The double under is a jump rope skill where the rope passes under your feet twice per jump, building coordination, speed, and cardiovascular endurance. It’s a popular movement in high-intensity double under workouts, often used to spike heart rate and improve timing under fatigue.

In this workout, double unders challenge your footwork, rhythm, and breathing, making them a key tool for improving overall conditioning. Whether you're linking sets or working on consistency, double unders are a fast-paced way to level up your engine.

The push-up is a foundational bodyweight movement that strengthens the chest, shoulders, triceps, and core. A staple in any push-up workout, it’s effective, scalable, and requires no equipment — making it perfect for all fitness levels.

In this workout, push-ups develop upper body endurance, stability, and control, especially under fatigue. Whether performed strict, hand-release, or elevated, the push-up is a timeless movement that builds strength and resilience.

The air squat is a fundamental bodyweight movement that builds lower body strength, mobility, and endurance. As a key component of many air squat workouts, it targets the quads, glutes, hamstrings, and core—all without equipment.

In this workout, air squats help develop proper squat mechanics, balance, and muscular stamina, making them perfect for warm-ups, high-rep conditioning, or scaling strength-based movements.

The bar muscle-up is a high-skill gymnastics movement that combines a powerful pull-up with a dip, taking you from below the bar to above it in one fluid motion. A highlight of many bar muscle up workouts, it demands upper body strength, timing, and core control.

In this workout, bar muscle-ups challenge your grip, pulling power, and technique—making them a true test of gymnastic capacity. Whether strict or kipping, the bar muscle-up is a milestone movement in CrossFit and functional fitness.