Protests have greeted plans to cut short part of an Ironman challenge in the borough.
Promoters of Ironman Bolton, which begins at Pennington Flash and travels through Leigh, Parbold and Standish, have cut the cycling leg by 17 miles, due to the impact of the Winter Hill wildfires.
This has reduced the ride from 112 miles to 95 miles, avoiding part of the moors, which have been smouldering for a fortnight.
But competitors, who paid a £400 entry fee and have trained for months for the triathlon have besieged the organisers’ Facebook account, urging them to reconsider.
Ian Hoffman, from Bristol, said: “I’m sorry Ironman but this is disgusting.
“You built your entire brand around the challenge of becoming an Ironman for which you plaster the distances all over the place. Then take away the opportunity to do that on six days notice.
“After 30 weeks of early weekend starts, battling through wind, rain, snow, hail, three Beasts for the East, missed events, poor sleep, essentially structuring your life around the commitment to this challenge, to have it taken away this close is crushing.”
But Craig Green added: “They have so much planning to do, so much deliberation with council and locals to ensure the event is a go. Let alone the safety aspect of smoke inhalation.”
Toxic blue-green algae, harmful to the skin, has also been recorded at Pennington Flash, which hosts a 2.4 mile swim to kickstart the event.
Ironman spokesman Michael Flanagan said: “All events are subject to change due to external occurrences and with this year’s race affected by wildfires, the changes are necessary for the race to safely proceed.
“While we sympathise, we aim to continue to deliver an athlete experience to its fullest possible extent. Unfortunately, the environmental effects on Ironman UK have occurred beyond our control and our team, who have planned and prepared for the race for more than a year, do not take lightly this decision to change the planned course.”