As the amount of time we can afford to dedicate to daily exercise dwindles, we wonder whether the 30-minute workout is a hard and fast recommendation. Is there a shorter solution that is just as effective? A new study at McMaster University in Hamilton, Ontario, Canada, has shown that short intervals of exercise improve the function of the heart and blood vessels. However, people seeking optimal fitness and weight loss will benefit more from traditional workouts.[i] There are several things to consider before committing to a quick workout routine.
Traditional Exercise Recommendations
Several health-related institutions, such as the American Heart Association, have traditionally recommended half-hour workouts for the maximum health benefit. The workouts need not be strenuous, but they must be continual to build endurance and maintain an elevated heart rate for at least 30 minutes. Most doctors agree that a half-hour, brisk walk or light run is an effective way to stay in good shape.
How Interval Training Works
Interval training condenses the half-hour fitness routine into 15 or 20 minutes. Instead of warming up and then exercising for half an hour, you warm up and then exercise in quick bursts of intensity. Most interval workouts involve a full minute of all-out exertion followed by a full minute of easy movement. For example, someone on a treadmill might run at full speed on an uphill angle for a minute, then walk at a moderate pace for a minute, and then run uphill again. Repeat the minute run and minute walk 10 times, and you are done.
Studies on Intense Interval Workouts
Years ago, studies on the effectiveness of interval workouts were conducted at McMaster U. with athletes who used interval training as part of their overall fitness regimens. The studies required the athletes to exert a 100-percent effort during 30-second intervals of hard training. The results showed that the athletes on the interval training regimen had the same muscle development as those doing hour-long workouts during the same time period. The interval workouts took 90 percent less time and produced almost identical results to traditional workouts.[ii]
Research Using More Realistic Interval Regimens
In the recent study, researchers shifted from athletes to average adults who did not exercise regularly. Half of participants in this second study were healthy, while half suffered from various forms of heart disease. Both groups were asked to exert a 90-percent effort for 60 seconds and then a low-intensity effort for 60 seconds, alternating over a period of 20 minutes. While each group reported the exertion was difficult, both groups reported they enjoyed these workouts more than traditional half-hour workouts. The workouts were intense, but the strenuous portions were short and manageable.[iii]
Marked Fitness Improvement of Heart Patients
Study results showed improved fitness levels over time for all participants. Researchers were surprised to find the heart patients showed a more substantial increase in fitness. They believe interval workouts are safer for the heart than extended workouts because the intense exertion is brief. The heart patients who completed the interval training experienced improvement in blood flow and their hearts were strengthened. These results indicate that heart patients might be able to enjoy the benefits of regular exercise without the cardiovascular dangers typically associated with exertion.[iv]
Surprising Impact on Blood Sugar Regulation
Researchers also discovered interval training improves blood sugar regulation. They noticed all participants had improved blood sugar metabolism
after a few weeks of training. Doctors began to research the effects of interval training on patients with Type II diabetes and were pleased to find these patients also responded positively to the training. Blood sugar regulation was improved after a single interval workout session, and the benefits lasted throughout the day.[v]
Longer Exercise More Beneficial Overall
While these health benefits are remarkable for those who are ill, doctors are quick to point out that most healthy adults who have the time will gain more benefits from a regular 30-minute workout than from an interval session. That said, the same doctors admit that when a person does not have the time to devote a full half hour to exercise each day, an interval session could be a good time-saving substitute. Interval training will produce results; while skipping your workout because your schedule is tight will not.
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