"I think I've always had the speed but I have not really been able to keep it going.
"I think that motocross is as much a mental sport as a physical one and when your energy is sapped, that's when you make mistakes and crash.
"You feel discouraged when things don't work out. When you're fit and strong, it's all good."
Elwin led Saturday's first two races from start to finish but she had her work cut out in race three.
"It was pretty nerve-racking. [Tauranga Yamaha ace] Casey Waterhouse was pushing me all the way.
"She was in front for the first lap and a half, until I managed to jump past her and take the lead. But she stayed with me until the end."
Elwin will be back to compete at the Acerbis Four-Hour race at Taupo next weekend.
She will join forces with fellow Taihape rider Josh Anderson (Yamaha YZ450F) and the pair will tag-team for the event.
"I finished runner-up in the mixed teams' class at the Acerbis event last year, but it would be nice to win it. I'm definitely going for the No1 spot."