Exercise & Fitness Archive

Research we're watching

While obesity presents a number of health risks for older adults, weight loss is often accompanied by a reduction in muscle tissue and loss of strength. A team led by researchers at Baylor College of Medicine set out to determine whether more exercise or specific types of exercise would help preserve muscle during weight loss.

The researchers randomly assigned 103 obese women and 57 obese men over age 65 to one of four groups. Three groups participated in a reduced-calorie diet plus one of three exercise programs — aerobic training, resistance training, or combined aerobic and resistance training — while the fourth, a control group, only received information on healthful eating.

A small study supports the idea that exercising improves body image, whether or not the activity leads to any visible change in appearance. This suggests that additional research examining different types of exercise, and the long-term psychological effects of physical activity would be valuable.

When it comes to heart health, there's a lot to love about racket sports.

If you haven't lobbed a tennis ball over a net since high school, you might want to pick up a racket again. A recent study suggests that people who play racket sports regularly may slash their odds of dying from a heart attack or stroke.

Tennis, which ranks among the world's most popular sports, provides an excellent full-body workout, plus a few other less obvious benefits. And lower-impact racket sports, such as badminton or table tennis, may be good choices for people who have certain health conditions or who are older (see "Ping-Pong, perhaps?").

In the journals

A study published online March 14, 2017, by The Journal of the American Medical Association suggests that when it comes to speed of recovery after a total knee replacement, a home-based rehabilitation program is as good as rehab that starts with a stay in the hospital.

Researchers randomly assigned people with osteoarthritis undergoing total knee replacement into two groups for 10 weeks of therapy. Those in one group received 10 days of hospital inpatient rehabilitation followed by a clinician-monitored program that they attended two to three times a week for eight weeks. Those in the other group skipped the hospital rehab and went straight into the clinician-monitored program but then progressed to at-home exercises.

Building strength and power is key to healthy aging, both physically and mentally. It may be easier than you think.

We probably don't need to remind you that your body changes with age. Age-related muscle loss begins at around age 35 and progresses slowly — at about 1% per year. But after about age 60, muscle loses mass more rapidly, so that adults who don't do regular strength training may lose 4 to 6 pounds of muscle per decade. Moreover, the lost muscle is usually replaced by fat.

Studies show that strength training not only can slow muscle loss, it can also help prevent or control conditions as varied as heart disease, diabetes, arthritis, and osteoporosis. And recent research indicates that it can also improve cognitive function, especially when added to aerobic exercise. As we age, strength training helps to preserve mobility and reduce the risk of falling. "What has been shown is that if you're looking at mobility problems, the most beneficial exercises that are those that focus on progressive training for strength and power," says Dr. Jonathan Bean, an associate professor of physical medicine and rehabilitation at Harvard Medical School.

News briefs

 Image: © Horsche/Thinkstock

A review of research published online April 24, 2017, by the British Journal of Sports Medicine suggests that physical exercise may help improve thinking skills in adults ages 50 or older, regardless of their mental performance when they started exercising. Researchers combed through 39 randomized controlled trials that looked at this age group. Most of the studies involved people who did aerobic exercise (the kind that gets your heart and lungs pumping, like brisk walking), resistance training (the kind that works your muscles and bones, like weight lifting), or a combination of aerobics and resistance training. A handful of the studies involved people who did yoga or tai chi. In all of the studies, participants took tests that measured various aspects of thinking skills — such as attention, working memory, and the ability to plan, organize, and manage time. All exercise types but yoga appeared to have benefits for the brain. The authors say the exercise regimen with the biggest brain boost was a combination of both aerobic and resistance-type training, of at least moderate intensity, for at least 45 minutes per session on as many days of the week as possible. The takeaway? Start exercising, and incorporate resistance training into your weekly routine.

On call

Q. I have heard that exercising on an empty stomach burns more fat and at a faster rate. Is this true?

A. When the body is in a fasting state, several backup mechanisms ensure your muscles and brain get the necessary sugar for fuel. During exercise, after your body's sugar stores are exhausted, the body then taps into stored fat and turns that into sugar or turns protein from muscle into sugar. This has led to the hypothesis that exercising when the body is already "sugar starved" will lead to more rapid fat burning.

Research we're watching

Earlier studies have shown that wrist-worn activity trackers can accurately record the number of steps a wearer takes. However, few studies have determined how well they monitor heart rate.

Researchers at the University of Wisconsin in Madison studied four wrist-worn activity trackers — Basis Peak, Fitbit Surge, Fitbit Charge, and Mio Fuse — to determine the accuracy of their heart rate monitoring in 40 healthy women and men ages 30 to 65. The researchers fitted each participant with four trackers—two on each wrist. Using the trackers as well as an ECG machine, the researchers measured the wearers' heart rates at one-minute intervals for 10 minutes while they were sitting. They then repeated the measurements while the participants walked on a treadmill for 10 minutes. When they compared the readings from the ECGs and the trackers, they found that all of the readings were more consistent when the participants were resting than when they exercised.

Despite willpower, many people find that making significant lifestyle changes is very difficult. Factors both internal and external influence our ability to make changes, but being aware of them is the first step to overcoming them.

Interval walking may improve endurance and help you get fit faster.

 Image: © Thomas MacDonald

Warm weather is here, and you may be walking more to take advantage of being outside. Why not ramp up your routine with bursts of fast-paced walking? The technique, known as interval walking, "is a great way to get the most exercise bang for your buck," says Dr. Aaron Baggish, associate director of the Cardiovascular Performance Program at Harvard-affiliated Massachusetts General Hospital.

About interval training

Interval walking is a form of interval training, which describes any form of exercise in which you purposely speed up or slow down at regular intervals throughout the session. The benefits of interval training in athletes and people in cardiac rehabilitation are well studied. Dr. Baggish says interval walking hasn't been examined as much, but he believes the same benefits apply. "Something about strenuous exercise is good for the body. It improves endurance, reduces blood pressure, and helps with weight loss," he explains.