The most important thing for those with muscular builds (mesomorphs)…
Is staying loose!
As you change from body type to body type (and change between them you can), as a mesomorph you will need to consciously keep loose far more, something with other builds you took for granted.
Shake out limbs, stretch, relax… relaxation is in the head too.
Fast and loose drills and a calm mind.
That’s gonna be your most important training.
Stretch more big guy. A superior human isn’t immobile.
Persistence & Tenacity