Policemen Jon Hewlett or PC Adam Leakey are tackling three marathons in three days for Children in Need.
PC Hewlett, 35, who lives in Marlborough is stationed in Swindon. He has always been a keen runner but says it is still a testing challenge.
PC Leakey, who lives in Swindon, is likely to find the marathons a tougher test as he is a novice runner who only started training in April.
Both have one child each and it was PC Leakey who came up with the idea of the triple marathon in three days.
PC Leakey said: “When I was growing up Children in Need is the one charity I can always remember watching on TV and thinking that one day I would like to do something for it.
“Earlier this year, in April, I decided to take up running. Until then I could barely run a mile.”
The marathons started in Marlborough this morning and ending there on Friday afternoon.
Mayor Edwina Fogg, who was accompanied by mace bearers Geoffrey Snelgrove and David Sherratt, waved off the runners from the town hall steps with members of both officers’ families watching.
The two bobbies ran from Marlborough along the A4, the Great West Road, ending their first marathon at Woolhampton near Reading.
On Thursday they plan to run from Woolhampton to Slough.
Their final 26-miler will be running from Woolhampton back to Marlborough.
PC Leakey said: “We hope to raise £10,000 and we have been pledge £5,300 so far so we hope we reach our target.”
The officers and their escort vehicle, driven by colleague PC Steve Hicketts, are collecting donations along the way and people can donate directly at www.justgiving.com/AdamandJonpudsey2012 or by text to PUDS80 £10 to 70070.