What is a primary exercise precaution for individuals with diabetic retinopathy?

For individuals with diabetic retinopathy, avoiding extreme environments is crucial because fluctuations in temperature or humidity can potentially exacerbate their condition. Extreme heat could lead to dehydration and increased blood flow to the eyes, which might worsen the retinopathy. Similarly, cold environments can increase blood pressure, which is a significant concern for those with diabetic complications. This precaution helps in minimizing the risk of injury and ensuring that their exercise routine remains safe and effective.

The other options are less suitable. Exercising in cold weather, performing high-intensity workouts, and increasing workout duration might introduce risks that individuals with diabetic retinopathy may not be prepared to handle. High-intensity workouts can elevate blood pressure and lead to excessive strain, while prolonged workouts might lead to fatigue or dehydration, both of which can negatively impact blood glucose levels and overall safety during exercise.