People are increasingly recognizing the importance of exercise for health, whether it's hitting the gym at the community fitness center or going for a jog in the park. However, blind or excessive exercise can be harmful to the body, especially for those with chronic illnesses. At the 157th Xinmin Science Café, hosted by the Shanghai Association for Science and Technology, Dr. Wang Leming, President of Shanghai Tenth People’s Hospital and a cardiovascular disease expert, and Dr. Peng Yongde, Director of the Endocrinology Department and Diabetes Research Laboratory at Shanghai First People’s Hospital affiliated with Shanghai Jiao Tong University, shared insights on the science of exercise rehabilitation for chronic diseases with the audience. Additionally, a special guest — Zhang Leting, an amateur long-distance runner who has been running while using an insulin pump for years — also shared his experience with exercise rehabilitation.
Rehabilitation exercises should be precisely measured.
"Take medication on time, have regular checkups, and exercise moderately" — these are the three most common medical instructions patients with chronic diseases hear upon discharge. While the first two are relatively easy to follow, the last one, "exercise moderately," remains a vague concept. Dr. Wang Leming explained that different types and severities of chronic diseases — such as cardiovascular conditions, diabetes, and chronic pain — require each patient to have their own "exercise rehabilitation prescription."
Dr. Wang believes that scientific exercise is the best method for managing chronic diseases and secondary prevention. He introduced how Shanghai Tenth People’s Hospital began promoting "exercise prescriptions" for chronic patients, starting with cardiovascular disease patients. The core of this "prescription" is the cardiopulmonary exercise stress test, which evaluates cardiopulmonary reserve function. Under strictly controlled exercise loads, it analyzes indicators such as oxygen metabolism, ventilation, and hemodynamics during physical activity to understand the patient’s true exercise capacity.
"As the patient wears a sealed mask and gradually increases the intensity of exercise (usually on a stationary bike), we monitor various parameters in real time," Dr. Wang said. Among these, the anaerobic threshold (AT) in oxygen metabolism kinetics is particularly important. "After oxygen enters the body, it is pumped by the heart and distributed throughout the body via the bloodstream. After metabolism, it is converted into carbon dioxide and expelled. For patients, moderate aerobic exercise is safe, but when the exercise load increases to a certain point — where the body's tissues demand more oxygen than the circulatory system can supply — the body must rely on anaerobic metabolism to generate additional energy. This anaerobic metabolism is very dangerous for cardiac rehabilitation patients and can easily lead to sudden death during exercise. The scientific basis for a cardiac aerobic exercise rehabilitation prescription is to identify the turning point between aerobic and anaerobic metabolism, preventing the patient from entering a dangerous anaerobic state." According to him, the "exercise prescription" will select the appropriate form of exercise and define the intensity, duration, and frequency, adjusting the "prescription" every three months based on cardiac rehabilitation progress.
Dr. Wang added that currently, beneficiaries of the "exercise prescription" include patients with heart disease, hypertension, diabetes, and kidney dysfunction. Good forms of rehabilitation exercise include jogging or brisk walking, swimming or water walking, cycling, and resistance training.
Smart Exercise for Diabetics
According to Dr. Peng Yongde, among adults over 20 in China, one in four has abnormal blood sugar levels. China has become a major diabetes country, accounting for nearly half of the global diabetic population, posing a significant challenge to economic development.
Exercise is a powerful tool in diabetes treatment. Dr. Peng emphasized that there are specific considerations for diabetics when exercising: due to the risk of hypoglycemia, they should avoid exercising on an empty stomach and are advised to work out about half an hour after meals. Patients with high blood pressure should ensure their condition is under control before exercising. Those with proteinuria, retinopathy, or foot ulcers should exercise even more moderately — especially those with retinopathy, who must avoid bending their heads down during workouts. Individuals with foot problems should wear comfortable shoes.
An Enthusiast Shares His Exercise Journey
Zhang Leting, who traveled from Beijing, has had type 2 diabetes for 20 years. He started long-distance running 10 years ago and has kept it up since. In 2010, he was invited to participate in the Medtronic "Global Hero" marathon in Minneapolis, USA, where he ranked 658th out of over 7,000 participants. It is reported that this globally renowned long-distance running event for people with chronic diseases is currently recruiting participants for this year, accepting applications from "special" runners using medical devices from around the world.
Zhang Leting shared his exercise rehabilitation experience in simple terms: always exercise within your limits and never push yourself to 100% capacity. "At first, I only ran 400 to 500 meters a day, just enough to not feel tired, then gradually increased the distance. A year later, I started running marathons. Later, after consulting doctors, I learned that it’s best to run about 10 kilometers a day for around an hour. Recently, with heavy smog, I’ve reduced the frequency from daily runs to three times a week." He fully agreed with the experts' views: exercise should match one’s ability, and moderate activity based on personal fitness and bodily sensations is what truly benefits health.