Is it possible to overdo it with sports? What are the risks of running 42 km and collapsing at the finish line?
By Prof. Gal Dubnov-Raz, MD, MSc, Director of Sports and Exercise Medicine, Sheba Medical Center
In recent years, there has been a significant increase in the number of marathon runners worldwide, including in Israel. It is estimated that there are currently more than 800 marathon races held around the world, and tens of thousands of runners participate in the largest ones.
In recent years, scientific evidence has mounted about the many health benefits of physical activity. Exercise has been shown to lower the risk of heart disease, stroke, hypertension, type 2 diabetes, dementia, depression, postnatal depression, obesity, falls in the elderly and several types of cancer.
There is little doubt about the positive health impact of physical activity, but some opinions question whether too much exercise can be unhealthy. Let’s take a closer look at marathon running.
The recommended amount of exercise is 150 minutes per week of aerobic exercise, such as walking, biking, swimming, ball games or medium-intensity aerobics studio sessions. If you are engaged in high-intensity activity, guidelines state that a minimum of 75 minutes per week is acceptable, and you can also combine different levels of intensity. In general, the more activity – the greater the health bonus.
Most of the casualties that occur during a marathon involve minor injuries, such as strains and sprains. Dehydration is the biggest threat that marathon runners need to conquer. On a hot day, a runner can lose up to four liters of fluid through sweating and exhaling, so keeping hydrated is a necessary precaution for all runners.
By following a training plan in the months leading up to a marathon, you can condition your body and get in good shape for the challenge. This type of planning, along with warming up and doing stretches, are good ways of avoiding many common injuries.
According to several scientific studies over recent years, running has shown itself to have superior health benefits over many other activities. The risk of death in runners is 30-45% lower, even when other risk factors for morbidity apply, such as smoking, obesity, alcohol consumption, socioeconomic status and more.
Studies that investigated the relationship between physical activity and mortality risks in the general population found that running an average of two hours daily does not raise the incidence of mortality.
The fears that some people have about excess physical activity are primarily due to the fact that several heart conditions have been associated with sprinting, such as fibrillation or heart attacks. However, the occurrence of these conditions is highly individual, and a doctor must examine and assess each separately to assess the person’s specific risk factors. The recommended amount of physical activity for each person should be adjusted accordingly.
A 10-year study conducted in the United States evaluated the incidence of mortality in more than 6,000 marathon races. At the time of the run or the day after, the mortality risk was about 1 per 100,000 mean, and 1 per 240,000 women who completed the marathon.
Regarding the road safety of a marathon, a study published in 2007 in the prestigious BMJ Medical Journal investigated the risk of mortality while running a marathon on closed roads compared to the risk of mortality from road accidents along the same stretch of road if the road had been left open for travel. The results showed that closing the roads for running was linked to a significantly lower incidence of mortality; statistically, an average of 1.8 lives were saved from having an accident.
Just like medicines taken at the wrong dose, very high doses of physical activity can pose some risks. It’s important to listen to your body and adjust your level of activity to your ability. Be sure to eat nutritiously, and go for medical follow-up exams. If you experience any pain, new and unexplained weakness, chest pain or difficulty breathing, seek medical attention.
Sheba Medical Center has a dedicated unit for Sports and Exercise Medicine, where you can receive personalized counseling and advice on a variety of topics related to physical activity. We treat patients of all ages and all levels of physical fitness, including professional, amateur and beginner athletes, as well as people who are healthy or ill.