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MY IDEA OF EXERCISING is to do whatever I’m doing very efficiently so as not to devote unnecessary time or effort – but it turns out that one’s exercise choices change depending on the desired effect.
For one important goal — keeping weight down, or losing it when necessary, so I can eat pasta and ice cream for dinner – I have three aerobic activities: walking where I can be with friends, riding a stationary bike where I can read and swimming where I can stretch and enjoy the water. Since I do none of these before breakfast, however, I don’t achieve the increased fat burning that occurs “in a fasted state,” according to recent Belgian research.
At the rate I do each of these — low to moderate — based on a body weight of around 130 pounds, swimming uses the most calories, about 410 per hour, followed by cycling at around 275 an hour, with walking behind: even at 3.5 mph, which is considered a “brisk pace,” only 224 calories an hour.* I have considered doing any of these for about 45 minutes sufficient.
Aerobic exercise is associated with improving mood, reducing and even reversing the effects of aging on human skin, protecting against age-related vision loss and improving creativity. A recent study showed that “fit people were biologically younger than others of the same chronological age,” according to The New York Times.
My other goal: prevent cognitive decline, which exercise has been shown to stave off and in some cases reverse In a small study of women ages 70 to 80 exercising twice a week, the women who did resistance training, including lunges, squats and weights, did better on tests of selective attention and associative memory — associative memory is impaired in early stages of Alzheimer’s disease — compared to those who did moderate aerobic exercise.
The women doing aerobics increased the size of their hippocampi — the hippocampus is the area of the brain involved in verbal memory and learning and is sensitive to neurological damage associated with aging. But they did worse on verbal memory tests, a reversal from early studies that showed aerobic exercise improved brain health – a result that researchers suspect is due to the greater intensity of exercise in the earlier studies.
Intense is the new magic word. Several recent studies have shown that aerobic exercise accomplishes a lot more if it’s “intensive,” that is using 80 to 90 percent of one’s maximum aerobic capacity.
Whereas government guidelines for years have advised exercising most days at a moderate level of 30 minutes, or 15 minutes at a more vigorous pace, there has been very little science to support these numbers, Gretchen Reynolds writes in The New York Times. But in a study published last summer, researchers put together a huge database from which they chose 55,137 healthy men and women. Of these, 24 percent identified themselves as runners, and it turned out that the risk of dying from any cause was 30 percent lower for runners than for non-runners.
The runners’ risk of dying from heart disease was 45 percent lower, and “even overweight smokers who ran were less likely to die prematurely than people who did not run.” Duration was barely significant: those who ran 150 or more minutes /week didn’t live significantly longer than those who ran as little as five or ten minutes a day at 10 minutes/mile or slower.
The latest rage is HIIT, high intensity interval training — 30 to 60 seconds of intense exercise followed by a recovery period of easier activity, repeated for a total of about 20 minutes three times a week. HIIT increases the body’s ability to use oxygen efficiently, a good indicator of cardiovascular fitness, and the same for insulin – increases can occur after as little as two weeks of training. High-intensity exercise has also been shown more effective for patients with conditions like arthritis and heart disease. Another intense possibility is the “exercise snack:” one minute of “brisk” walking followed by one minute of strolling, repeated six times for a total of 12 minutes done three times/day. I try to imagine doing this: with a shower after each snack?
In a similar version of the snack tested in Japan over the past decade, intervals of three minutes of “somewhat-hard” walking followed by three minutes of strolling are repeated five times for a total of 30 minutes, at least three times a week. Compared to people who walked at a continuous, moderate pace, “the interval walkers significantly improved aerobic fitness, leg strength and blood-pressure readings,” according to this week’s New York Times Magazine.
The Japanese researchers offered the option of dividing each day’s total into 10 minutes in the morning, 10 in the afternoon and 10 in the evening. Other research has found that exercising for shorter times more often during the day can result in lower blood pressure and make it easier to lose weight.
Shortest of all is the “Scientific 7-minute workout,” which equals “a long run and a visit to the weight room,” according to Reynolds in the New York Times. The 12 positions use body weight, a chair and a wall, and include jumping jacks, lunge, side plank and others. They should be performed in rapid succession, with 30 seconds for each – again the key is intensity: “at about an 8 on a discomfort scale of 10,” with a 10-second rest between exercises, according to Chris Jordan, one of the workout’s developers. With frequency recommendations unclear, I worry that the workout should be done every day.
Intense and uncomfortable can be challenging. During an echocardiogram, I was put on an increasingly steep and fast treadmill until I could go no longer: my daily aerobic choices are nowhere near that intensity. The closest might be spinning class, which gets the blood vessels pulsating in my forehead but is so unpleasant it’s hard to consider doing more than a few times a year. And running, with my knees? Finally, I wonder how well short and intense deals with my pasta and ice cream requirement?
Another recent addition to the exercise equation: drinking 200 mg. of caffeine – a 12-ounce coffee or 32 ounce-tea, which sounds like too much caffeine for me – 15 minutes before a workout may help spur you on, because “caffeine causes muscles to release more calcium, which cues muscle fibers to contract with added force [so you] get this surge of I-can-do-it energy,” according to SELF magazine. Caffeine may also “dull signals from neurotransmitters in your brain that perceive pain,” Mark Tarnopolsky, M.D. at McMaster University told SELF.
Finally, whatever exercise you choose, the latest advice is to spend less time sitting — which has been shown to change the neurons that regulate blood pressure, effectively remodeling the brain — as in “sitting is the new smoking.” (See MyLittleBird’s, “Don’t Just Sit There.”)
For now, I’m trying to include intensity, a minute or two here and there, in my otherwise non-intense preferred activities — when I remember.
*adapted from research data from Medicine and Science in Sports and Exercise, the journal of the American College of Sports Medicine.
–Mary Carpenter
