Guide Dogs has launched a fundraising version of the recent BBC series in which members of the public undergo training for the SAS.
Colin Hill, Guide Dogs' sports and overseas events manager, came up with "Escape and Evasion
for the charity after reaching the final of SAS - Are you tough enough?.
More than 700 people have signed up for the event since Guide Dogs began advertising last week. Ex-SAS men will oversee the competition, which will take place in the Brecon Beacons during August and September.
Hill said: "There are so many people who feel inspired to take part in this event which will test their physical fitness and stamina to the limit. The event will feature survival techniques, shelter building, avoiding capture, camouflage and concealment. Given the response, we will be holding similar events in the future."
For details on how to take part, visit www.saschallenge.org.uk.