( CNN ) -- Amanda Wagner and Jessica Tuttle turn 50 this year , but they 're not letting age hold them back from their favorite exercise : running . They 've been lacing up their running shoes since their teens and show few signs of slowing down . Research on older runners suggests they may not have to . Jessica Tuttle , 50 , left , and Amanda Wagner , 49 , have been running for more than 30 years . `` It 's a little bit harder , but that 's part of the challenge I think , '' says Wagner . When she is n't traveling for her job at a pharmaceutical company , Wagner tries to get together with Tuttle for 45-minute pre-work runs three to five days a week . Tuttle , who is a medical epidemiologist at the Georgia Health Department , feels that running gets her day off to a good start . `` It really wakes me up in the morning , '' says Tuttle . `` It gives me an edge when I go in to work . '' Conventional wisdom holds that the pounding from years of running leads to excessive wear and tear on the body as we age , resulting in joint injuries , knee replacements or arthritis . So-called weekend warriors -- people who are n't in the type of shape needed to safely run sprints , dive for passes or make cuts on the basketball court -- add to this misconception when they hobble into their doctors ' office after an injury . But a study out of Stanford University that looked at healthy aging runners found that running did not damage joints or leave runners less able to exercise . Researchers discovered that if you 're healthy and generally free of injury , there are few reasons to put away your running shoes , even into your 70s and 80s . Watch more on running as you age » . `` Moderate [ running ] , three to five miles at a time , three times a week will actually help your joints to be more resilient and function a little bit better , '' says Dr. Amadeus Mason at Emory Sports Medicine Center in Atlanta , Georgia . But he stresses that keeping the joints healthy in the first place may be the key to running longevity . That includes not running through pain , and resting if you have an injury , something Tuttle takes seriously . `` I try to rest maybe if I 'm having some specific pain that seems to be over a couple of days , '' she says . Mason also warns against running if you suffer from a chronic knee injury . In this case , the continuous pounding could accelerate damage and lead to arthritis . Instead , choose joint-friendly exercises such as swimming , walking or a workout machine such as the elliptical . Even if you have remained healthy , as Wagner and Tuttle have , do n't get overzealous and overdo it . `` The biggest risk that runners will face as they age , with regard to injury , is overtraining , by far , '' says Mason , who recommends giving yourself a day of rest between runs , or cross-training on the non-running days . In addition , Mason advises wearing the proper footwear and making sure to stretch before and after a run . Beyond the good news about aging joints , the Stanford researchers also discovered some surprising overall health benefits for senior runners when they compared them with non-runners of the same age : Those in the running group were less likely to die from heart trouble , stroke , cancer , neurological diseases or infection . Watch Dr. Gupta explain the study findings » . `` The survival rate of the runners was again twice that of the controls , '' study author Dr. Eliza Chakravarty says . She says the findings were a surprise to the researchers . Additionally , runners enjoyed a better day-to-day quality of life in old age than their more sedentary peers . `` Members of the running group , it took them 16 years longer to reach certain levels of disability , '' says Chakravarty . `` Running is not the only thing that 's going to make you live longer and be healthier ; it 's actually probably engaging in any kind of exercise that people enjoy , '' notes Chakravarty . `` It 's never too late to start incorporating regular exercise into your routine ... health benefits can last for decades . '' But running is still the exercise of choice for Wagner and Tuttle , who have remained relatively injury-free throughout their 30-year running careers . The women do n't plan to hang up their running shoes any time soon . `` I really ca n't imagine not running ; it 's that much a part of my life , '' says Wagner . `` And I do expect and hope to be running when I 'm 60 and when I 'm 70 -- I truly do . ''
Stanford University study finds that running did not damage joints in aging people . Runners still need to take precautions : Do n't run with shoes , wear proper shoes . Runner is less likely to die from certain injuries , he says .