Running has become a fashion, but risks also need attention
Mr. Xu, 36, works as a designer in the advertising industry. He often works overtime until late at night, and his irregular diet combined with prolonged sitting at a computer desk has led to an early "beer belly" at the age of 36. His blood pressure and blood lipid levels are also at critical levels. Recently, Mr. Xu decided to follow the example of his colleagues in the office and try jogging as a form of aerobic exercise for weight loss. However, the frequent reports of sudden deaths during long-distance running in the news have made him a bit worried. "Am I really suitable for running? What method should I use to start running?"
Professor Xu Dingli, director of the Department of Cardiovascular Medicine at Nanfang Hospital of Southern Medical University, said Mr. Xu's concerns are not unfounded. For ordinary healthy individuals without a fitness foundation, abruptly engaging in strenuous activities such as running over 1,000 meters or boxing requires careful control of heart rate to avoid cases of sudden cardiac death.
"Often, intense exercise with high intensity, extreme excitement of the sympathetic nervous system, and failure to replenish water and functional drinks in time after heavy sweating by athletes can lead to electrolyte imbalance—all of which may cause sudden death in beginners," Xu Dingli said. In addition, individual physical conditions, such as being in the inflammatory infection period of a cold, excessive fatigue, or even pre-run diet and hydration, may also trigger sudden death.
Beginners should pay attention to their maximum heart rate
For ordinary people, what level of running is considered strenuous exercise, and what is considered jogging? Xu Dingli said: "The four key elements of exercise—intensity, duration, type, and frequency—form the prescription for an aerobic exercise regimen. Monitoring heart rate is the easiest and most important indicator to determine whether the exercise intensity is appropriate."
Xu Dingli explained that during exercise, the heart rate of ordinary people should preferably not exceed 140–160 beats per minute, though this varies depending on age group and individual physical condition. For individuals like Mr. Xu, who aim to lose weight through aerobic exercise, the target heart rate in the aerobic zone should be between 60% and 80% of their maximum heart rate. All exercise intensity should prioritize the trainee’s own feelings—the target heart rate is just a reference. It’s also important to note the impact of certain medications on heart rate, so patients are best advised to seek professional consultation at hospitals offering cardiac rehabilitation services.
Xu Dingli said that patients with cardiovascular conditions can use treadmill or cycling tests to measure their maximum heart rate, and their exercise heart rate should preferably not exceed 70%–80% of their maximum heart rate.
Three steps to creating an exercise prescription
Sudden deaths during long-distance races generally stem from two causes: either the athlete has an underlying, hidden illness that doesn’t manifest under normal circumstances but flares up under intense exertion, leading to sudden death; or the athlete has a generally weak constitution, rarely exercises, and suddenly engages in high-intensity activity, triggering an “exercise stress syndrome,” with the most severe outcome being exercise-induced sudden death. Xu Dingli said that with adequate preparation before exercising, these hidden illnesses can be detected.
The first step is to undergo a cardio-pulmonary health check and an electrocardiogram stress test. Before exercising, a health check—primarily focused on cardio-pulmonary function—is essential. It’s also advisable to take an “electrocardiogram exercise stress test,” which helps diagnose whether the participant has any hidden heart conditions.
The second step is to understand your maximum heart rate and target heart rate. For beginners, it’s best to limit the first long-distance run to around 30 minutes, and it should preferably not exceed one hour.
The third step is to progress gradually. When engaging in long-distance running for fitness, it’s important to follow exercise principles: first and foremost, progress gradually. Additionally, warm-up exercises before running should be sufficient, and cool-down exercises are necessary afterward. If symptoms such as palpitations, shortness of breath, pale complexion, dizziness, blurred vision, or cold sweats occur during exercise, you should stop immediately.
Don’t push through discomfort while running
Experts point out that if your heart rate becomes too high during running, you can reduce your stride length and slow your pace—this is an effective way to lower your heart rate. However, stopping running abruptly is a dangerous move. During exercise, the heart cannot quickly adapt to such a sudden change and will continue to pump blood rapidly, causing blood to pool in the legs and reducing blood flow to other parts of the body, such as the brain. Mild effects may include dizziness after the run, while more serious consequences could trigger cardiovascular and cerebrovascular diseases.
Of course, some people still need to pay special attention to safety while running. For instance, older adults aged 50 and above, even if they do not experience any discomfort, are advised to undergo a professional medical evaluation before running to avoid triggering potential risk factors. Individuals aged 35 and above with high cardiovascular risk should also undergo comprehensive medical testing to help identify their true physical condition and the intensity of exercise they can safely undertake.
Xu Dingli also noted that the period from 6:00 to 10:00 a.m. is when the risk of sudden cardiac death is highest, so patients with cardiovascular conditions are advised to avoid morning workouts.