Grab a back pack,load a plate inside.Throw it on your back and climb hills! I started out with a 35lb and walked hills,up and down non-stop for an hour.Walk as fast as you can up the hill standing with good posture and knees slightly bent.Walk slow and controlled down.For a twist,walk backwards up the hill.Be ready to burn and sweat. DO NOT DO THIS ON THE SAME DAY AS SQUATS OR YOU WILL SUFFER!!!!!!!