You should be lying down straight on the ground with your knees

[Eliand 34]

in a locking position.Alpha Shred Let your arms to bear the full load of your body movement up and down. While coming down, your chest should almost brush against the floor. Remember to keep your arms extended straight in opposite directions when you raise yourself up. Walking is the most sophisticated exercise whose default mode is set by the Mother Nature to build your body muscles in legs. Do regular walking since it involves the larger body muscles of your legs to carryout work and remain active and healthy.

http://www.strongmenmuscle.com/alpha-shred/