Greek gymnasia. Burmese monasteries. The Italian parliament. Every culture has a sacred male space, where men will be boys. For modern Brits, that space is the Dave channel. Dave's your mate, the marketing tells us. You do five-a-side and pub quizzes together. The only problem is you have to share the winnings with his 27 million other mates.

In a crowded digital market characterised by fragmentary audience share, Dave is an outlier. While total TV viewing in the UK is down across all other networks, Dave is growing. The biggest channel outside of the public broadcasters, Dave is celebrating its strongest quarter yet and is watched by more than half the men in the UK. Are they boneheads? What's going on?

To get to the bottom of the mystery, I'm standing at the top of Wank mountain. Alongside me in the Bavarian Alps are Olympic long-jump hero Greg Rutherford and comedian Josh Widdicombe. We are here as part of Dave's new travelogue, 24 Hours To Go Broke, a show in which sportsmen and comedians try to spend £10,000 in one day in uncommercial locations such as post-communist Armenia, or Cork. I know, but Countdown doesn't make any sense either, when you really think about it.

From Wank's snowy summit, suave Olympian Greg looks like James Bond in The Spy Who Loved Me. Josh resembles Samwise Gamgee surveying the prospects of Mordor and deciding they don't look good. The crew are spending an interminable amount of time doing something crew-y. So far today the pair have bought some chocolates and visited a museum where they watched a 40-minute video about bobsled fatalities. Widdicombe describes the latter exercise as "a total waste of time", especially it was free to enter.

"Why don't we rent as many library books as possible?" Greg suggests.

"You only pay when they're late," Josh replies.

Wandering about, I find Greg on his own and try my hand at lad-speak. Dave is, after all, the home of "witty banter" (as if witty banter were formerly a feral cat looking to come indoors) and this must be the reason for its success. So is Josh a twat, or what?

"Laughter is such an interesting emotional response to demand from people," Greg reflects, un-laddily. "That's what makes a comedian like Josh so powerful, even though he comes in a small package."

I don't want to get into Josh's small package, I say, which is first-rate banter, but Greg isn't interested. "What do you think of sportspeople?" he asks me. Confident, dumb, lovable? He nods. "I have a lot of frustrated creativity," he says. "I take design seriously. I love history, particularly the medieval period, right through to the late Tudors."

I had wanted some salty anecdotes about the Olympic Village but this doesn't seem like the right time to ask.

"When you do sport, people assume you're an idiot," he explains. "A couple of people give the rest a bad name. Like Joey Barton, who's just a bellend."

Greg seems a bit sensitive to be a lad. Which might just make him ideal for Dave. Its success may partly be driven by repeats of shows such as Top Gear – a stud-pasture for Ukip sympathisers – and Storage Hunters, the US phenomenon in which grown men punch each other amid piles of rubbish like alcoholic Stig Of The Dumps. But while UKTV, which owns Dave, used to be almost entirely made of repeats, last year it ploughed a record £110m into programme investment. Commissions such as Dara O Briain: School Of Hard Sums, the archly conceptual Dave Gorman: Modern Life Is Goodish and a new series of Yes, Prime Minister on Gold indicate it's not just after numbskulls. Dave's no longer in the pub every night recycling the same old stories. He's taking evening classes.

Back on the mountain, the crew are ready. Time to make it rain. Josh picks his way over to a nearby family to pay for an ad-hoc German lesson in a cable car. The claustrophobic result, faltering into uncomfortable silence, is superbly awkward. Greg swoops off down the groomed slope to pay fellow skiers to tell him jokes. A crew member – hoisting a camera as cumbersome as a foal – follows. With no free hands for ski-poles, he's simply balanced on slats, hurtling at a frictionless 50mph. It's undeniably manly.

'Men won't watch "female" channels like Really but Dave's almost evenly split. Women are equally drawn in by comedy and will watch a male-branded channel. So it makes sense to brand male'

Within 10 minutes, a radio mic crackles. "He's dislocated his shoulder." Masculine displays are often the hirsute bedfellows of terrible accidents. The crew are now a cameraman down and the lads have spent about seven euros. Things aren't going to plan.

"When things go badly, I'm delighted," Josh tells me. "Because it always makes great TV." A ready-loaded dispenser of quips, puns, zingers and Dutch football trivia, Josh fits Dave so perfectly they may as well share coats. Does he consider himself a top lad?

"People think I'm laddy, but I'm solidly beta," he demurs. "I don't like my friends to be macho. Life's not a competition."

The production decamps to a beer hall in town. Boys in leather britches slap their thighs, robust women in aprons slap tankards on the table. Bavaria has the largest number of beer halls in Germany, and they are all, as Josh points out, like racist parodies of themselves. "It's like when Frasier does an episode in England and you think, 'That's genuinely offensive.'"

In a worrying turn, they've challenged the locals to a Pub Olympics. There are bets, arm wrestling, competitive drinking. Money is handed out like Bonios at Crufts. I worry someone will make me pull their finger or do a Jäger bomb, but no one does.

Some of Dave's manshows are macho: anything to do with monster trucks, or Trawlermen, in which rough-hewn Scots harvest an avalanche of prawns off the North Sea. But these programmes, which ape a rugged US model, are the exceptions. Instead, Dave's preferred strategy is to cover everything in irony. Banter – which hurdles the sappiness of upfront emotional bonding – is our national hobby. Telling a friend, 'Your face looks like it caught fire and someone tried to put it out with a fork' is a fairly oblique way of saying 'I like you', but it's how we prefer it. Dave's great success is packaging it. There's another little secret about macho-bloke channel Dave. Not only is it not that macho, it's not that bloke. In what we'll call a reverse Crying Game twist, a member of the Dave team reveals that 42% of Dave viewers have tits. (She doesn't phrase it exactly like this.)

"Men won't watch 'female' channels like Really," she whispers, "But Dave's almost evenly split. Women are equally drawn in by comedy, and will watch a male-branded channel. So it makes sense to brand male." (This is how TV people talk.) So much for the gender agenda, or blokes' charter; behind every great man-channel stands an army of women, being sarcastic and farting.

After a few hours, the local youths are understandably weary of drinking creamy shots repeatedly for pickups. The crew are fatigued too, and have another day's filming ahead. Twenty-four hours to go broke? They've been broken in 12. "I can't drink any more," blurts Josh.

I leave the pub. Fairy lights string deserted streets, like the town that Christmas forgot. Over the road I see Greg in an antiques shop, looking at landscape paintings.

"If it moves you, you should buy it," series producer Simon is advising him.

Greg peers closer at the craggy peak in the picture: "Didn't we film up there?"

"Yes, yes, I believe we did," confirms Simon.

"Yes, that looks very much like Wank."

I laugh. It is pretty funny.

24 Hours To Go Broke airs in the UK on 13 May, 10pm, Dave