Recently came across this exercise suggested for the over 30's, to build muscle strength in the arms and shoulders. It seems so easy, so I thought that I'd pass it on to some of my friends and family. The article suggested doing it three days a week.
1. Begin by standing on a comfortable surface, where you have plenty of room on each side. With a 2kg 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.
2. Each day, you'll find that you can hold this position for just a bit longer. After a couple of weeks, move up to 5kg potato sacks. Then 25kg potato sacks and then eventually try to get to where you can lift a 50kg potato sack in each hand and hold your arms straight for more than a full minute (I'm at this level).
3. After you feel confident at that level, put some potato's in each of the sacks.