I agree strength training is life changing, but it can aggravate some RSIs. My RSI was similar to tennis elbow and it was from irritating the nerves in elbow from movement. The only solution is to stop flexing the elbow (rest). I fixed it by using 1) trackball mouse, 2) keyboard without num pad (less movement to get to mouse), 3) vim text editor and excel without mouse.
I had exactly the same problem. Heavy tendinitis in my right elbow, mostly due to a regimen of squash, badminton, and rock climbing multiple times per week.
I similarly switched to trackball mouse and keyboard without num pad (I was already on vim).
But what helped me more than anything was a keyboard tray that goes below the desk, almost on your lap.
Whenever we move offices at work, it sometimes takes a day or two before the tray is installed and I notice that the discomfort starts coming back quickly.
I had a very similar experience. I stick to a 10 keyless keyboard (no numpad) but I gave up on the trackball. I use a wireless trackpad now because I ended up with pains in my thumb after a couple years of the trackball. I could probably have used a better quality trackball but the selection is/was limited.
vim support in IntelliJ is pretty good these days so that's a huge help too. I had to abandon emacs and my claw movements early in life...
