Embarrassing, but theoretically exercise ...

[NotQuiteCockney]

No, it's not a sex thing - it's (imo), worse.

I have a hobby that involves rapid repeated movement. My right arm, in particular, is suffering very badly. Whenever I try to drum Suffragette City on hard do this particular activity lately, after a few moments, the muscle just hurts. A lot.

Do I just keep doing the same thing every day, and figure the muscle will build up? I've been doing it for a week maybe now, and I don't feel any improvement. And now my arm aches even when I'm not drumming doing it.

[NotQuiteCockney]

Bump?

My shoulder is starting to hurt on that side, too ... grr ...

[Littlefish]

Sounds to me like you need to give it a rest for a few days.