The thousands of runner who took part had to be fit and healthy to compete in the London Marathon.
But one entrant was there to raise funds in memory of another fit runner who died unexpectedly.
Emma Ralston, a former pupil of Lesmahowgow High School, was raising money for CRY, Cardiac Risk in the Young, a charity which carries out research into sudden death in adults.
"Mark Gallacher was my brother Ryan's best friend, and close to our family," said Emma.
"He died in 2006 of Sudden Death Syndrome. He was only 21, so it struck us hard."
Mark was the son of Christine and older brother to Ben, of Hope Road, Kirkmuirhill.
A keen track and cross-country runner during his time at St John's Primary and Holy Cross High School, Mark had always led a healthy lifestyle.
So it came as a complete shock when this fit, young man died suddenly when his heart stopped during the night.
But Sudden Death Syndrome is not that rare. It is estimated that in the UK every week 12 'healthy' young people die from undetected heart conditions.
"When something like that happens, you think what could have been done to avoid it," said Emma.
Emma (28) had already taken part in shorter 10K events but decided to take the massive step of entering the London Marathon to raise funds for CRY, in memory of Mark.
The charity works to reduce the frequency of young sudden cardiac death and to improve screening facilities for heart conditions. CRY supports bereaved families, like Mari's, donates medical equipment and raises awareness of the cause.
Emma, who now lives in Glasgow where she works as an architect, trained for the marathon in the worst of the Scottish winter conditions, and on the day managed to complete it in four hours, three minutes and 10 seconds.
"It was a brilliant experience but very painful," she said afterwards. "I don't think anything prepares you for the pain at the end."
Sponsorship has been coming in steadily ever since the race ended.
Emma added: "I have over £2,000, which is much more than I ever imagined. Because the marathon was quite a big challenge it has been pretty good and because it was in memory of Mark people around the village have been really generous too."
Emma opened a Just Giving webpage for sponsorship. There is still time to make a donation to the charity at http://www.justgiving.co.uk/emmarathon
