(RxWiki News) A key to reducing the risk of heart attacks in men may be engaging in vigorous exercise for at least three hours a week. A new study suggests that reduces their heart attack risk by 22 percent.
Researchers found there were several reasons for this -- most importantly the exercise helped boost good HDL cholesterol levels.
"Exercise regularly to reduce your heart risk."
Andrea Chomistek, a study author from the Harvard School of Public Health, said her research team decided to study vigorous exercise because of its stronger association with coronary heart disease. But in addition to determining that vigorous exercise reduced the risk of heart attack in men, investigators were able to partially determine why it lowered risk.
Chomistek said that 38 percent of the decreased risk was attributed to the benefits of exercise on a man's HDL or good cholesterol. Other factors included positive trends in vitamin D, apolipoprotein B and hemoglobin A1c.
Harvard School of Public Health researchers analyzed physical activity levels and biomarkers in 1,239 men who participated in the Health Professionals Follow-Up Study. The biomarkers investigated included cholesterol, inflammation and insulin sensitivity. Participants completed semiannual questionnaires about the average amount of time spent on leisure-time physical activity each week.
During the study period between 1994 and 2004, 454 participants suffered a nonfatal heart attack or died from coronary heart disease. Of those participants, 412 men with coronary heart disease were selected to be matched with 827 men without heart problems based on age, smoking status and other factors.
Chomistek noted that the men who suffered a nonfatal heart attack or died from heart disease had less good cholesterol and higher levels of bad LDL cholesterol. They also were more likely to have high blood pressure, high cholesterol and diabetes.
"Whether you are playing a set of singles in tennis, or lifting weights or running on a treadmill, when you exercise vigorously you create micro tears in arteries from the stress, and good cholesterol is released to heal those tears. So exercise of all kinds, both for men and women is beneficial in that it helps produce good cholesterol," said Jack Newman, chief executive officer of Austin Tennis Academy.
The study was published in the October issue of Medicine & Science in Sports & Exercise, the official journal of the American College of Sports Medicine.