Plank Run

Here is another plank variation: Get in the plank position, with your back and hips aligned. Bend your knees as if running. For variation that works your oblique muscles more, bring your knee to the opposite hip bone when you bend each leg.

Do this for 10 to 20 seconds at a time with 5 to 10 seconds of rest in between, or whatever variation works for you for a length of time that is effective. You should get a burn but not be in pain.

Step for Glutes and Quadriceps

You may have seen personal trainers do this with clients at the gym. Hold a bar of five to ten pounds, according to what you can do, or free weights of two pounds or more straight over your head. Step up on a step or a black platform with your right foot. Bring your left foot to join your right foot. For added intensity, go up only on your right leg and extend your left leg straight back. For yet added intensity, squeeze your left leg up one more inch when you think you cannot raise it further. The higher the intensity, the more you will work your right quadriceps and left glutes. Repeat for two to four sets of ten repetitions, according to what you can do. Then switch legs and repeat. The intensity also increases by the height of the step.