I have a set of weights in my home office. Whenever I lose concentration or need a break (or feel a bit twitchy), I do a few weightlifting exercises (usually no

I have a set of weights in my home office. Whenever I lose concentration or need a break (or feel a bit twitchy), I do a few weightlifting exercises (usually no more than 20 reps at a time, but several times a day). This has helped me a great deal in becoming fitter and instead of being a tedious chore at the end of the day, exercising is now a welcome break that clears my head. However, long before I started doing that, I discovered the best way to stop myself from suffering back pains and RSI: Drinking tea. This works exceptionally well because it means getting up and walking around every 30-60 minutes to get a fresh cup, which is all it took to interrupt whatever cramped position my back and arms were in (the tea itself doesn't matter, although I recently switched to a decaffeinated type). As additional benefit, during either type of break I often have new ideas about the work I'm doing.