As we age, even if we're healthy, the heart just isn't as efficient in processing oxygen as it used to be. In most people the first signs show up in their 50s or early 60s. And among people who don't exercise, the changes can start even sooner.

"Think of a rubber band. In the beginning, it is flexible, but put it in a drawer for 20 years and it will become dry and easily broken," says Dr. Ben Levine, a heart specialist at the University of Texas. That's what happens to the heart. Fortunately for those in midlife, Levine is finding that even if you haven't been an enthusiastic exerciser, getting in shape now may help improve your aging heart.

Levine and his research team selected volunteers aged between 45 and 64 who did not exercise much but were otherwise healthy. Participants were randomly divided into two groups. The first group participated in a program of nonaerobic (无氧) exercise—balance training and weight training—three times a week. The second group did high-intensity aerobic exercise under the guidance of a trainer for four or more days a week. After two years, the second group saw remarkable improvements in heart health.

"We took these 50-year-old hearts and turned the clock back to 30-or 35-year-old hearts," says Levine. "And the reason they got so much stronger and fitter was that their hearts could now fill a lot better and pump (泵送) a lot more blood during exercise." But the hearts of those who participated in less intense exercise didn't change, he says.

"The sweet spot in life to start exercising, if you haven't already, is in late middle age when the heart still has flexibility," Levine says. "We put healthy 70-year-olds through a yearlong exercise training program, and nothing happened to them at all."

Dr. Nieca Goldberg, a spokeswoman for the American Heart Association, says Levine's findings are a great start. But the study was small and needs to be repeated with far larger groups of people to determine exactly which aspects of an exercise routine make the biggest difference.

A trial project by the Montreal Children's Hospital suggested that the use of medical hypnosis(催眠)can reduce pain and anxiety in patients. The project also resulted in a reduction in the amount of medicines used to perform medical-imaging imaging(医学影像) procedures.

"During the examination children don't move. It works perfectly. It's amazing," said Johanne L'Ecuyer, a medical-imaging technologist at the hospital.

The project was inspired by a French team from Rouen University Hospital Centre where examinations are done under hypnosis instead of general anesthesia(麻醉).

A French medical-imaging technologist-also a hypnotist — was invited to train a few members in the medical-imaging department of the children's hospital. In all, 80 examinations were conducted for the project between January and September, 2019, focusing on the imaging procedures that would cause anxiety.

Hypnosis is not a state of sleep: It is rather a modified(改变的)state of consciousness. The technologist will guide the patient to this modified state—an imaginary world that will disassociate itself more and more from the procedure that follows.

"The technologist must build up a story with the patient," Ms. L'Ecuyer said. "The patient is left with the power to choose what he wants to talk about. Do you play sports? Do you like going to the beach? We establish a subject that we will discuss throughout the procedure. "

Everything that happens next during the procedure must be related to this story — an injection (注射) becomes the bite of an insect; the heat on the skin becomes the sensation of the sun and a machine that rings becomes a police car passing nearby.

"The important thing is that the technologist associates what is happening outside the patient's body with what the patient sees in his head," Ms. L'Ecuyer said. "It requires creativity on the part of the technologist, imagination, a lot of patience and kindness."

The procedure appealed to the staff a lot when it was introduced in January. It spread like wildfire that someone from France was here to train the technologists," Ms. L'Ecuyer said. She added that she had a line of staff at her door wanting to take the training.

    Race walking shares many fitness benefits with running, research shows, while most likely contributing to fewer injuries. It does, however, have its own problem.

    Race walkers are conditioned athletes. The longest track and field event at the Summer Olympics is the 50-kilometer race walk, which is about five miles longer than the marathon. But the sport's rules require that a race walker's knees stay straight through most of the leg swing and one foot remain in contact (接触) with the ground at all times. It's this strange form that makes race walking such an attractive activity, however, says Jaclyn Norberg, an assistant professor of exercise science at Salem State University in Salem, Mass.

    Like running, race walking is physically demanding, she says, According to most calculations, race walkers moving at a pace of six miles per hour would burn about 800 calories(卡路里) per hour, which is approximately twice as many as they would burn walking, although fewer than running, which would probably burn about 1,000 or more calories per hour.

    However, race walking does not pound the body as much as running does, Dr. Norberg says. According to her research, runners hit the ground with as much as four times their body weight per step, while race walkers, who do not leave the ground, create only about 1.4 times their body weight with each step.

    As a result, she says, some of the injuries associated with running, such as runner's knee, are uncommon among race walkers. But the sport's strange form does place considerable stress on the ankles and hips, so people with a history of such injuries might want to be cautious in adopting the sport. In fact, anyone wishing to try race walking should probably first consult a coach or experienced racer to learn proper technique, she says. It takes some practice.