Which of the following best fits the definition of adaptation?

The definition of adaptation is best captured by stating that it refers to any variation that makes an organism better suited to its environment. Adaptations can be physiological, structural, or behavioral changes that enhance an organism's chances of survival and reproduction in its specific habitat. This encompasses a wide range of changes over time, including those necessary for coping with variations in climate, resources, and competition.

In a sports medicine context, understanding adaptation is crucial, as exercise and training programs aim to induce adaptations in the body, such as increased muscle strength, improved cardiovascular function, or enhanced endurance, allowing individuals to perform better in their respective sports. This biological principle highlights how organisms, including humans, can evolve and improve their performance in response to specific demands or stressors, ultimately leading to better overall function and health.