Effective strength training is based on a principle called progressive resistance.
The resistance (the amount of weight you lift) slowly increases (progresses) over weeks and months.
A simple concept, but to carry out progressive resistance and make it work requires a degree of self discipline.
At our advanced age, self discipline is a quality we are supposed to have in abundance, so I guess we're in luck.
Progressive resistance offers two main benefits: First, it lessens the chance of injury, which is particularly important for those strength trainers who are 50 and over.
Second, progressive resistance keeps challenging your muscles, making them work just a bit harder whenever you bump up the amount of weight.
Over several months, that can result in some impressive gains in strength.
If you're new to strength training, it is best to start with minimal weight, and slowly add small amounts of weight over several weeks and months.
For example, for a particular exercise you might add 2-1/2 or five pounds every week or two if you feel your muscles have adapted to the old weight.
To minimize muscle soreness and chance of injury, here is a good rule to follow: with any new exercise movement, your first workout session should be with minimal weight.
If you are using a bar, that means no extra weights on the bar.
With dumbbells, choose one of the lightest sets.
With a machine, you would the set at perhaps 10 or 20 pounds.
The second time that you perform an exercise you should increase the weight to a level that offers noticeable resistance, but does not make you strain whatsoever at the end of a set.
This would be about 50% of the weight you think you'll end up at once you start going full steam.
On your third time with a particular exercise, try to bump up the weight by 5 pounds or so.
Increase the weight by 5 pounds (or less) each session until you reach the point where the last repetition is difficult to do.
However, you should be able to complete that last repetition without losing proper form and without excessive straining.
If you add too much weight and you can't finish your planned repetitions in each set, take off a little weight the next time.
Every week or so, re-evaluate your progress and how much weight you need.
Add a little weight if you think your exercise is too easy.
One reason we start with minimal weight is to prevent the soreness we talked about.
You may still experience some soreness, but believe me, it won't be nearly as bad as it would be if you started with heavier weights.
The other reason is so that you become accustomed to the proper motion before you add lots of weight, which minimizes the chance of injury.
You'll find in the early going that you can add weight pretty often, as often as once a week.
As the weeks and months pass by, you won't be able to add weight as frequently and eventually you'll go for months without adding weight.
But always keep trying to make progress, and never fall into the trap of being satisfied with the same old weight.