Shaw said he had been doing a lot of running during the winter to stay fit and that certainly helped him during the long race at the weekend.
He took part in the Giant 2W Gravity Enduro last month in Rotorua, during his first race back from injury, and proved he is nearly back to his best with the win on Saturday.
Shaw, 23, is primarily an enduro rider which mixes downhill and cross country mountain bike racing. He said he wasn't even planning on racing in Taupo until a few days before.
"Mum does the race every year and was looking for someone to do it with her," Shaw said.
"I wasn't actually going to do the race this year because I have changed my focus to enduro racing."
He said his mum ended up twisting his arm and getting him to enter days before the race.
"She even paid for my entry fee, so I'll be able to pay her back now that I won," he said with a laugh.
Taupo man Henry Jaine came second in the men's race about a minute back and Edwin Crossling third.
The winner in the women's 85km mountain bike race was Wellington's Samara Sheppard with a time of 4h 28m 18s. Second place was Taupo's Greta Donaldson with Amber Johnston from Rotorua third.
About 700 riders entered the mountain bike events at the Lake Taupo Cycle Challenge.