Final answer:
To find a 1 RM, you should progressively increase the resistance until the lift cannot be completed, which effectively raises the intensity for muscle growth and adaptation.
Step-by-step explanation:
In assessing a 1 Repetition Maximum (1 RM), you should increase resistance progressively until the subject cannot complete the lift. For effective strength training, the intensity of the exercise needs to be continually increased to produce ever-greater results. By progressively lifting heavier weights, it becomes more challenging for muscles to move the load, leading to muscle adaptation and growth. To achieve even greater muscle mass, the load must be made heavier over time, as muscles adapt to the current load.