One of the best ways to stay motivated is to train with a friend under the guidance of a functional training expert. Ideally, you and your friend would be at the same general fitness level to start. For example, both beginners, or intermediate, etc. Each hour session starts out with a gradual warm-up, with the better part of the session involving sustained but modulated, engaging and challenging, full-body, multi-joint functional exercises that boost metabolism, employ and prime all three energy systems, and sets in motion some serious gains over 10 weeks in strength, endurance, power, coordination and finesse.  Partner training makes economic sense as well: twice the fun at less than the regular personal training rate.