When it comes to Fatigue how do your lips generally feel? Like is it around your mouth that feels fatigued in the way that your arms feel after a lifting for a while, or is it your actual lip that aches? [When i say ache I don't mean hurt] I say this mainly because when I'm tired it's usually where the mouthpiece has been that gets tired and feels warmer but also my corners start to "smile" more when playing higher to compensate. Is that bad or should it be your entire lips that "ache"? i can't remember anytime my chops have felt as previously described. Only the rare occasion where I feel lactic acid build. Hope le this makes sense!