Mountain climbers are a bodyweight exercise that engages multiple muscle groups at once, making it a full-body workout. The muscles worked during mountain climbers include:

• Shoulder muscles: The shoulder muscles work to support the body against gravity while holding a plank position.
• Triceps: The triceps are also engaged during mountain climbers.
• Chest muscles: The chest muscles are worked to support the body against gravity while holding a plank position.
• Serratus anterior: The serratus anterior is a muscle that runs along the sides of the ribcage and is worked during mountain climbers.
• Abdominal muscles: The abdominal muscles are engaged during mountain climbers to stabilize the body and maintain a plank position.
• Leg muscles: The legs generate power during mountain climbers, with the hip and thigh muscles working to pull one leg forward and the opposite leg involving the muscles of the hip, pelvis, and quads which lock the knee in extension, and the ankle, foot, and even toe muscles while this leg is driven back.

Mountain climbers are an explosive exercise that can help improve balance, agility, coordination, strength, flexibility, and blood circulation. They are also a cardiovascular exercise that can increase heart rate and burn calories. Mountain climbers can be modified to make them less challenging or more creative, and they can be performed anywhere without any equipment.