You have probably said to yourself at sometime in the past, “If only I had the time and motivation to exercise for hours every day, my health issues and concerns would disappear – right?”
Wrong, according to a recent excessive exercise effects study conducted by researchers at Kansas City, Missouri’s St. Luke’s Hospital. In fact, cardiologist Dr. James O’Keefe and other researchers behind the study say that extreme forms of cardiovascular exercise can be detrimental to heart health, particularly in certain individuals.
The results of the study serve as unfortunate news for individuals who routinely participate in extreme endurance types sports such as triathlons, marathons and long-distance swimming and cycling races, to name a few.
However, it’s also good news for individuals who only have a moderate amount of time to devote to exercise, and whose primary goal is to improve health and fitness rather than train for competition. In fact, Dr. O’Keefe said that the vast majority of exercise benefits can be realized with less than an hour of exercise each day. “Extreme exercise is not really conducive to great cardiovascular health,” according to Dr. O’Keefe.
Excessive Exercise Effects on the Heart
O’Keefe points to various studies suggesting that extreme levels of aerobic endurance training can temporarily change aspects of the structure of the heart. The tissue can be stretched, and certain biomarkers associated with cardiovascular injury can rise. These changes typically resolve themselves within a week of the exercise session, though repeated sessions of extreme exercise can lead to heart scarring and other forms of permanent damage. In a study involving 100 otherwise healthy marathon runners, for example, it was discovered that 12% of them suffered from heart scarring, which is believed to affect just 4% of non-marathon runners.
Individuals with heart scarring are thought to be more susceptible to heart rhythm issues, according to the researchers. Excessive levels of exercise have also been linked with an enhanced risk of calcium buildup in the walls of the arteries, narrowing them in the process.
Other studies involving marathon runners have found that as many as half of the participants experience unusually high levels of B-type natriuretic peptide, an indicator of excess heart pressure, and troponin, a common indicator of heart injury. These compounds are usually most concentrated during and immediately following a marathon.
The Right Amount of Exercise
For optimal health, the American College of Sports Medicine advises all individuals to strive for either 75 minutes of vigorous exercise or 150 minutes of moderate exercise each week – in other words, a little over 10 or 20 minutes of daily exercise, depending on the intensity, though 30-minute sessions five days per week would likely be more ideal. Obviously, individuals who are actively trying to lose weight, for example, may exceed these recommendations temporarily as part of their fitness plan.
However, even individuals looking to loss weight would be doing a disservice to their health by greatly exceeding these figures, according to the St. Luke’s Hospital study. During the study, O’Keefe and other researchers found that individuals who ran a moderate distance, at a moderate level of intensity, three times per week enjoyed longer lives than individuals who ran longer distances with greater intensity (approximately 8 miles per hour) more than four times weekly.
The news could be highly motivational to potential exercisers who may have previously believed that intense, prolonged exercise sessions were the only path to better health. If O’Keefe’s study is to be believed, shorter, lower-intensity exercise sessions are actually more beneficial to health – so long as they’re performed with moderate (three times weekly) regularity.
Bad News for Endurance Athletes?
But what if your goal isn’t just to lose weight and stay healthy, but rather to actually compete in endurance sports such as marathons and triathlons? Will you be sacrificing your cardiovascular health just for a chance at competitive glory?
Maybe, but not necessarily, according to preventive cardiologist Dr. Suzanne Steinbaum of New York City’s Lenox Hill Hospital, who was not directly involved in Dr. O’Keefe’s study. Dr. Steinbaum says she would never strictly recommend against competing in endurance sports, citing the fact that just 1 in every 100,000 marathon participants die from sudden cardiac death, and the fact that encouraging any type of exercise could hardly be a bad thing in a population so overrun by obesity.
However, Dr. Steinbaum says that all endurance athletes should schedule a check-up with their heart doctor prior to participating in any serious training or competition. If existing levels of troponin or other biomarkers are found to be too elevated prior to exercise, endurance sports should probably be avoided.
Excessive Exercise Effects: The Bottom Line
Researchers at St. Luke’s Hospital in Kansas City, Missouri recently conducted a study finding that excessive amounts of exercise, such as what’s found in a training program for extreme sports including marathon running, can be detrimental to heart health.
The researchers also found that the vast majority of the benefits associated with regular physical activity can be gained through moderate exercise lasting approximately 150 minutes per week. Five weekly exercise sessions lasting 30 minutes each is ideal, according to the American College of Sports Medicine.
