An Ontario athlete has earned herself a Guiness World Record for running a marathon backwards.
Kat Clewley, who lives in Burlington, completed Hamilton's Road2Hope marathon in less than five hours, looking over her shoulder the entire way.
"I've done an Ironman, a lot of 100-mile runs, Boston Marathon, Mudderella, you name it," Clewley told the CBC. "This was the hardest thing I've ever done."
Clewley got the idea after jogging backwards to keep her an eye on her dog as they played fetch, said Canadian Running.
She Googled the sport, and realized there was a men's world record, but nothing for women, reported Running World.
So, she decided to try for a time of 4:30:00, with the run raising money for the YMCA's Beyond the Bell program for kids.
Next year, Clewley will represent Canada at the "retro-running" championships in Europe, said the CBC.
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Photos From The 2015 Boston Marathon
119th Boston Marathon(01 of39)
BOSTON, MA - APRIL 20: Lelisa Desisa of Ethiopa crosses the finish line to win the 119th Boston Marathon on April 20, 2015 in Boston, Massachusetts. (Photo by Jim Rogash/Getty Images) (credit:Jim Rogash via Getty Images)
Boston Marathon(02 of39)
Lelisa Desisa, of Ethiopia, crosses the finish line to win the Boston Marathon, Monday, April 20, 2015, in Boston. (AP Photo/Charles Krupa) (credit:ASSOCIATED PRESS)
Boston Marathon(03 of39)
Caroline Rotich, of Kenya, reacts after winning the women's division of the Boston Marathon Monday, April 20, 2015 in Boston. AP Photo/Elise Amendola) (credit:ASSOCIATED PRESS)
Boston Marathon(04 of39)
Caroline Rotich, of Kenya, breaks the tape to win the women's division of the Boston Marathon Monday, April 20, 2015 in Boston. (AP Photo/Elise Amendola) (credit:ASSOCIATED PRESS)
Boston Marathon(05 of39)
Caroline Rotich, of Kenya, reacts after winning the women's division of the Boston Marathon Monday, April 20, 2015 in Boston. (AP Photo/Charles Krupa) (credit:ASSOCIATED PRESS)
Boston Marathon(06 of39)
The elite men runners leave the start line of the Boston Marathon Monday, April 20, 2015 in Boston. (AP Photo/Steven Senne) (credit:ASSOCIATED PRESS)
Boston Marathon(07 of39)
Caroline Rotich, of Kenya, breaks the tape to win the women's division of the Boston Marathon Monday, April 20, 2015 in Boston. (AP Photo/Elise Amendola) (credit:ASSOCIATED PRESS)
Boston Marathon(08 of39)
Tatyana McFadden, of Russia, crosses the finish line to win the women's wheelchair division of the Boston Marathon Monday, April 20, 2015 in Boston. (AP Photo/Elise Amendola) (credit:ASSOCIATED PRESS)
Boston Marathon(09 of39)
Lelisa Desisa, of Ethiopia, leads the pack through Hopkinton, Mass., en route to a win in the Boston Marathon, Monday, April 20, 2015, in Boston. (AP Photo/Steven Senne) (credit:ASSOCIATED PRESS)
Boston Marathon(10 of39)
Runners approach the finish line in the rain during the Boston Marathon, Monday, April 20, 2015, in Boston. (AP Photo/Charles Krupa) (credit:ASSOCIATED PRESS)
Boston Marathon(11 of39)
Tatyana McFadden, of Russia, is congratulated after winning the women's wheelchair division of the Boston Marathon Monday, April 20, 2015 in Boston. (AP Photo/Elise Amendola) (credit:ASSOCIATED PRESS)
119th Boston Marathon(12 of39)
BOSTON, MA - APRIL 20: Caroline Rotich of Kenya, left, and Tirunesh Dibaba of Ethiopia race down Boylston Street during the 119th Boston Marathon on April 20, 2015 in Boston, Massachusetts. Rotich won the marathon with a time of 2:24:55. (Photo by Maddie Meyer/Getty Images) (credit:Maddie Meyer via Getty Images)
