Indicators of an effective warm-up routine include an increase in heart rate, improved flexibility, and enhanced range of motion. A good warm-up should include dynamic stretches and movements that prepare the specific muscles for the upcoming workout, gradually increasing intensity. If a person feels loose, energized, and ready for exercise, it is a sign that the warm-up was effective. Additionally, monitoring for any signs of discomfort can help prevent injuries and ensure readiness for the main workout.