Endurance refers to a person's ability to exert themselves physically for an extended period of time and has two main components: cardiovascular endurance and muscular endurance. Low endurance can negatively impact activities in the water like catching waves or paddling out past the break. Signs of low endurance include soreness, shortness of breath, and dizziness. When working with someone with low endurance, it is important to provide encouragement, check in on how they feel, and respect what has worked for them individually. Techniques like energy conservation, pacing, breaks, positioning, and pursed lip breathing can help compensate for low endurance.