Now that we've gotten past all the showers (at least in the Northern Hemisphere) and are in for a long stretch of sunlight and warm weather, let's make our challenges more appropriate.
1. The 100 Mile Diet. If you haven't read the original book, please check it out here. Stick to your Farmers Markets and draw out on a map what towns border your 100 mile radius. Keep the food local and shake the hand that fed you. You'll really start to develop an appreication for what food is grown in your area and the distances that some of your favourite fruits and veggies have to travel so you can have them all winter.
2. Grease the Groove. If you haven't read my original article, Greasing the Groove, please do so now. This method will help you get stronger in a short amount of time. Choose a couple exercises and do them every 2 hours while you are awake. Pushups, squats and pullups are the most appropriate. You'll learn that your nervous systems gets super primed and better able to cause your muscles to fire more forcefully and at any time. This is a great way of increasing your max pullups or pushups by a number of repetitions in only a couple of weeks.
3. Daily sketching. I know this is not directly related to fitness, but drawing will help stimulate the creative portions of your brain. If you keep all parts of your brain firing off electrical impulses, you'll perform better in any activity.
Check out this RSA Animate video on motivation.