This is a very physically demanding advanced table tennis exercise that will improve your general table footwork and fitness. Start the exercise by hitting the ball around 60-70% of your capable speed to ensure that you are able to make a minimum of 6-8 successful forehand topspins. When you get your footwork into rythem you can then increase the speed accordingly.
Though TTFit set out exercises for you to try, they are mostly there for inspiration - feel free to deviate and adjust to suit your game better. The most important this is that you give it your best... always.