New exercise routine:
Begin by standing on a comfortable surface, where you have plenty of room at each side.
With a 5-kg 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 of weeks, move up to 10-kg potato sacks.
Then try 25-kg potato sacks.
Eventually try to get to where you can lift a 50-kg potato sack in each hand and hold your arms straight for more than one full minute.
(I am at this level now.)
After you feel confident at that level you may move on to the next level of the exercise.
Put one small potato in each sack.