Effective hydration during exercise is indicated by several factors including urine color, thirst level, and performance metrics. A light yellow urine color typically suggests adequate hydration, while darker urine may indicate dehydration. Additionally, individuals should remain proactive by monitoring fluid intake before, during, and after exercise. Monitoring physical performance and energy levels can also provide insight into hydration status. It's recommended to drink fluids regularly, particularly electrolyte-rich drinks during prolonged activities to maintain optimal hydration levels.