I've been interestest in fitness for a while, and Crossfit is the most effective program I have ever tried by far. It is designed specifically to boost your cardio endurance, stamina, strength, flexibility, power, speed, coordination, agility, balance, and accuracy. The workouts are challenging and fun (they whoop your butt!), are completely different each day, and are making me fitter every week. It's not for everyone, but give it a try. I think the first class is free...
