Final answer:
The principle of individual differences in biology states that the rate and magnitude of adaptations to training are limited by our differing genetics.
Step-by-step explanation:
The principle of individual differences in biology states that the rate and magnitude of adaptations to training are limited by our differing genetics. This means that different individuals may respond differently to the same training program due to their genetic makeup. For example, some people may naturally have a higher capacity for aerobic exercise while others may be more genetically predisposed to strength training.