The phrase “everything in moderation” has usually been associated with eating delicious-but-deadly foods, drinking alcoholic beverages, and other obvious activities that can be dangerous in excess. However, this popular adage apparently also applies to exercising.
A new study shows that highly strenuous exercise (at least seven-and-a-half hours per week of physical activity) can be a factor in developing heart disease. Researchers at the University of Illinois at Chicago and Kaiser Permanente assessed exercise patterns over the course of 25 years and found that men with a high-intensity workout regimen are 86 percent more likely to develop a buildup of plaque in their arteries by middle age. However, the findings reveal that this is true for white men, but not black men.
The research team spent 25 years, from 1985 through 2011, analyzing data from participants starting at age 18 to 30 and finishing at 43 to 55. They assessed the physical activity trajectories of 3,175 black and white men and looked for the presence and amount of coronary artery calcification (CAC), a red flag indicating a risk at developing heart disease. The researchers expected low levels of CAC associated with higher levels of physical activity, but the study reveals the opposite – there is apparently an 86 percent increase in risk for white men at top level of exercise, but no extra risk for black men.
The participants were split into three distinct groups, according to their exercise patterns:
- Group one exercised below the national guidelines of 150 minutes a week;
- Group two met the national guidelines of 150 minutes a week; and
- Group three exercised three times above the national guidelines, over 450 minutes a week. (Related: Exercise-induced migraines can be avoided with aerobic exercise.)
The study concludes that those in group three were 27 percent more likely to develop CAC by middle age. The findings were then further analyzed according to race and gender, and showed that white men were at an 86 percent higher risk of CAC buildup. A similar trend was observed with white women, though this has no statistic significance.
Dr Deepika Laddu, assistant professor of physical therapy in the UIC College of Applied Health Sciences, said: “Because the study results show a significantly different level of risk between black and white participants based on long-term exercise trajectories, the data provides rationale for further investigation, especially by race, into the other biological mechanisms for CAC risk in people with very high levels of physical activity.”
Study co-author Dr Jamal Rana, a cardiologist at Kaiser Permanente in Oakland added: “High levels of exercise over time may cause stress on the arteries leading to higher CAC.
“However this plaque buildup may well be of the more stable kind, and thus less likely to rupture and causes heart attack, which was not evaluated in this study.”
Despite these findings, the researchers still encourage people to exercise. The key is in moderation.
The findings are published in the journal Mayo Clinic Proceedings.