The logical foundation of strength training is that we build muscle by lifting heavy weights. It’s an adaptation of the body similar to developing darker skin as an adaptation to intense sunshine. We call that adaptation a suntan. Stand in the shade and your tan does not get any darker. Lift an easy weight and your muscles don’t get any stronger. Makes perfect sense.
So if you want today’s workout to build some new muscle you will need to lift a heavier weight than you usually do. A heavier weight than the last time you lifted. Or maybe if you lifted a weight for three reps last time you need to do four reps today. Something more intense. Something akin to brighter sunshine.
If your last workout was truly productive it stimulated some new muscle growth. If you waited enough time for that muscle to grow (like you have to wait for hair and fingernails to grow) then you should be stronger today. So when you return to the gym you should be able to lift a heavier weight or at least generate higher intensity (total weight / time).
Your last workout is inferior now. It’s like standing in the shade. You need more intensity today because you are a stronger person than you were during last workout. You are a new man.
No Two Workouts The Same
If every workout you perform is productive (and is there any reason it should not be?) then it causes new muscle to grow. If you have new muscle you are stronger. If you are stronger you should lift heavier weights more times. If you are doing everything right then every workout should be different than the last one. No two workouts should deliver the same intensity to a target muscle.
Of course, it’s impossible to know if today’s workout is more intense than the last one if you don’t take some basic measurement.
The fact is the first example is better by about 5% in terms of both momentary intensity and sustained intensity. This is something you can’t just “feel.” To know these facts you have to measure things.
The reason so much crappy advice gets circulated year after year in gyms, magazines and blogs about strength training is because nobody measures anything in the gym. So nobody gets proved wrong. Measurement cuts through the opinions and gets down to facts. What exercises deliver the most intensity to the triceps? What combination of weight and reps delivers more intensity?
When you measure you suddenly have facts instead of lore and opinion.
When you measure you can pre-engineer productive workouts.
When you measure you can become a new man.