Andy Buchanan is no longer running scared as the Australian aims to go even faster in his first race since breaking the national marathon record.
The Bendigo teacher sent shockwaves through Australian distance running in December, his 2:06:22 at the Valencia Marathon lowering rival Brett Robinson's mark by more than a minute.
Robinson had broken Robert de Castella's 36-year-old record two years earlier, the pair now engaged in a friendly duel that will spark again at Sunday's Marugame half marathon in Japan.
Buchanan, Robinson and compatriot Jack Rayner are set to race the London Marathon on April 27 before Buchanan competes at Tokyo's World Championships in September.
Buchanan averaged 2:59 minutes per kilometre in Valencia and hopes to better that cracking pace, albeit over half the distance, thanks to some new-found conviction in Japan this weekend.
In a throwaway line that many runners could relate to, Buchanan admitted checking his pace-per-kilometre during a run "freaked him out".
"In Valencia I spent a long part of the race doubting myself," Buchanan told AAP on race eve.
"Thinking, 'What am I doing? Why am I running this fast?' (I was) questioning if I could do it.
"Now I have that belief; I'm more confident and excited to do a few more half marathons.
"There's still more untapped potential there and over the marathon (distance), improvement it's going to come pretty easily through that self belief."
Buchanan and Robinson spent most of January training at altitude in Falls Creek, pushing each other to new heights.
"He's got me covered at the moment (in the half marathon), so I'm looking forward to going up against him," Buchanan said.
"We're good friends and I know now I want to beat him even more and he wants to beat me even more."
Australian Isobel Batt-Doyle will also race in Marugame after moving to third on the all-time Australian women's marathon list in Valencia.
