First workout – Huge stimuli and huge changes to your body
Second workout – Slightly less stimuli and less change to your body.
Third workout – Less response again.
Fourth workout – Marginal adaptation/benefit at all.
Once you’ve completed the 2-4 repeats on a workout, you’ll need to change it up (this is why most well designed programs will consist of 2-4 week cycles, followed by a big change of exercises or rep/set).
This is also why most gym guys/gals will try in vain to chase the same ‘gainz’ they got on a favorite program from yesteryear, but with little to no success.
A great technique that I learned many years ago to smash through such training plateaus is Cluster Sets.
Cluster sets are a form of what we call ‘Intensification’ training. That is a phase of training where we increase the intensity (intensity is measure by the load lifted for each set, not how out of breathe or how much the muscle burns).
The opposite modality to ‘Intensification’ is ‘Accumulation’.
Intensification – Heavier weights. Reps of 1-6. Sets to range between 6-12 with long rests.
Accumulation – Moderate weight. Reps of 7-20. Sets to range between 4-10, shorter rests focusing on the pump.