Runners in the Ben Nevis Race have been told to stick to the path by Scottish Natural Heritage (SNH), which fears competitors are eroding the greenery. The fastest runners take around one and a half hours to climb and descend the near 4,413ft mountain.
A section of the ten-mile course, around three-quarters of the way up the mountain, goes up what is called the Grassy Bank, and cuts around 60 yards off the main path.
Runners who take this route now risk disqualification from the race entirely.
An SNH spokesperson said: “We have been involved in discussions with the organisers of the Ben race to identify an alternative to the Grassy Bank.
“Key challenges are runners descending the steep grassy bank – and the associated fact that ground is steep and fragile, and so is eroding. If runners continue to descend the slope, particularly a narrow section in between two older landslides, there’s now a real risk of a large slope failure.”
Hill runners have expressed fears that the proposed changes, which make the route longer, will mean the course record of 1hr 25m 34s, set in 1984, would never be broken.
Ed Nicholas, who competes for Edinburgh-based club Hunters Bog Trotters, and completed the race in 2014, said: “The Ben Nevis record as it stands is a significant athletic achievement and has stood the test of time for over 30 years. The changes enforced by SNH will surely ensure that this won’t ever be beaten. The other issue is the number of people trying to beat the two-hour mark who will now struggle to do so. It remains to be seen whether the organiser will re-declare a new record on the new course.”
Mickey Whitehead, secretary of the Ben Nevis Race Association, admitted the changes would make the race more difficult.
He said: “It will make it a bit harder. In the 1960s somebody came down that way and everybody since has followed.”
The Ben Nevis Race is due to take place on 3 September with 600 athletes taking part.