Weightlifting, also known as strength training or resistance training is the type of exercise that falls under the category of anaerobic exercise. Cardio activity causes people to spend lengthy periods of time breathing in extra oxygen as their heart rate increases. This starts a cycle of increased blood flow from the heart to the lungs, with oxygen being the main source of energy until the completion of the workout. Contrarily, anaerobic literally means without oxygen because this is the type of exercise that needs immediate energy. It gets this by relying on stored glucose for quick fuel. Weight training workouts are generally shorter but more strenuous than cardio.
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