Which athletes live the longest?

You already know that exercise is good for you, but are some sports better at keeping the grim reaper at bay?

One of the most significant scientific studies focused on the question came out of Scandinavia in 1993. Researchers divided 2,613 elite male Finnish athletes into three groups -- endurance athletes (long-distance runners and cross-country skiers, for example), and power athletes (boxers, wrestlers, weight lifters) and a mixed group of team athletes (like soccer, ice hockey or basketball players) and sprinters. The researchers then compared those male athletes to 1,712 Finnish men who were not competitive athletes. The power athletes lived an average of 1.6 years longer than nonathletes, team athletes lived four years longer and endurance athletes lived 5.7 years longer [source: Sarna et al.].

Let's consider what sets endurance sports apart. The American Medical Association published a study in 2001, looking at VO2 max, the maximum amount of oxygen a particular body can take in during exercise. Sports requiring a high VO2 max make you breathe the hardest -- such as running or biking -- as your body tries to get precious oxygen to your muscles. The study showed elite athletes had a lower chance of dying at a given age than nonathletes, but how much lower depended on VO2 max. Endurance athletes had a 43 percent lower chance of dying at a given age than nonathletes. Team athletes had 33 percent less risk, while power athletes whose sports don't require a high VO2 max, only got a 10 percent protection [source: Kujala et al.].

These studies don't cover every angle, though. Scientists gathered information about the cause of death and age of each participant, but they didn't consider what the men had done after they stopped competing in sports. Competitive athletes are generally young -- the average age of NFL players is 27 [source: Sando]. Studies have shown that staying active throughout your entire life is a very big deal when it comes to your health, so the math geek who takes up running after college and keeps at it will probably live longer than the football hero who hangs up his cleats and hits the recliner once his glory days are over [source: Paffenbarger].

Don't count team sports and resistance training out, either. They may not boost longevity quite as much as endurance sports, but they are an important part of the picture. Team sports can teach youth about discipline, camaraderie and sportsmanship, and are a healthy way to bond with friends. Resistance training helps prevent muscle wasting that happens with aging and reduces strength, coordination and quality of life during a person's golden years [source: Johnston et al.]. Resistance training also strengthens bones for a healthy life [source: Kravitz]. Cross-training helps prevent overuse. Varying your workout will keep you from getting bored and let you tap into the unique benefits of different types of exercise.

Some sports can actually present a threat to longevity. Which ones? Read on to learn more.

All sports have their health benefits, but those benefits come with risks, too. Sports injuries sometimes require surgeries and can lead to lifelong pain for some athletes. Repetitive motion injuries are a serious risk in some sports, and can have life-changing consequences. Scientists in England found that professional soccer players are 10 times more likely to develop arthritis in the hip than the general public. Surprisingly, most of the players who developed arthritis did not realize they were injuring their hips -- the arthritis was caused by repetitive motion. Many professional soccer players require total hip replacements in their 30s or 40s, which is much younger than most hip replacement patients in the general population. Dartmouth-Hitchcock Medical Center in New Hampshire reports that the average age of its hip replacement patients is 64 [sources: Shepard, Banks & Ryan; Dartmouth-Hitchcock Medical Center].

Another significant danger in some sports is traumatic brain injury (TBI). TBI can be disabling or even life-threatening -- actress Natasha Richardson died in 2009 after she hit her head while skiing, and world-class halfpipe snowboarder Kevin Pearce was critically injured during training late that same year. Pearce was rushed to the hospital in critical condition and placed on a respirator after he hit his head on the ice; he spent over three months in the hospital and many more months in rehabilitation. He was wearing a helmet at the time of the accident [source: Branch].

Athletes who suffer brain injuries can continue to get sicker even years after they stop playing their sport. Dementia pugilistica is a degenerative brain disorder caused by repeated blows to the head that was first diagnosed in boxers. This disease causes severe mental and physical disabilities; it can mimic Parkinson's disease or Alzheimer's disease, and it continues to get worse until the patient dies. Heavyweight boxer Jerry Quarry, who fought Muhammad Ali, died in 1999 at age 53 after severe dementia pugilistica left him confused, childlike and unable to care for himself [source: CNN/Sports Illustrated]. The risk of dementia pugilistica makes boxing less than a sure bet for living longer.

Even mild concussions can cause memory problems, confusion, depression and personality changes, and medical experts still don't know the long-term effects of repeated mild concussions. College football players with a history of three or more concussions are three times more likely to suffer another concussion than their teammates, so repeated concussions are a concern for football players [source: Guskiewicz].

Besides injuries, some competitive athletes do things to their bodies in their efforts to win that can shorten their lives. Anabolic steroid abuse can cause heart damage and suicidal behavior. Competitive wrestlers have died of dehydration and heatstroke from trying to lose water weight by abusing laxatives or trying to "sweat out" pounds before meets so they can compete in a lower weight category. Football players who play positions in which being heavier is an advantage, such as offensive and defensive linemen, often put themselves at risk for obesity-related disease. In a 1994 study for the National Institute for Occupational Safety and Health, Dr. Sherry Baron found that NFL offensive and defensive linemen had a 52 percent higher chance of dying from heart disease than the general population. Many of those heavy linemen died before age 50 [source: Hargrove].

The bottom line is that while endurance athletes tend to have the greatest longevity -- endurance, team and power sports all have their own benefits and risks. It's important to play safely and weigh a sport's health benefits against its potential dangers. If you're a competitive athlete, do plenty of cross-training and reap the benefits of other sports. If old sports injuries limit your options, take up a no-impact sport like swimming or biking. The key is to make exercise a regular part of your life -- all of it -- for a longer, healthier life.