People in cancer remission are being offered free entry to this year's New Forest Marathon.
The scheme, believed to be a first for a UK running event, is part of a wider effort to support recovery by promoting physical activity among those who have completed cancer treatment.
The decision follows new research showing that structured exercise after treatment can reduce the risk of mortality by a third.
The offer covers all race distances, from 5k to the full marathon, and is part of a structured training programme for cancer survivors.
Stuart Bowker, trustee at the Hampshire-based charity Run 4 Cancer, said: "For some time now, specialist cancer doctors have been extolling the benefits of exercise.
"Exercise can play a vital role in cancer recovery by improving mood and mental well-being whilst helping to manage fatigue and other treatment side effects.
"It can also help to maintain a healthy weight and assist in strengthening muscles and bones.
"However, the new evidence that exercise has the potential to significantly reduce the risk of cancer recurrence is of particular interest."
The scheme has been launched by Run 4 Cancer in partnership with the Garmin New Forest Marathon.
This year's event will take place on September 14.
Stuart said that the charity is encouraging people up to five years post-diagnosis to apply for a free place.
He added: "Of course, it is absolutely essential for people in recovery from cancer to speak with their doctor before embarking on any form of physical activity.
"People should only start training for one of the New Forest events if they have obtained medical sign-off."
To learn more or apply for a free place, visit www.run4cancer.org/new-forest-marathon.
Andy Dalsh, event director at the New Forest Marathon, said: "Run 4 Cancer is a long-standing partner of the New Forest Marathon.
"As one of our official charities, we fully support this fantastic initiative to help people in recovery from cancer."
He described the marathon as a "unique opportunity for people to take part in one of Europe's most spectacular running events."