Two very busy professionals I know took some time off last Sunday to go cross-country skiing. The snow was mushy from a recent thaw, and the legs of the skiers a bit wobbly but, according to my friends, it was a vigorous workout and welcome relief from their 80-hours week of work. They had fun, but they also were doing good things for their health. Like most too busy people, fitting physical activity into the workweek is like squeezing a suitcase into an overfilled overhead bin on an airplane. Often it is impossible to do it. A forty-something year old paralegal whose commute to work on a good day takes over an hour, told me that she is lucky because her workday runs only from 8:30 to 6. After she picks her children up at their nearby after school program, drives home, gets dinner ready, does the laundry and other household chores, helps the kids with their homework, and takes a few minutes to talk to her husband…. she is ready for bed, not for a treadmill. The lawyers in the office are lucky if they leave by 9 p.m.
The weekend may be the only time when a few hours can be used for exercise. But until recently, experts have said that exercising over only two days was insufficient to have much impact on cardiovascular health and eventually longevity. Rather, we have been told to be physically active almost everyday so that our total exercise time adds up to at least 150 minutes. And we should not assume walking to the car or commuter train station, strolling around the block with the dog, or taking out the trash meets the exercise requirement. We have to exercise with vigor: by running, climbing steps rapidly or taking a challenging aerobics class.
But now this assumption is being challenged. A recent article in JAMA Internal Medicine reported the results of an enormous study that collected information about the health and causes of death among 63,591 adults in England and Scotland from l994 to 2012. The subjects were asked about the amount of time they exercised weekly, when during the week they did exercise, and to rate how vigorous their exercise was. All this information was self-reported rather than observed by a researcher.
The study found that people who managed to squeeze 150 minutes of vigorous weekly exercise into two weekend days, rather than over 5-7 days, seemed to have the same cardiovascular benefits as the daily workout folk. Both these groups (and a third that did less than the guidelines) all showed about a 45 decrease in mortality due to cardiovascular events compared to the group that did not exercise.
The good news from these findings is that it removes the urgency in finding time to exercise during an already overextended weekday schedule. The bad news is that it is necessary to find time to exercise in an already overextended weekend schedule. The data showing such a significant decrease in the risk of dying from a heart attack, stroke or other cardiovascular cause are too compelling to ignore. On the other hand, filling up the refrigerator, doing the laundry, spending time with the kids, parents, friends, and catching up with bills, phone calls and sleep are too compelling to ignore as well.
It is possible to extract two-and-a-half hours of time to exercise out of 48 hours of “time-off.” That is less time than it takes to watch the Oscars, Super Bowl, or an average movie including previews. And doing so does not necessarily mean playing 150 minutes of tennis or a 2½-hour bike ride or run. Any physical activity, from shoveling snow to removing rocks from a potential garden, would qualify as exercise. And the exercise does not have to be done continually. A seven-minute workout following the instructions on an App or 2 minutes of jumping rope counts toward the 150 minutes.
However, there is a problem with the exercise recommendations. What is vigorous exercise?
If you are still breathing but unable to talk or sing, if your heart rate is high and you are sweating, then you are engaging in vigorous exercise. Straining to ride your bike up a steep hill and gasping for breath or running as fast as you can after a puppy that has just seen a squirrel and is heading for the street is vigorous exercise. Jogging with a friend and having enough breath to talk about a television show you saw last night isn’t.
Lists of what comprises vigorous exercise are meaningless to someone who is relatively unfit. A physically well-trained individual may have to do an hour of boot camp, sprinting around a track, or bike at high speed to break a sweat. However, most of us would find any physical activity that pushes us out of our comfort zone vigorous: climbing several flights of stairs, carrying heavy bags of groceries from the car to the kitchen, walking against a strong wind, or pushing a heavily laden shopping cart across a large parking lot. And for someone who rarely moves, climbing the stairs from the cellar to the second floor a few times each day may cause rapid breathing and heart rate.
Were those 63,000 subjects in the UK all doing vigorous exercise according to the definition of exercise physiologists? Or were some possibly a little vague about the vigor of what they were doing? Were they like some of us who, when asked about our weight and height, remove a few pounds from the former and add a few inches to the latter? Because if they were really engaging in moderate or even light exercise, “I can still breathe and talk” exertions, then it means that cardiovascular benefits are possible for those of us who may not break a sweat in the gym.