Photo: RankinIf you watched a 69-year-old Mick Jagger bring down Madison Square Garden at Wednesday night's 12.12.12 – The Concert for Sandy Relief in New York, then you were reminded that The Rolling Stones is one band that defies its age and its wild past.

And for those eager to write off that energy as a two-song fluke, Mick invites them to order up Saturday night's worldwide pay-per-view presentation of One More Shot, the finale of their golden anniversary mini-tour, which starts at 9 p.m. ET.

If the first four shows in London and the New York City area are any indication, Jagger will spend nearly two-and-a-half hours roaming a giant lips-and-tongue stage while Keith Richards, turning 69 next week, lays down his collection of Hall of Fame riffs and 71-year-old Charlie Watts hammers away at the kit.

"How do you do it?" ABC News asked Jagger, pointing out that if the Baby Boomers in the audience are willing to pay $700 for a ticket, imagine what they'd pay for his magic elixir or workout regimen.

"I don't really have much of a fitness regimen to be honest," he said to Nightline in an interview that aired Thursday night.  "It's pretty low-key.  I mean, I do have one, but it's not horrendously awful or long or difficult.

"Just what I do, really," Jagger continued.  "And then after that, you have a room full of people come over and go crazy and drink all your wine."

Speaking of wine, this tour is an admitted test of willpower for guitarist Ronnie Wood, now sober for three years.

"Yeah, we hit them with clarity and focus now," Wood said.  "Before it was eyes down and meet you at the end, you know?  And, 'Oh no, how am I going to get out of this?' A little bit of that still goes on."

Long past his notorious battles with heroin, Richards still enjoys a drink or three.  But more startling than his survival is the band's willingness to work together after his 2011 autobiography Life.   The book spilled a fountain of bad blood, painting Jagger as a megalomaniac willing to put personal business before the band, and the brutally honest revelations cast serious doubt that the two could come back together in time for the 50th anniversary.

"There was a time when I thought it wasn't going to happen," Wood said.  But Richards reportedly apologized to Jagger, and tells Nightline their relationship these days is "great."

"We're made to do this," he said.  "It's when we're not working that it's a problem."

"People say, 'Well, why are you still together?'" Jagger said.  "And I say, 'Well, because people like us.  If people didn't like us, I'm sure we wouldn't be playing.'  Of course, we love playing because we love playing music together.  But you have to have both of the part of the equation."

Copyright 2012 ABC News Radio