More than 70 runners are expected to attempt an ultramarathon this weekend in Lydiard Park.
Participants will set off on the 50km Ultra Trail course at 7am on Sunday from Lydiard Park.
The course takes them to Broad Hinton, Chiseldon, Coate Water, Old Town, Purton and then back to Lydiard Park.
Matt Jones, who organised the day, believes it will be Swindon's first ultramarathon.
Matt said: "We will offer participants opportunities to offset their journeys, to plant a tree, and we will be litter picking all of our event routes before and after each event.
"It is definitely important companies like us do our bit to help with this climate crisis."
The endurance sport has recently become popular. In May, a report showed that global participation had increased by 345% in the last ten years.
Any distance more than the 26.2 miles of a marathon is deemed an ultramarathon and the longest recorded race spanned almost 5000km.
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