Belfast man Stephen Scullion will be among the record 22,500 competitors in Sunday's Dublin Marathon only three weeks after participating over the distance at the World Championships.
Like many, Scullion suffered in Doha heat as his time of 2:21.31 - some seven minutes outside his personal best - left him in 43rd spot.
But less than a month later, the 30-year-old is back for more.
"What can I say? I love running and love racing even more," says Scullion.
Speaking on Twitter on Saturday morning, Scullion added: "Exciting day tomorrow. Big day for Dublin and another 26.2 miles for myself.
"Prepared for a world championships in Doha just three weeks ago and tomorrow I'll do it all over again."
Scullion aims to boost Olympic prospects
Scullion's decision to compete over the distance again so quickly will have been influenced by the IAAF's new dual Olympic Games qualifying system which effectively gives bonus points for athletes who race in their national championships, which the Dublin event doubles as.
Scullion's personal best of two hours, 14 minutes 34 seconds is three minutes and four seconds outside the IAAF's qualifying standard for Tokyo but the complicated new system includes a world rankings element in addition to the bonus points component.
Another Belfastman Kevin Seaward marked himself out as the leading Irish male contender for Tokyo selection after clocking 2:13.39 in Berlin four weeks ago - the fastest Irish marathon performance since 2002 - but his time remains two minutes and nine seconds outside the putative IAAF standard and he is not competing in Dublin.
Scullion is likely to face stiff domestic competition with 2016 Rio Olympian Mick Clohisey, defending the Irish title after finishing sixth last year, plus Sean Hehir, Sergiu Ciobanu, Hugh Armstrong and 2012 London Olympian Mark Kenneally.
Newcastle athlete Eoghan Totten will also hope for a strong performance while Clonliffe's David Flynn, who clocked 2:19.04 to finish 13th last year, could also contend.
However, the Irish hopefuls will face a stiff task in competing for overall victory with Ethiopian Asefa Bekele hoping for a repeat success after triumphing last year.
Big Ulster interest in women's race
Bekele's compatriot Mesera Dubiso is also defending her women's title, which like the men's race will see the winner picking up almost £10,500.
The Ethiopian athletes may also have their eyes on £8,600 bonuses which will go to the men's and women's winners if they produce faster times than 2:09 and 2:30.
The women's race will have strong Ulster interest with Rio Olympian Breege Connolly, Laura Graham, Gladys Ganiel, Ann-Marie McGlynn and Catherine Whoriskey all among the entries.
Connolly's 2:37.50 performance in Rotterdam puts her top of the 2019 Irish rankings but that is some eight minutes and 20 seconds shy of the IAAF's Tokyo standard.
Kilkeel athlete Graham won back to back Irish titles in Dublin in 2016 and 2017 but her career has been affected by Achilles and knee injuries over the past 18 months.
The 40th running of the Dublin event will get under way from Fitzwilliam Street Upper from 08:45 GMT.