119th Boston Marathon(13 of39)
BOSTON, MA - APRIL 20: Shalane Flanagan of the United States runs down Boylston Street during the 119th Boston Marathon on April 20, 2015 in Boston, Massachusetts. Flanagan finished ninth with a time of 2:27:47. (Photo by Maddie Meyer/Getty Images) (credit:Maddie Meyer via Getty Images)
119th Boston Marathon(14 of39)
BOSTON, MA - APRIL 20: Race goers get their spots in Kenmore Square as they wait for runners as the Boston Marathon gets underway April 20, 2015 in Boston, Massachusetts. This is the 119th running of the Boston Marathon. Photo by Darren McCollester/Getty Images) (credit:Darren McCollester via Getty Images)
119th Boston Marathon(15 of39)
BOSTON, MA - APRIL 20: People in Kenmore Square wait for runners as the Boston Marathon gets underway April 20, 2015 in Boston, Massachusetts. This is the 119th running of the Boston Marathon. Photo by Darren McCollester/Getty Images) (credit:Darren McCollester via Getty Images)
Boston Marathon(16 of39)
Carlos Arredondo, left, a 2013 Boston Marathon first-responder, hands Tatyana McFadden, of Russia, a U.S. flag after she won the women's wheelchair division of the Boston Marathon, Monday, April 20, 2015, in Boston. (AP Photo/Charles Krupa) (credit:ASSOCIATED PRESS)
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Spectators cheer along the Boston Marathon race course, Monday, April 20, 2015, in Boston. (AP Photo/Robert F. Bukaty) (credit:ASSOCIATED PRESS)
Boston Marathon(18 of39)
Caroline Rotich, of Kenya, wins the women's division of the Boston Marathon, Monday, April 20, 2015, in Boston. (AP Photo/Charles Krupa) (credit:ASSOCIATED PRESS)
Boston Marathon(19 of39)
Caroline Rotich, of Kenya, wins the women's division of the Boston Marathon, Monday, April 20, 2015, in Boston. (AP Photo/Charles Krupa) (credit:ASSOCIATED PRESS)
Boston Marathon(20 of39)
From left, Yemane Adhane Tsegay of Ethiopia, Wesley Korir of Kenya, Tadese Tola of Ethiopia, Meb Keflezighi of San Diego, Lelisa Desisa of Ethiopia, Lusapho April of South Africa, and Nicholas Arciniaga of Flagstaff, Ariz., leave the start line of the Boston Marathon, Monday, April 20, 2015, in Hopkinton, Mass. (AP Photo/Stephan Savoia) (credit:ASSOCIATED PRESS)
Boston Marathon(21 of39)
Tatyana McFadden, of Russia, crosses the finish line to win the women's wheelchair division of the Boston Marathon Monday, April 20, 2015 in Boston. (AP Photo/Charles Krupa) (credit:ASSOCIATED PRESS)
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Tatyana McFadden, of Russia, holds her trophy after winning the women's wheelchair division of the Boston Marathon Monday, April 20, 2015 in Boston. (AP Photo/Elise Amendola) (credit:ASSOCIATED PRESS)
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Tatyana McFadden, of Russia, hoists her trophy after winning the women's wheelchair division of the Boston Marathon, Monday, April 20, 2015, in Boston. (AP Photo/Charles Krupa) (credit:ASSOCIATED PRESS)
Boston Marathon(24 of39)
Tatyana McFadden, of Russia, hoists her trophy after winning the women's wheelchair division of the Boston Marathon Monday, April 20, 2015 in Boston. (AP Photo/Elise Amendola) (credit:ASSOCIATED PRESS)
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Marcel Hug, of Switzerland, acknowledges the crowd while holding his trophy after winning the wheelchair division of the Boston Marathon, Monday, April 20, 2015, in Boston. (AP Photo/Elise Amendola) (credit:ASSOCIATED PRESS)
