Thirty-four years into his career as Metallica’s lead guitarist, Kirk Hammett’s routine around this time remains the same. Tour is about to start, so it’s time to run.

“It’s important for me to be in shape, and make sure my cardio is up,” Hammett said on the phone recently from his San Francisco home. “Running around on stage for two hours or so with a 10-, 15-pound guitar, you know, it’s taxing.”

All older than 50 now, Metallica’s members are more mindful of the physical toll that comes with a four-month tour (which kicks off Wednesday at M&T Bank Stadium). But musically, the California-based metal quartet nearly sounds three decades younger, again playing with the fast intensity and relentless brawn that made their mid-’80s albums vital documents of the American metal scene.

Fans seem to like what they’re hearing. “Hardwired … to Self-Destruct,” the band’s 10th studio album, entered Billboard’s album chart at No. 1 in November with the third-highest debut of the year, and sales for this tour have been strong, the guitarist said.

“It looks like we’re selling more tickets than we have ever before in the United States,” Hammett said. “Knowing that has made everyone super excited about the tour. It’s a good place to be because we feel pretty fresh.”

It’s an expected answer during a promotional interview, yet also an astounding claim, given Metallica’s tumultuous and highly successful journey to today. From genre-defining records and nine Grammys to lineup shakeups and epic infighting, the Rock and Roll Hall of Fame inductees have experienced “incredible highs and incredible lows,” Hammett said.

Even he’s surprised — years after Metallica’s becoming one of the biggest hard-rock acts ever, with more than 100 million records sold.

“It amazes me that we’re still together. We’re a band that is just as volatile as any other band, maybe even more so,” he said. “The reason why we’re still together is because we have a mutual respect for what we have done in the past, and we have a respect for what’s going on now.”

Hammett’s enthusiasm for “Hardwired” reinforces his reasoning.

Some listeners have criticized recent Metallica albums — like 2003’s “St. Anger” and the 2008 follow-up, “Death Magnetic” — for distorted sound quality, tinny drum sounds and other questionable production choices.

While Hammett stands by those albums, he also acknowledges “Hardwired” simply sounds better to his ears. He credits producer Greg Fidelman, and the fact this was the first album Metallica recorded entirely at HQ, their recording-studio complex in San Rafael, Calif.

“I personally think it’s a lot easier to listen to than ‘Death Magnetic,’?” Hammett said. “It’s kind of obvious, but I really feel like this is the best drum sound we’ve had in the last 10 years.”

“Hardwired” has received mostly positive reviews, which hasn’t always been the case in recent years. “St. Anger,” devoid of guitar solos, and “Lulu,” 2011’s collaborative album with Lou Reed, were polarizing records for fans and critics. Hammett said he has learned to be proud of the work, regardless of the reception.

“I know I can go to bed at night knowing I worked my hardest,” he said. “That in itself makes it somewhat bulletproof in my mind, knowing that we did the best we possibly could do.”

That same mindset extends to Hammett’s approach to touring. Metallica is “hungry about the future,” but they also keep touring because “I don’t think we’re done playing music for the fans,” Hammett said.

With big-budget, is-it-live-or-is-it-not pop spectacles dominating the road, he believes it’s more important than ever to deliver an authentic, “completely analog” performance. (Fans can watch the preparation, as Metallica will live-stream their Baltimore rehearsal at 9 p.m. Tuesday on the band’s Facebook page and website.)

“I think people are hungrier for that more than ever, whether they realize it or not. I think it’s our duty and our obligation to hold that up, and not give in to some technology that replaces us,” he said. “It’s important we show up.”

wesley.case@baltsun.com

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