Dr. Pekka Oja of the UKK Institute for Health Promotion Research in Finland was curious about the idea.
"There is plenty of evidence showing that physical activity is good for our health," said Oja, lead author of the study published Tuesday in BMJ. "But (the World Health Organization) recommends generic physical activity, without specifics. We were interested in how sports could contribute to health and how different sport disciplines could benefit health."
Oja and his colleagues wanted to expand upon existing research about the benefits of physical activity. Some studies
have tested the effects of exercise intensity, suggesting that vigorous exercise, like running, has greater health benefits than passive exercise, such as walking to work. Other studies
looked at the short-term effects of exercise on health -- for example, how a six-week exercise program improved participants' well-being -- but they didn't show the long-term effects, Oja said.
What the researchers wanted to know was whether exercise really wards off death, either from cardiovascular disease or from other causes. They were also curious whether different sports keep us alive longer than others.
Physically active vs. physically inactive
Oja and his team gathered health data from over 80,000 individuals from Scotland and England for the study, which spanned nine years, from 1994 to 2003. Of the participants, a little more than half were female, with an average starting age of 52 for both groups.
At the start of the study, the participants took a survey assessing their physical activity habits, medical history and lifestyle (including education level, smoking and drinking frequency, and daily stress). About 45% met the physical activity guidelines
set by the WHO, which include 150 minutes of moderate-intensity aerobic physical activity a week for adults ages 18 to 65.
The physically active group was asked to describe their exercise routines: which activity they did, how often they participated and the intensity of their workouts.
The list of activities included cycling, swimming, running, football (called soccer in the United States), racquet sports (including badminton, tennis and squash) and aerobics (including gymnastics, Pilates and dance classes). The sports could be done at any intensity; for example, participants who commuted by bike to work and those who attended Spin classes both counted as cyclists.
Swimming was the most popular exercise, with 13.4% of participants reporting they swam. Nearly 15% of women swam, while almost 10% participated in aerobics. The least popular sport for women was football, played by 0.3% of the group. Men favored cycling over swimming -- 13% cycled while about 12% swam -- while aerobics was the least popular, participated in by about 2% of men.
After about nine years, the researchers tallied the number of deaths that had occurred. There were 8,790 deaths from any cause, including 1,909 deaths from heart disease. The researchers counted heart disease deaths only among those who developed the disease after the study began.
Full-body sports slash the risk of dying
Oja and his team compared the death rates between active and nonactive participants, and they found that any exercise was better than no exercise in terms of long-term health and longevity. If participants were active, no matter how, they reduced their risk of death by 28%.
But three sports in particular -- swimming, aerobics and racquet sports -- were linked to even stronger decreases in risk of death from both heart disease and other causes.
"Every one of these sports showed a significant association with (decreasing) mortality," said Oja.
Swimming, they found, was not only the most popular sport, it was one of the best exercises for health. Participants who swam reduced their heart disease risk by 41% and lowered their risk of death from all causes by 28%.
"I'm not surprised that swimming is the leader" in exercise, said Dr. Nieca Goldberg
, cardiologist and medical director of the Joan H. Tisch NYU Langone Center for Women's Health, who was not involved in the study. "It's a great aerobic exercise, and you use both your arms and legs."