Why do cold-blooded animals have slower heart rates?

Cold-blooded animals, or ectotherms, rely on external temperatures to regulate their body heat, which affects their metabolic processes. Their slower heart rates are a reflection of their lower metabolic demands compared to warm-blooded animals. As their body temperature decreases, so does their metabolic rate, leading to a reduced need for oxygen and a slower heart rate to maintain bodily functions efficiently. This adaptation allows them to conserve energy in varying environmental conditions.