Just came across this exercise suggested for seniors, to build muscle
strength in the arms and shoulders. It seems so easy, so I thought I'd
pass it on to some of my friends here:


The article suggested doing it three days a week. 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,
then relax. Each day, you'll find that you can hold this position for
just a bit longer.


After a couple of weeks, move up to 10-lb potato sacks. Then 50-lb
potato sacks. 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.

(I'm at this level.)

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