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."
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."
Our hearts have to work harder during exercise that engages both our arms and legs, such as swimming or aerobics, Goldberg explained. Swimming also has the benefit of being nonweight-bearing, which makes it easier to do for a longer period and at a higher intensity without risking an injury.
However, Goldberg noted, it's important for swimmers to add some weight-bearing exercises to their routines to maintain bone density.
For overall health, she said, "You have to balance aerobic exercise with weight-bearing exercise."
Weight-bearing sports also showed impressive health outcomes. Aerobics, participated in most by women, slashed heart disease risk by 50% in the female group. Racquet sports players decreased their heart disease risk by 59% and their mortality risk from any cause by 47%.
Do cycling, running and soccer offer the same benefits?
Notably, cycling was found to lower the risk of death from any cause by 10%, but the sport did not significantly lower heart disease risk.
"I would have a look at cycling again, because other studies have said it's preventive of heart disease," Goldberg said. "This doesn't mean you should quit your Spin class."
She suggested that since the study took place in Europe, the participants may have been so familiar with commuting by bike that cycling was no longer an effective workout. Had the cycling group been divided between low-intensity cycling (such as commuting) and high-intensity (such as a Spin class), the results may have showed better health benefits for high-intensity cyclists, Goldberg said.
On the downside, running and football were not significantly linked to lower mortality risks compared with other sports. Runners had a 13% lower risk of death from all causes than people who weren't active.
This finding was surprising to the researchers, as running is frequently recommended as a longevity-boosting activity. One possible reason for the result is that runners did not stick to their program for the full study period, and therefore the sport didn't affect long-term health, Oja suggested.
"To benefit from exercise, the most important thing is to stay injury-free," Goldberg said. If possible, "a well-rounded mix of exercises is the best choice."
Any sport is better than no sport
Dr. Haitham Ahmed
, a preventive cardiologist at the Cleveland Clinic, said the most important finding of the study was that all exercise is good exercise.
"If you played any sport, you had a 28% risk reduction of dying of any cause," said Ahmed, who was not involved in the study. "Which means that exercise is good, no matter what you do and no matter which way you look at it."
Oja emphasizes that this research is "not meant to rank sports." Rather, his goal is to raise awareness that regular exercise and sports can significantly decrease someone's risk of death.
"We want to show that sports are healthy," Oja said. They're also fun because they also promote socializing, such as when groups meet for bike rides or aerobics classes.
In future studies, Oja would like to see a "more reliable number of subjects." One limitation of his study, he said, was that there was not enough participation in all of the sports groups to get a full comparison of the exercise effects.
Both Oja and Goldberg agree that when it comes to physical activity, any exercise will keep you alive longer than no exercise at all.
"One sport is not better than another," Oja said. "It depends on your liking" of the sport.
"If someone loves playing football, I'll tell him to keep playing football," Ahmed said. "The most important thing is to find what you enjoy doing and stick with it."
"Make sure you vary your exercise routine so you don't get bored," Goldberg added. "You have to find your own physical limit, and any aerobic exercise works."