Start in standing position. Bring up your knee and when you reach the top, kick out your leg. Hop to your other leg with the same motion.

Low Impact: Instead of hopping from one leg to the other, place your foot back down and then bring up the other leg.

Start in plank position. Then quickly drive your right knee towards your chest, making sure your foot is not touching the ground. Replace your leg and quickly switch to the other leg.

Low Impact: Same motion as above, but return to plank before repeating the motion with the other leg.

Think of this as a 'football shuffle' moving left to right, about the length of a yoga mat. Do this at a medium to quick pace.

Low Impact: Slow down the pace

Essentially running in place but drive your knee higher than your waist or as high as you can.

Low Impact: Quickly drive the knee up and replace the leg back down firmly before switching to the other leg.

Just normal jog in place. If you are on your last set; pick up the pace a bit and for the last few seconds, sprint like you are finishing a race.

Low Impact: Keep your feet close to the ground and move at a slower pace.