The best exercise for many of us may not be the shortest, according to a new, challenging study that compares the health benefits of short, intense workouts at intervals with those of longer, smoother workouts.
The study, published in Medicine and science in sports and exercise, Concludes that each approach to exercise has its benefits, but that the effects on blood pressure, body fat, and other aspects of metabolism may be greater after standard workouts, half an hour and moderate, That workouts at quick intervals.
As we know those who follow fitness, high intensity interval training, or HIIT (High Intensity Interval Training), is seductive, fashionable and is a common theme in this column, as well as the exercise science.
HIIT, a mixture of extremely short periods of intense exercise followed by a minute or two of rest, it is fast and powerful, and studies show that a few minutes – or even seconds – of interval training can improve people’s health and longevity over time. .
But there are still many questions to be answered about the relative advantages of fast intervals over those of more traditional sustained aerobic workouts, such as brisk walking, running or cycling, Especially if someone is engaged in only one type of exercise and not the other.
Frequent moderate exercise is linked to improvements in blood pressure and glucose control. Photo Shutterstock.
So, recently, exercise scientists at the University of Guelph in Ontario began studying how people’s bodies change if they train exclusively at intervals or with standard and moderate workouts, following current exercise guidelines. .
Interestingly, many previous studies comparing short HIIT routines and longer moderate workouts did not adhere to formal exercise recommendations, because scientists wanted to match the frequency of workouts or other measures. Thus, the volunteers in these studies used to exercise three times a week, either completing a few minutes of HIIT or half an hour of brisk walking.
But the exercise guidelines for each type of activity differ. Medical and sports groups suggest that we do not train at intervals more than three times a week, to avoid the overexertion of muscles and cardiovascular systems, which means that if we exercise only with HIIT, we will be inactive four days a week or so. Comparable guidelines for moderate exercise suggest going out and moving at least five times a week and for at least 30 minutes at a time.
So Guelph’s scientists thought: what if people do HIIT three days a week and don’t do any other type of exercise than the other four, or train moderately five times a week?
To find out, they first recruited 23 sedentary and overweight adult men. They did not include women, out of concern that menstrual cycles would affect metabolic outcomes, but hope to include women in some larger future experiment.
They invited these men to the lab, measured their physical condition, body composition, and blood pressure, and asked them to take smoothies laden with large amounts of fat to see how their metabolism responded to the nutrient. They also placed blood sugar monitors on them to take home for a week and thus measure their daily monitoring of blood sugar, a measure of metabolic health.
They then asked half of the men to start training at intervals three times a week on exercise bikes in the lab, pedaling as hard as possible for 30 seconds, Resting for two minutes and repeating this sequence four to six times.
The other men began a typical moderate exercise program, cycling to the lab five times a week at a pace they could comfortably maintain. for 30 to 40 minutes.
Over the next six weeks, the HIIT group pedaled intensely for a total of less than an hour, while the moderate-intensity group exercised for at least 2.5 hours each week during the same period.
At the end of the six weeks, the two groups returned to the laboratory to perform new tests, after which the scientists examined the results for disparities. They found many.
differences
Almost all men were fitter, and more or less to the same extent, regardless of the exercise they performed. But only those in the moderate exercise group had come off a lot of fat body, they had improved their blood pressure or were more able to metabolize the extra fat from the unctuous smoothie.
Perhaps most interestingly, the control of everyone’s blood sugar at home was better only on the days they exercised, that is, three times a week for those who did HIIT-five for the moderate group. . The rest of the day, blood sugar levels tended to rise.
Taken together, the results indicate that intervals and traditional exercise alter our bodies in divergent ways, and we may want to consider what we hope to achieve with exercise when choosing the best way to exercise. says Jamie Burr, a professor at the University of Guelph, who conducted the new study with his graduate student Heather Petrick and other colleagues.
“The whole exercise is good”, Said Burr. But “there are nuances.” Frequent, almost daily moderate exercise may be preferable to improve blood pressure and continuous control of blood sugar, compared to infrequent intervals, he says, while a little HIIT is likely to put you in form with the same efficiency as hours and hours of easier pedaling or similar effort.
Of course, this study was on a small scale and in the short term, And in it participated only overweight and out of shape men, so we can not be sure that the results apply to the rest of the population. But the main lesson seems to be widely applicable.
“Move often,” Burr said, meaning that if you do HIIT today, you walk tomorrow.
By Gretchen Reynolds © The New York Times