Is There an Optimal Amount of Exercise for Cardiac Health?

ExerciseCardiacHealthSusan Brown Health and Wellness Editor

It’s well known that exercise, along with good sleep habits and proper nutrition, is one of the cornerstones of good health. Regular exercise helps to ward off diabetes, high blood pressure, cardiovascular disease and other chronic ailments. While studies have shown that too little exercise is not health supportive, a recent long-term study showed there may be a limit to the amount of exercise that is beneficial to cardiac health. Analysis of the results of a 25-year study suggests that low levels of exercise are linked to disease risk, that moderate levels reduce risk, and that high levels increase risk. As with Goldilocks and her porridge, it appears we need to find the level that’s “just right,” as excessive exercise may actually be damaging and detrimental for long-term heart health.

Coronary artery calcification (CAC), measured by CT scans, is known to be a strong predictor of future heart disease. While the researchers expected to see exercise linked to less calcification of the arteries, the findings revealed the opposite. The study found that those who exercised above and beyond the recommended moderate amount, had a 27 percent increased risk of developing coronary subclinical atherosclerosis by middle age. Another surprising finding was that Caucasian men who exercised at high levels were 86 percent more likely to have CAC levels higher than those who exercised the least. While it remains to be seen whether the individuals with these high levels of calcification will have more health problems as they age, previous studies have raised the question that extreme endurance activity may be linked to an increased risk of mortality.

Current research indicates that moderate exercise is the most beneficial for cardiovascualar health and overall wellness. Moderate exercise includes walking, jogging, swimming, and cycling among others. The ability to carry on a conversation during physical activity is a good indicator that you are not overstressing your heart. Heart-pounding exertion is simply not necessary if your goal is to maintain good health. Exercising for health, as opposed to competitive athletic fitness, takes surprisingly little effort to realize enormous benefits. Walking fifteen to thirty minutes daily can help with weight loss, lower both blood pressure and cholesterol, and reduce depression. It appears that health benefits of exercise plateaus beyond 45 – 60 minutes of daily moderate exercise. Those who enjoy exercise or participating in sports or dance, may exercise longer, but after the first hour, there are diminishing health returns.

Current U.S. guidelines recommend 150 minutes of moderate exercise, or 75 minutes of vigorous exercise each week. Set a goal of thirty minutes of moderate walking each day to reap the beneficial rewards of a healthier mind and body. Individuals who are time stressed, can accomplish this in three ten minute intervals and gain the same rewards. Every little bit of movement throughout the day is beneficial. Studies show that those who get at least some exercise, even if they don’t reach the minimum amount, still improve long-term health outcomes.

Physical activity intensity is determined by fitness levels. While brisk walking at 3 – 4 mph may be the ultimate goal, a pace of 3.0 mph may be ideal if your goal is weight loss and good health.  The moderate intensity zone is defined by exercising at 50%-75% of your maximum heart rate. In healthy persons, maximum heart rate may be determined by substracting your age from 220.

Those who are sedentary or have a health condition, should be sure to check in with their healthcare provider before embarking on a moderate intensity exercise program.

Guide to setting a walking pace:

  • Easy/Light: Leisurely stroll, effortless breathing, light intensity. At this pace, you should be able to sing.
  • Moderate: Purposeful, like you need to get somewhere, breathing more noticeable, light to moderate intensity. At this pace, you can speak in full sentences.
  • Brisk: In a bit of a hurry, breathing harder, moderate intensity. At this pace, you can still speak in full sentences, but may need to take more breaths.
  • Fast: Late for an appointment, hard effort, slightly breathless, moderate to vigorous intensity. At this pace, you can speak in phrases.

Excessive Exercise May Harm The Heart, Study Suggests.
How much exercise is optimal for heart health?
Can Too Much Extreme Exercise Damage Your Heart?
Physical Activity and Public Health.
Physical activity beneficial for CV health, but excessive exercise may confer harm.
25-Year Physical Activity Trajectories and Development of Subclinical Coronary Artery Disease as Measured by Coronary Artery Calcium: The Coronary Artery Risk Development in Young Adults (CARDIA) Study.