If you want to burn 100 calories in 10 minutes, and tone your bum and legs at the same time, go for a run. For even greater lower-body-sculpting power, you'll need to add hills to your workout.
I know. I know. Hills are horrible! And if running up hills is way too challenging, walking briskly will do the same magic. This interval workout combines walking hills and short sprints with just a bit of incline to reduce the chance of developing shin splints. Aside from a toned bum and thighs, intervals are also proven to target belly fat, so it's doubly effective. In about 40 minutes, you'll burn over 400 calories!
Set the treadmill incline to one, and get started! For each three-minute brisk walking interval, you'll need to raise the incline to 15 percent (or as high as it'll go), and for each 60-second sprinting interval, you'll need to lower it to one. Adjust the speed as necessary if either the walking or sprinting pace seems too slow or fast.
Total calories burned: 416
*Calories burned calculations are based on a 130-pound woman
Click here for an image-free, printable version of this workout to take with you to the gym.