I read a lot of fitness magazines. Near the holidays, most featured quick workouts for when time's tight. These are my top picks. I do them either for a second workout in the evening, in lieu of my regular workout if I'm short on time, or before strength training. Note that you should do at least five minutes warm-up (light cardio: walking or jogging in place, step, jumping jacks, or just dancing around) before any workout and five minutes stretching afterwards to prevent injury.
1. Total Body Recharge: Energy-Boosting, Muscle-Burning Workout from Fitness Magazine
Video | Slideshow
This takes about 20 minutes, requires no equipment, and really does boost your energy. You can do it anywhere, even in a hotel room while traveling. Image from one of the exercises at right.
2. Crush More Calories: 15-Minute Workout from Women's Health Magazine
This is the best, quick workout for a serious shot of cardio. The moves also sculpt, so your muscles work hard while you blast fat.
3. 10-Minute Sculpting Blast from Shape Magazine
This is a really good, quick cardio workout, and you only need a weighted ball (or dumbbell). I don't use a jump rope--just my hands.
4. Your Do Anywhere Workout from Shape Magazine
Circuit 1: Melt Fat Fast | Circuit 2: Firm & Burn | Circuit 3: Total Body Sculpt
This workout features three five-minute circuits. You can do them all at once, or break them up if you really only have five minutes to spare.
5. Two-Minute Sexy Arm Exercise from Shape Magazine
This exercise actually works your back, biceps, shoulders, abs, and legs. If you have time for only one strength training move, this should be it.