What is the difference between cardio and resistance training?

Cardio training primarily strengthens your cardiovascular system and burns calories during exercise, while resistance training builds muscle mass and increases metabolism for long-term calorie burning. According to the American Heart Association, cardio exercises like running, cycling, and swimming elevate your heart rate to improve heart and lung function, whereas resistance training uses weights or body weight to create muscle tension that promotes strength and muscle growth.

Cardio training, also called aerobic exercise, involves continuous movement that increases your breathing and heart rate for extended periods. This type of exercise primarily burns calories during the workout and improves cardiovascular endurance, lung capacity, and circulation. Common forms include brisk walking, jogging, swimming, dancing, and cycling. The Centers for Disease Control and Prevention recommends at least 150 minutes of moderate-intensity cardio per week for optimal health benefits.

Resistance training, also known as strength training or weight training, involves working against resistance to build muscle strength, power, and endurance. This includes lifting weights, using resistance bands, or performing bodyweight exercises like push-ups and squats. Unlike cardio, resistance training creates an "afterburn effect" called excess post-exercise oxygen consumption (EPOC), where your body continues burning calories at an elevated rate for hours after your workout.

The primary physiological differences are significant. Cardio training primarily targets your aerobic energy system and type I muscle fibers, which are designed for endurance activities. Resistance training mainly activates your anaerobic energy system and type II muscle fibers, which generate power and strength. Research published in sports medicine journals shows that resistance training increases bone density more effectively than cardio alone.

For optimal health outcomes, the American College of Sports Medicine recommends combining both types of exercise. Cardio provides immediate cardiovascular benefits and stress relief, while resistance training builds lean muscle mass that supports metabolism, functional movement, and injury prevention. A balanced approach typically includes 2-3 resistance training sessions and 150 minutes of moderate cardio weekly.

Your specific goals should guide your emphasis. If weight loss is your primary objective, combining both approaches maximizes results, as cardio burns calories immediately while resistance training builds muscle that increases your resting metabolic rate. For general health and longevity, both types of exercise address different aspects of physical fitness and disease prevention.

Related: Fitness & Exercise · What habits make an exercise routine easier to maintain? · What habits make an exercise routine easier to maintain? · How should a person return to exercise after illness?