Motley Crue’s Stadium Tour with Def Leppard, Poison and Joan Jett is set to take place in the summer of 2022, and Nikki Sixx has stressed the importance of being in good physical shape for such a large endeavor.”When you play a two hour show in a stadium, it’s a 90-foot span from side to side,” Sixx described to Loudwire Nights host Toni Gonzalez. “So when you’re playing in a stadium, you’ve got all that room —…