Stretching. Believe it or not, stretching out your muscles or working on flexability is an important aspect when it comes to fitness. Many people, myself included, forget that sometimes. I'm not talking about going out to join some yoga class or do any kinds of complicated movements. There is in fact, the basics.
What is it you do almost without realizing when you wake up? No, not when you get out of bed; I'm talking as soon as you open your eyes. You uncurl yourself from your sleep position, and stretch. You are waking up your body, and letting the blood flow thru. That ladies and gentlemen, is stretching, one of the important things you could do, and you don't even think about it.
Straight from the mayoclinic, "Better flexibility may improve your performance in physical activities or decrease your risk of injuries by helping your joints move through their full range of motion and enabling your muscles to work most effectively. Stretching also increases blood flow to the muscle."
Take it from someone like me, a fellow human and mammal, stretching is pretty darn stellar. Most mammals you could possibly think of also stretch. Even plants, believe it not. They grow and stretch toward the direction of sunlight. So get up, reach for the sky, touch you toes, and grow!