Tri3 Sleaford Triathlon Club, along with several members of other town sports clubs took part in the Equinox 24-Hour Run at Belvoir Castle in Leicestershire.
The event was held from noon on Saturday to noon on Sunday as a relay race following a 10km route round a challenging, hilly, off-road circuit.
Solo runners, pairs and teams participated to see who could do the greatest number of laps.
Two teams from Tri3 Sleaford ran a total of 420km in a mix of sunshine and showers.
The event is growing in popularity and welcomes all abilities and ages, with a 1.2km fun run for under 15s which was won by Tri3 Sleaford junior Will Bentley.
* For more information about the club, visit their website at www.tri3sleaford.co.uk or find them on Facebook at Tri3 Sleaford Triathlon Club.