( CNN ) -- Only a few hours had passed after the Boston Marathon bombing , which killed three people and injured hundreds , when this little nugget of inspiration showed up in my Twitter feed : . `` Back home . You know what ? I 'm going for a run . Definitely . '' That tweet is from Peter Vigneron , a writer who was at the marathon when the bombs went off . Luckily , as he writes on his blog , he was far enough from the blasts to be safe . As the hours went by I started to see more online posts like that -- runners in Boston and elsewhere making pledges to lace up their sneakers and hit the road . It felt like a groundswell of grass-roots action , a collective statement that this tragedy , no matter who perpetrated it or why , was n't going to stop people from doing what they love . iReport : Run for Boston 2014 . By Tuesday , people from Hong Kong , India , Canada , England , Croatia , Brazil , Mexico , Russia and the Netherlands were using the hashtag # runforboston and a Google doc created by CNN iReporter Becca Obergefell to log their journeys . The momentum has been building . As of early Tuesday afternoon , 360 people had logged more than 1,200 running miles on Obergefell 's page . People also have been sharing their stories with her . `` I ran to clear my head , but it did n't work . So I ran because I could . Because the freedom of running was n't taken away from me . Because the running community stretches to all cities and all places , and I 'm glad to be a part of it , '' one person wrote to Obergefell , a 26-year-old in Columbus , Ohio . I heard these stories and got inspired . That 's why I 'm pledging to run a marathon in honor of Boston -- and , since I 'm kind of a couch potato , I 'm going to pledge to do it by April 15 , 2014 , the 1-year anniversary of the tragedy . I 'd like to invite you to do the same . Sign up by going to the `` Run for Boston 2014 '' page on CNN iReport and uploading a photo of you and your running shoes . Alternatively , post the photo to Instagram or Twitter with the hashtag # runforboston and # cnnireport . If you 're so inclined , tell us why you 're running . You do n't have to pledge to run a marathon . Run a mile or a 5K -- or do a walk . The important thing is to get out there and get moving . Do it for Boston . Do it for your health . Or , if you use the simple app called Charity Miles , you can do it to raise money for one of the several worthy charities it features . I 'm doing it because I feel like I 've got to do something . It 's been 12 years since 9/11 and 18 years since the Oklahoma City bombing . I was safely miles away , in a middle school classroom , when a bomb exploded in downtown Oklahoma City , killing 168 . But that morning is stuck in my memory forever . I 'm running because I do n't want any of these tragedies to change me or to change us as a people -- to make us afraid , to keep us indoors . I am by no means a regular runner -- or even a runner at all . One of my friends saw a post about this idea on Facebook and thought I was joking . So please do n't feel shy about signing up to do something new . I have no idea what I 'm getting myself into -- and I think that 's probably a good thing , at least for now . CNN also hopes to make a video about the collective journey -- and I 'm running to see what it will be like to ( hopefully ) complete this challenge as a group . I could go on , but instead I 'm going to go take a photo with my sneakers . And then hit the sidewalk . I hope you 'll do the same . The opinions expressed in this column are solely those of John D. Sutter .
Runners are hitting the road in support of Boston bombing victims . Run : I 'm pledging to run a marathon by Tuesday ; join me . Sign up for the Facebook iReport challenge : Run for Boston 2014 . Run says the runforboston hashtag led to the challenge .