First, I'll second the folks who have already responded by saying that you shouldn't be typing for 15 hours per day. Coding, perhaps, but easily 1/2 or 2/3 of t

First, I'll second the folks who have already responded by saying that you shouldn't be typing for 15 hours per day. Coding, perhaps, but easily 1/2 or 2/3 of the time you spend programming should be spent thinking, reading code, etc. If you're consistently banging out line after line of new code for >12 hours per day, something is horribly wrong with your workflow, and I can't imagine you're getting much of an opportunity to refactor and test your code as you go. That being said, I've found that even 8-10 hours of steady typing can be too much for me, unless I'm using an ergonomic keyboard and good office furniture. If you can find any model of keyboard at all that works for you, buy it. Ditto for wrist rests, chairs, monitors, whatever. If it's expensive, make your employer pay for it. No manager worth their salt should look askance at spending $1-2k if it'll keep you in front of the keyboard for even an hour longer per day. If you're working for yourself and therefore self-imposing these ridiculous hours and spending limits, then stop. Seriously, just stop. Think about whether the payoff is going to be big enough to make crippling yourself for life. Hell, if you're really sitting at a computer for 15 hours a day, you're probably at risk of getting blood clots in your legs from lack of motion. No startup is worth dying over, or even seriously degrading your quality of living in the future.