Daily exercise lowers men's risk of dying

Researchers have reported in Circulation: Journal of the American Heart Association that men who exercise reduce their risk of death. This reduction in risk applies to both African-American and Caucasian men (the research being conducted in the USA).

The study, funded by the Department of Veteran's Affairs included 15,660 participants and is the largest known study to assess the link between fitness and mortality.

The lead researcher, Dr Peter Kokkinos, PhD, who is also director of the Exercise Testing and Research Lab in the cardiology department at the Veterans AffairsMedical Center in Washington, DC stated, “It is important to emphasize that it takes relatively moderate levels of physical activity — like brisk walking — to attain the associated health benefits. Certainly, one does not need to be a marathon runner. This is the message that we need to convey to the public.”

Dr Kokkinos and his researchers studied the exercise capacity of the large study group of men (African-Americans - 6,749 and Caucasians - 8,911) as an independent predictor of overall mortality. They also looked at whether racial differences in exercise capacity had any influence over risk of death. The men's fitness was tested by a standardised treadmill test to assess exercise capacity between May 1983 and December 2006 at Veterans Affairs medical centres in Washington, DC, and Palo Alto, California. The men were encouraged to exercise until they felt tired and could not exercise any longer. If any of the study subjects developed any detrimental cardiac symptoms, they stopped the exercise and this was noted. The men in the study were also observed for 7.5 years, to record their death rates (when applicable).

The researchers classified the study subjects into various fitness categories based on their performance on the treadmill, by the peak metabolic equivalents (METs) achieved. Basically the MET is a measure of oxygen used by the body per minute and the higher the MET the more fit the individual. One MET is equivalent to the amount of oxygen a person uses at rest.

Based on the METs, the researchers divided the study participants into four categories, based on their level of fitness, from 5 METs (“low fit”), 5-7 METs (“moderately fit”), 7.1-10 METs (“highly fit”) and over 10 METs (“very highly fit”).

The researchers found that the “highly fit” men had about half the risk of death compared to the “low fit” men and the “very highly fit”men had a 70% lowered risk of death compared to the “low fit” men in the intervening 7.5 years. The researchers also found that for every 1 MET increase in exercise capacity, there was a subsequent 13% decrease of death from all causes.

Kokkinos said, “These findings are important for several reasons: First, we were able to quantify the health benefits per unit increase in exercise capacity. Second, this is the first study to provide information on physical activity and mortality in African Americans, information lacking until now. Keep in mind that death rates in African Americans are much higher when compared with Caucasians, in part because race and income negatively influence access to healthcare.”

“The Veterans Affairs’ health system is unique in that it ensures equal access to care regardless of a patient’s financial status,” he added. “Thus, it provides us with a unique opportunity to assess the impact of exercise or physical activity on death without the influence of healthcare differences.”

According to Kokkinos, most middle-age and older individuals can attain fitness levels with a brisk walk, 30 minutes per day, five to six days each week. “I do not advocate that everyone can start with 30 minutes of physical activity. In fact, 30 minutes may be too much for some people. If this is the case, split the routine into 10-15 minutes in the morning and another 10-15 minutes in the evening. The benefits will be similar if the exercise volume accumulated is similar,” he said

“Our findings show that the risk of death is cut in half with an exercise capacity that can easily be achieved by a brisk walk of about 30 minutes per session 5-6 days per week,” he added. “Physicians should encourage individuals to initiate and maintain a physically active lifestyle, which is likely to improve fitness and lower the risk of death. Individuals should also discuss exercise with their physician before embarking on an exercise program.”

American Heart Association