An exercise for people who are out of shape: Begin with a five-pound potato bag in each hand. Extend your arms straight out from your sides, hold them there for a full minute, and then relax. After a few weeks, move up to ten-pound potato bags. Then try 50-pound potato bags, and eventually try to get to where you can lift a 100-pound potato bag in each hand and hold your arms straight for more than a full minute. Once you feel confident at that level, put a potato in each bag.