Boston Marathon(26 of39)
Tatyana McFadden, of Russia, crosses the finish line to win the women's wheelchair division of the Boston Marathon Monday, April 20, 2015 in Boston. (AP Photo/Elise Amendola) (credit:ASSOCIATED PRESS)
Boston Marathon(27 of39)
Runners, including Jeffrey Martin, center, of Edmonds, Wash., start the Boston Marathon, Monday, April 20, 2015, in Hopkinton, Mass. (AP Photo/Stephan Savoia) (credit:ASSOCIATED PRESS)
Boston Marathon(28 of39)
Runners including Chinh Le, foreground, of San Francisco, leave the start line of the Boston Marathon Monday, April 20, 2015 in Hopkinton, Mass. (AP Photo/Stephan Savoia) (credit:ASSOCIATED PRESS)
Boston Marathon(29 of39)
Runners leave the start line of the Boston Marathon Monday, April 20, 2015 in Hopkinton, Mass. (AP Photo/Stephan Savoia) (credit:ASSOCIATED PRESS)
119th Boston Marathon(30 of39)
BOSTON, MA - APRIL 20: A banner hangs near the finish line before the start of the running of the 119th Boston Marathon on April 20, 2015 in Boston, Massachusetts. (Photo by Jim Rogash/Getty Images) (credit:Jim Rogash via Getty Images)
119th Boston Marathon(31 of39)
BOSTON, MA - APRIL 20: First responder Carlos Arredondo poses at the finish line before the start of the 119th Boston Marathon on April 20, 2015 in Boston, Massachusetts. (Photo by Jim Rogash/Getty Images) (credit:Jim Rogash via Getty Images)
119th Boston Marathon(32 of39)
BOSTON, MA - APRIL 20: A view of a sign stating 'It All Starts Here' near the start in Hopkinton of the 119th Boston Marathon on April 20, 2015 in Boston, Massachusetts. (Photo by Maddie Meyer/Getty Images) (credit:Maddie Meyer via Getty Images)
119th Boston Marathon(33 of39)
BOSTON, MA - APRIL 20: A banner hangs in Kenmore Square as the Boston Marathon prepares to get underway April 20, 2015 in Boston, Massachusetts. This is the 119th running of the Boston Marathon. Photo by Darren McCollester/Getty Images) (credit:Darren McCollester via Getty Images)
119th Boston Marathon(34 of39)
BOSTON, MA - APRIL 20: A worker cleans the Finish line before the start of the 119th Boston Marathon on April 20, 2015 in Boston, Massachusetts. (Photo by Jim Rogash/Getty Images) (credit:Jim Rogash via Getty Images)
Boston Marathon(35 of39)
Spectators cheer for runners near the finish line of the Boston Marathon, Monday, April 20, 2015, in Boston. (AP Photo/Robert F. Bukaty) (credit:ASSOCIATED PRESS)
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Dustin Hicks, right, of Temple Terrace, Fla, walks with Laura Bowerman after proposing marriage to her at the finish line of the Boston Marathon Monday, April 20, 2015 in Hopkinton, Mass. (AP Photo/Elise Amendola) (credit:ASSOCIATED PRESS)
Boston Marathon(37 of39)
Lelisa Desisa, of Ethiopia, holds his trophy after winning the Boston Marathon Monday, April 20, 2015 in Boston. (AP Photo/Elise Amendola) (credit:ASSOCIATED PRESS)
Boston Marathon(38 of39)
Lelisa Desisa, of Ethiopia, holds his trophy after winning the Boston Marathon Monday, April 20, 2015 in Boston. (AP Photo/Elise Amendola) (credit:ASSOCIATED PRESS)
119th Boston Marathon(39 of39)
BOSTON, MA - APRIL 20: Lelisa Desisa of Ethiopa crosses the finish line to win the 119th Boston Marathon on April 20, 2015 in Boston, Massachusetts. (Photo by Jim Rogash/Getty Images) (credit:Jim Rogash via Getty Images)