Mötley Crüe bassist and co-founder Nikki Sixx believes health and fitness are an integral part of being a performing artist. Rockers who don't prioritize their fitness are taking their position for granted.

Sixx tells Fresh N' Lean in a recent Instagram Live conversation that he has battled a naturally heavy physique for his entire life. Slimming down and making time to train in the gym has long been part of his pre-tour ritual.

"My family is naturally, a lot of them, overweight. I'm 195 pounds, 6-1. When I go into full cardio and light, medium weight, I'll go down to about 185 but actually put a little bit of weight on. So I have to work really hard. My body wants to go 200 — it wants to do that. And it's not necessarily for vanity reasons — I just don't operate well [at a heavier weight]; the machinery doesn't operate well; I don't think good; I don't sleep good. So health and exercise has become such a part of my life."

Sixx continued, noting that his health-conscious mindset began, ironically, while he was still abusing drugs and alcohol.

"I think back, even around Shout at the Devil, I was drinking a lot of whisky back then, but I remember trying to get into sort of workout, training things to get ready for the tour," he continued. "'Cause it takes it out of you onstage. People come from everywhere to come see you play, and you just stand up there all tired with a beer belly. I mean, that's irresponsible. There's a million other bands that would like to have your job."

Check out the full conversation via the player below.

The bassist's comments come as Crüe frontman Vince Neil has been under immense scrutiny for his own physique. Neil has publicly struggled with his weight over the years and drew criticism this past spring for appearing winded during numerous solo performances.

Fans pointed out that Neil was supposed to have gotten back in shape more than a year ago, ahead of the Mötley Crüe's originally scheduled 'Stadium Tour' with Def Leppard.

Later this summer, Neil revealed that he had been "trying it all" to slim down ahead of the tour, including cutting edge electromagnetic fat loss treatments.

Neil had a setback a couple of weeks ago, however, when he fell off the stage in Tennessee and broke multiple ribs. The singer is reportedly recovering at home, but there is no timetable for when he will be back onstage or in the gym.