Valdez said:
Intensity is literally defined as a % of your 1 rep max in weight.
When people say increase the intensity they mean, go to actual failure, or go beyond failure, or superset, or grow some fu&*ing balls and stop lifting like a woman.
for traditionalists yes
if you dont stray from a particular exercise, with the same variables. ie flat bench with a straight bar. the 1rm is basically all you can do.
by varying the exercise platform, balance, weight medium, etc though, one can acheive the same intensity level with less weight. still working the same motion but in a different manner. those are intensity builders.
example. if i were to have someone perfect a 1 arm dbell row. they get to where a 1rm max with perfect form is 90lbs. awesome work. how do i overcome that plateau? vary the reps with a lighter weight? continue to try to increase reps? sure....
now how about we change the bench that the person uses out for a stablity ball an make that person stand instead. its still a dbell row right? but now the person has to lighten the load considerably, be concious of balance, alot more proprioception is involved which will increase neuromuscular pathways. have the person do this until adaptation occurs. if that person goes back to the old way of doing dbell rows, on that stable bench, chances are he will be stronger than before. why? because the body doesnt have to concentrate on the other factors that were involved with that unstable surface, now all it has to do is pull.
thats how using lighter weight, with equal or higher intensity, is used to break plateaus.
same can be applied to someone who shoulder presses 90lb dbells on a seated bench. if you sit them at the end of a bench with no back support, that guy is gonna be weak. his body isnt used to this type of movement and wont be able to just pick up the 90s and bang em out. you can literally wreck him with 45s in the same manner that the 90s may have made him feel.
intensity is the apparent feel of an exercise, related to maximum effort. how taxing it is mentally and physically. remember, strength increases are not always the result of muscular gain, the nervous system is the key component. better neuralmuscular control you have, the more you can recruit fibers.