Age is the one thing that creeps up on everybody, and for Metallica's Lars Ulrich, he worries about Father Time taking a toll.

In an interview on CBC Radio show 'Q', Ulrich wondered out loud if he and rest of the band will be able to hammer out some of their faster songs as they age into their 60s and 70s.

"Whether we can do the 'Fight Fire's' and the 'Battery's' and the 'Master Of Puppets' and all that in our mid-60s and our early 70s remains to be seen," said Ulrich, who turns 53 on Boxing Day.

"And there's kind of a second part to that, which is that if… I mean, we may be able to still play them — do you know what I mean? — but whether we can bring the weight and whether we can bring the energy and whether we can bring the attitude that those songs deserve in our 60s to 70s, I have no idea," Ulrich continued. "Hopefully we'll have enough clarity to be able to tell if it's not working, to walk away from it graciously and respectfully. But right now we're fine, and we've played some of our best shows in the last couple of years, and I think there's still a bit left in the engine. But whether we can do it in our 70s… hopefully we'll get a chance to find out."

Drumming Takes a Physical Toll

Metallica fans will note that, over the years, Ulrich's drum kit has gotten smaller and smaller. When playing live, he certainly doesn't throw in all the drum fills from the recordings, instead focusing on keeping time.

Not many bands have 70-year-old drummers. Charlie Watts of the Rolling Stones comes to mind, and he's 75. Now Watts isn't pounding out 200 beats per minute, but you get the idea that a drummer must be physically in-shape to play.

In fact, part of the reason Rush retired from touring was because drummer Neal Peart suffers from chronic tendonitis and shoulder problems, making him unable to properly play the complex parts he wrote as a younger man.

Ulrich noted he wants Metallica to go on for as long as possible, but can't predict the future.

"When people ask me to look into the crystal ball into the future: 'What do you think? Are you still gonna be playing…?'" he said. "It's the great, big unanswered question. Mentally, creatively, spiritually, aesthetically, we'll go for another hundred years [and] we're fine. Physically, obviously, it's the big question.

When touring, Metallica employs a couple of physical therapists to keep the band going.

It's actually kind of pathetic. People come backstage [and ask], 'Where's the Jack Daniel's?' There's no Jack Daniel's. It's brown rice and nasty protein shakes and a couple of trainers that are stretching us and stitching us back together again after the show," said Ulrich. "But at least we're still playing, and at least we're still functioning, and at least it still has some of the weight that it used to. So, so far so good, so we'll see where it takes us."

One drummer who comes to mind that's still playing at a frenzy is Iron Maiden's Nicko McBrain, who is now 64 years old, and never misses a fill.

Only time will tell how long Ulrich can keep it going. You've gotta figure he's got at least another 10 years in him.