Does all the heavy lifting interfere in any way with your "piano fingers"?
In fact there was one week where the light movements of piano practice seemed like a nice active recovery for the muscles around my strained elbow: felt like I had a restorative blood flow and less soreness in that arm when I stood up, than I had when I sat down. But mostly I notice no impact either way. The 5x5x5 workouts are not such that they leave me totally drained, arms trembling. Even when I had more volume per workout, in Jan/Feb with sets of 3x5, there wasn't any impact on touch & feel at the keyboard.
A tough lifting workout, or an intense Judo class, might leave me too wiped to practice at all
: I could feel too tired to walk into the other room where the piano is, or even to get my ass off the couch. I have fallen asleep after workouts. But if I do go in and sit down at the piano, I don't really notice any impact from lifting.
(Barring obvious things like mashing my finger re-racking a dumbbell, or the stupid injury I did to my hand on Mother's Day, etc.)
You might expect that after slinging a heavy load, meathead lifter would be all "HULK SMASH!" at the keyboard. I've noticed no such thing. Of course it's worth pointing out that I don't exactly have the refined skills & feathery touch of Liberace or Horowitz or whoever. I'm still a beginner. Maybe I'm always
pretty much "Hulk Smash" at the keyboard, so any weightlifting effect is muted. One thing I do notice, when I've done lifts that have a positive impact on my shoulder posture, like BTN Press or the Incline Bench Row, then I feel great when I sit down at the keyboard. I wiggle my shoulders and futz with my posture, just feeling my muscles move. But that's not the kind of thing you're asking about (I think).
Maybe an instrument like guitar? Which requires a particular grip on the neck and finger strength to press and hold the strings at the frets? If you've fried your grip with deads and pull-ups and suitcase carries, maybe that would fuck up your playing later that day? But piano doesn't require much finger strength
(at least not yet for me). It requires placement & accuracy and timing (tempo): but not strength/power.
I have been tempted to add some wrist curls, dorsal and ventral, to see if they have any effect on my finger dexterity. But that hasn't progressed past the "I wonder" stage.