In what could be good news for those too time-pressed for much exercise, new research shows significant benefits can be gained from more intense workouts that take less time.
A study published in the American Journal of Human Biology compared the effects of two different approaches to exercise on British teenagers. The youths were separated into three groups, two of which took part in exercise sessions three times a week for seven weeks.
One group would run steadily for 20 minutes in each session. Another would take part in four to six sprints of 20 metres, with rest times of 20 to 30 seconds between. A control group was not subject to any manipulation of their fitness habits.
At the end of the program, each group involved in the training saw significant improvements in measurements of cardiovascular health. But one cohort put in a total of seven hours to achieve such results, and the other spent about one hour in total over those seven weeks — averaging three minutes a session.
"Overall, results of the study indicated that the two exercise programs had distinct cardio-protective effects on adolescent youth," says the study, led by Duncan Buchan from the University of the West of Scotland. "However, it is important to note that the HIT (high-intensity) group experienced improvements despite a substantially lower exercise time commitment."
Robert Malina, a retired professor of health education at the University of Texas who assisted with the study, said it shows health benefits of exercise can be optimized by increasing the intensity of activity. He said it also shows that measures to improve and maintain fitness need not be overly time-consuming.
This is a particularly important message to get across to youth, he said, noting that adolescence is an important time of life for forming habits and developing physical capabilities that can last into adulthood.
"The important thing when you work with youngsters is: How do you keep them interested in the activity?" Malina said. "The activity should be enjoyable and give them a chance to do different things. . . . Try to give them a good workout so they're not worried about spending an hour in a gym."
However, Malina said people — particularly adults — need to be careful about taking part in high-intensity exercises when they are not physically fit to do so. Otherwise they risk heart attack.
Martin Gibala, a kinesiology professor at McMaster University in Hamilton, Ont. said he's been involved with past research, which involved adults, that showed health benefits from intense exercise that takes less of one's time than endurance-related workouts.
He warned that people should consult a physician and take a gradual approach to this kind of "interval" training. However, he added that it is an acceptable type of exercise for all kinds of people; not just elite-level athletes.
"We're not advocating that just anyone jump up and do this kind of training, but more people than you think can benefit from an interval-based approach to fitness." Gibala said.
While both groups of youths in the study saw benefits from the exercise programs, there were some differences in the results.
The high-intensity workout group saw improvements in terms of blood pressure, body mass index (BMI) and aerobic fitness. Those in the less intense, more time-consuming exercise saw even more improvement in aerobic fitness, a reduction in body fat percentage as well as BMI, and healthier insulin levels.
Asked which combination of results were better, Malina said: "That's a tough call because I don't think the programs were sufficiently long enough, and we did not do a followup study."
source: vancouversun
No comments:
Post a Comment