Here are a few things that I have found to be useful and am happy to recommend to others:
Spending hours every day hunched over a laptop is a terrible idea (as your back and neck will eventually let you know). You can improve things by using a laptop stand, coupled with an ergonomic keyboard and mouse. My current setup includes the Nexstand Laptop Stand and the Microsoft Sculpt Ergonomic Desktop.
What “proper running technique” means is a highly contested matter. I have had good results (no injuries or pain) by following the ideas of ChiRunning and using running shoes with thin, flat soles (no inclination from heel to toe).
Chances are you have been taught how to swim the wrong way. You probably think that speed depends on chopping the water furiously, pushing hard with your hands and kicking fast. If you read and apply Total Immersion you will discover there is a smarter way: you can learn how to glide effortlessly and you actually enjoy the experience of swimming.