Tens of thousands of runners took to the streets of Dublin on Bank Holiday Monday for the marathon.
The 26.2 mile test is one of the most arduous of one's physical ability and in the field, we're sure, will be a smattering of the country's top cyclists.
Plenty of cyclists take to running after they hung up the wheels while some still do both.
Here, we looked at some of the quickest marathon times set by well-known Irish riders.
Rory Wyley, Carrick Wheelers
Major cycling achievements: Two-time Des Hanlon Memorial winner.
Marathon PB: “I did 2:34:56 but got sent the wrong way which cost me around a minute.”
When?: Polytechnic Marathon which was held in the early 1990s between Windsor and Chiswick in London.
Will Byrne, Murphy Surveyors Kilcullen
Major cycling achievements: Two-time national hillclimb champion, national track champion (scratch race), Leinster RR champion, 8th overall Girvan Three-Day (riding for Irish team).
Marathon PB: 2.49.29 in Berlin, September 2015
Why?: “I was looking for a change and five years ago the duathlon scene was starting to take off so I took that up.
“I've medalled in my age group this year and have qualified for the European Championships in 2016.”
Tim Barry, Aquablue
Major cycling achievements: Kerry Group Ras Mumhan, Shay Elliott, Tour of Ulster, Tour of Connacht, Visit Nenagh Classic, multiple team prize winner from the Rás.
Marathon PB: 3.03 Dublin, 2014
How was it?: “The biggest mistake cyclists make is that they underestimate how hard and long it takes to train up to doing a sub 3-hour marathon.
“I got caught short - had a sh1t in someone’s garden - at around mile 15 and that didn't help me.
“Bill Moore (Ras stage winner in 2005) nearly gave me a heart attack at mile 24 when he jumped off the footpath to give me a cheer!”
Paul Griffin
Major cycling achievements: Four-time Irish national hill-climb champion, Rás Connachta, two-time Lacey Cup winner, multiple Rás Mumhan stage winner, Tour of Ulster stage winner, Des Hanlon Memorial winner.
Marathon PB: 2:56:47, Dublin, 2015.
Current plans: Griffin ran Monday's marathon to raise money for his nephew, Michael Hickey, who was born prematurely and has since been diagnosed with Spastic Quadriplegia.
“He's off to St. Louis in the US in December to have pioneering surgery that will reduce the pain caused by spasticity in his legs and hopefully enable him to walk."
- More information on that here
Tommy Evans

Tommy Evans winning a stage of the FBD Insurance Rás in 2000.
Major cycling achievements: Irish national road race champion and FBD Insurance Rás winner, five-time national time-trial medallist.
Marathon PB: 3:03, Dublin 2013
How was it?: “It's a real mind game. Getting to 20 miles feels easy but then everything falls apart; your legs feel like you have been hit with a meat cleaver.
“I have unfinished business but next year all being well I’ll be in the sub 3-hour club.”
Derry McVeigh

The former Irish team manager was a powerhouse against the clock and set some blistering times over 25 and 50 miles....as well as 26 miles on foot..
Major cycling achievements: Jim McQuaid Memorial, Cyclewways Cup, Tour of Armagh, John Beggs Memorial, National team time-trial, Tommy Givan Memorial.
Marathon PB: 2.58, Berlin, September 2015
Barry Monaghan, Newry Wheelers

Monaghan still rides the bike but more for fun now as work and family time determine.
Major cycling achievements: Ulster team in FBD Insurance Rás (with Tommy Evans, David McCann, Paul Giles and Denis Easton), 9th on Stage 7 of 2009 Rás (when Sam Bennett won), multiple domestic wins.
Marathon PB: 2:44, New York, November 2010
How was it?: “New York is very hard and hilly. I always ran in winter for conditioning but when I finished racing at international level in 1996 I took up running fairly seriously, particularly cross country.
“I was NACAI senior cross country champion in 1997, but after that spent a lot of years with injury.
“For all the big races I rode in this country and abroad, I still consider the marathon as the ultimate 1 day challenge.”
- Other notable mentions are; Former national vets champion Anthony O’Brien (Fermoy CC), 2.53, Dublin 2014; Former Irish international Paddy Moriarty, 2.52; Former Gorey Three-Day winner Ken Norgrove, Dublin Wheelers, 2.32.