Which of the following is considered an intrinsic risk factor for injury?

Age is considered an intrinsic risk factor for injury because it relates to the individual characteristics and physical condition of an athlete. As people age, their bodies undergo various physiological changes that can affect their strength, flexibility, balance, and overall physical resilience. These changes can increase the likelihood of sustaining injuries during physical activities. For example, older athletes may have a decreased range of motion or slower reaction times, contributing to a higher risk of injury.

In contrast, the other options represent extrinsic risk factors, which are external to the individual. Weather conditions involve elements like temperature, precipitation, and wind, which can impact performance and safety during activities but are not inherent to the athlete. The type of sport influences injury risk based on the specific demands and physical actions required, yet it does not stem from the individual’s characteristics. Lastly, equipment used, while critical to safety and performance, does not relate to the athlete's intrinsic qualities. Each of these extrinsic factors can contribute to injury risks but are not tied to the personal attributes of the individual athlete like age is.