Final answer:
The principle that loads must be increased for adaptation refers to the necessity of escalating the intensity of exercises, like weight lifting, to achieve continuous muscle growth and development.
Step-by-step explanation:
The principle that loads must be increased to foster adaptation is fundamental to effective strength training and muscle development. When engaging in activities like weight lifting, the weights lifted must progressively become heavier to challenge the muscles further. This is because muscles will adapt to a certain level of stress, and without increasing this stress, no additional muscle growth will occur. Similarly, the concept of adapting to increased demands is observed in Le Châtelier's principle in chemistry, though the context there is chemical equilibria rather than physical strength.