3 Shortcuts to Strength
From ChangeOne.com

Some strength trainers are destined to become enthusiasts. But you may not be among them. If exercise seems grueling or dull, look for ways to make your hard-won efforts more effective and keep your workouts interesting. Here are three ways to start:
1. Gang up on muscles. You'll see the biggest overall strength gains from what are called compound exercises, which hit large-muscle groups across more than one joint in major areas such as the thighs and chest rather than isolated muscles. For example, doing a push-up (or a modified version of one) will strengthen multiple chest, shoulder, and arm muscles, while a dumbbell fly isolates the chest's pectoral muscles.
2. Mix it up. Eventually, any exercise reaches a plateau -- a point of diminishing returns when continuing to do it no longer produces substantial gains. To keep challenging muscles (and stave off boredom), change your exercises or routine periodically. One simple change: Jazz up a cardio workout by breaking in with periodic strength exercises. Example: In many cities, pedestrian paths and parks are scattered with exercise stations that allow intervals of walking to be punctuated by simple exercises such as stomach crunches or step-ups.
3. Suck in your gut. A hot topic in the fitness field these days is the value of building muscles at the body's core -- the torso. Sophisticated training methods such as Pilates, which requires trainers and special equipment, have sprung up as a result, but the idea that a strong torso stabilizes the entire body isn't new. Nor are exercises to do it. One easy method: Make the most of your walks -- even casual strolls through parking lots or malls -- by toughening your torso while you amble. To do it, draw your abdominal muscles in as far as you can and hold for five seconds while breathing normally. Let your gut out and repeat. It's like doing crunches on the run.