Coffey was not interested. He believed voters would be far more interested in watching a debate between the two on Maori land reforms than watching them grunt it out in an Iron Man.
That is doubtful, but it was nonetheless a wise move from Coffey.
Coffey insisted he wasn't chicken - he said he had run half marathons himself.
But Flavell is Parliament's Forrest Gump. Those who have spotted him on the treadmill at Parliament's gym have reported he runs and runs and runs at pace for weeks on end.
Campaigns require basic fitness. There are the soap box steps, walkabouts, hammering of hoardings, and sign-wavings. For the biceps there are the sod-turnings, handshakes, and ribbon cuttings.
But a high performance sports department appears to have taken over the running of this one. Even the policies have become competitive sports.
In immigration, Labour and NZ First have both proposed Immigrant Bullrush - the winner is the one who stops the most migrants getting over the border.
But so far the most extreme event in the Campaign Iron Man is the housing challenge (or crisis, if you're Labour).
This has turned into quite the hammers at dawn event. Parties are building houses left, right and centre. No vacant land is safe.
National's most recent pledge was the loaves and fishes miracle of redeveloping Auckland land that now holds 8300 state houses to build 34,000 houses, flats and apartments over ten years - a net increase of 25,900 homes.
Labour's pledge is to build 100,000 over 10 years -half of which will be in Auckland. It is not yet clear exactly where these will be built - but it may be safe to assume it is on the same land National plans to use.
Labour says all its 50,000 Auckland homes will be affordable - defined as less than $600,000.
In National's package, Adams has said between 20 and 50 per cent of the homes would be affordable -defined as less than $650,000. That is something between 4,200 and 17,000.
Labour's response to National's pledge was to congratulate it for its realisation there was a housing problem at all after years of denial - and its Road to Dannemora conversion on whether the Government should be a property developer for the private market.
That conversion was presumably led by the realisation National had to be seen to be doing something on housing rather than any new-found belief by Prime Minister Bill English that Housing NZ was the best property developer in town.
His predecessor John Key was the champion at backflips, but it was clearly too much for the novice English.
Major announcements usually feature the party leader, but this one was timed while English was on a plane fleeing the country for a week.
Things are now at the stage of National saying there is no way Labour can deliver its number of houses and National saying Labour cannot deliver on its number of houses.
Act has since outbid them all anyway.
Act has promised 500,000 houses in Auckland. Act leader David Seymour said it would not need bricks or mortar. It did not need land or money. All it needed was a pair of scissors to cut red tape.
Seymour even started off his big building programme himself, helping build a Habitat for Humanity house in Newmarket.
"ACT and Habitat for Humanity did more over the weekend to address the housing shortage than Labour and National combined," he boasted.
Auckland is saved!
Until it got to the fine print, which revealed the house that Act built in Newmarket was to be dispatched to Kaikohe.
