprints three days a week improved the structure and function of arteries in study subjects just as much as moderate exercise at a longer intensity.
Improving artery function is one of the keys to maintaining cardiovascular health, the researchers said.
"As we age, the arteries become stiffer and tend to lose their ability to dilate, and these effects contribute to high blood pressure and cardiovascular disease," Maureen MacDonald, academic advisor to the study's lead researcher and an associate professor in McMaster University's kinesiology department, said in a statement.
Researchers from McMaster University in Hamilton, Ont., monitored study participants for six weeks. One group completed the interval training, while another group cycled at a moderate intensity for 40 to 60 minutes five days a week.
The research, led by McMaster kinesiology doctoral student Mark Rakobowchuk, was published in the American Journal of Physiology - Regulatory, Integrative and Comparative Physiology.
The findings support a trend among health-care professionals to recommend interval training to treat illnesses such as cardiovascular disease.
"Our research certainly provides evidence that this type of exercise training is as effective as traditional moderate intensity training," MacDonald said.
"We wouldn't be surprised to see more rehabilitation programs adopt this method of training since it is often better tolerated in diseased populations."
The findings also suggest that otherwise healthy people who can't make time for longer workouts can reap health benefits from short-term, high-intensity exercise.
Abstract:
Sprint interval and traditional endurance training induce similar improvements in peripheral arterial stiffness and flow mediated dilation in healthy humans
Mark Rakobowchuk, Sophie Tanguay, Kirsten A. Burgomaster, Krista Roylene Howarth, Martin J. Gibala, and Maureen J MacDonald
Low-volume sprint interval training (SIT), or repeated sessions of brief, intense intermittent exercise, elicits metabolic adaptations that resemble traditional high-volume endurance training (ET). The effects of these different forms of exercise training on vascular structure and function remain largely unexplored. To test the hypothesis that SIT and ET would similarly improve peripheral artery distensibility and endothelial function and central artery distensibility, we recruited 20 healthy untrained subjects (age: 23.3 � 2.8) and had them perform 6 wk of SIT or ET (n = 5 men and 5 women per group). The SIT group completed 4-6 x 30s "all-out" Wingate Tests separated by 4.5 min of recovery, 3 d/wk. The ET group completed 40-60 min of cycling at 65% of their VO2peak, 5 d/wk. Popliteal endothelial function, both relative and normalized to shear stimulus, was improved after training in both groups (main effect for time, P<0.05). Carotid artery distensibility was not statistically altered by training (p=0.29) in either group, however popliteal artery distensibility was improved in both groups to the same degree (main effect, P<0.05). We conclude that SIT is a time-efficient strategy to elicit improvements in peripheral vascular structure and function that are comparable to ET. However, alterations in central artery distensibility may require a longer training stimuli and/or greater initial vascular stiffness than observed in this group of healthy subjects.
