Begin by standing on a comfortable surface where you have plenty of room at each side.

With a 5-lb. potato sack in each hand, extend your arms straight out from your sides, and hold them there as long
as you can. Try to reach a full minute, and then relax.

Each day you'll find that you can hold this position for just a bit longer.

After a couple weeks, move up to 10-lb. potato sacks.

Then try 50-lb. potato sacks. Then eventually try to get to where you can lift a 100-lb. potato sack in each hand, and hold your arms straight for more than a full minute.

After you feel confident at that level, put a potato in each of the sacks.