At the end, after being helped off his bike, Eugene Collins sat down on a hard plastic seat next to his family with a big sigh of relief.

Twenty-four hours, 725.75 kilometres and 2903 laps after starting his New Zealand indoor record at the Stadium Southland velodrome on Saturday, Collins was just pleased it was all over.

"Relief at just getting through it. It would have sucked to have done all this and not made it," Collins said when asked what emotions he was feeling after breaking the previous mark of 660.9km set by Colin Anderson in 2008.

It almost didn't happen.

Mindful that he needed to maintain his nutrition, he ate too much during the first few hours after his noon start on Friday and his stomach tried to rebel.

He seriously considered stopping, not because he wanted to, but because he didn't think he'd be able to carry on.

One of his minders, New Zealand outdoor record holder Stu Downs rang the supplements company and asked their advice and they suggested taking all his food away for an hour to see what effect it had.

After a time Collins started to feel better, but when he passed Anderson's mark at 9.42am on Saturday it took all the mental strength he could muster to keep riding for the final two hours.

In the 24 hours after his first son, Harrison, was born, the baby underwent four operations and an emergency flight from Wellington to Auckland where he was put on a heart/lung bypass machine.

Some days are harder than others.

Now a happy, healthy child, Harrison, 9, and his siblings Pierce, 8, and Lauryn, 7, were there with mum Fiona to watch as Dad achieved something special on Saturday.

Money raised from the successful record attempt will go towards the Ride4Life charity programme which provides funds for the Neonatal Trust, an organisation which is obviously close the Collinses' hearts.

"Gutsy! He's just blown me away," proud wife Fiona said at the finish.

Collins thanked the more than 20-strong support crew he had in Invercargill, including many who remained at the velodrome for the entire 24 hours.

"Without you I wouldn't have been able to get through those last two hours," he said.

"I'm never, ever, ever riding on a track again. The bike is for sale."

Fiona said she was looking forward to having her husband back again - "until he comes up with another crazy idea", she said.

The Ride4Life 2013 charity drive has raised more than $50,000. A final figure may not be known until next week.