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The HIT MethodAn independent guide to high-intensity training

Seal Jack: How to Do It, Muscles Worked and Easier Options

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The seal jack is a beginner, high-impact cardiovascular exercise that modifies the traditional jumping jack by having your arms clap in front of your chest. This horizontal arm movement shifts the upper body focus to your pectoralis major and posterior deltoids while you jump.

Because it requires no equipment, you can perform seal jacks anywhere to build coordination and endurance. The jumping motion engages your calves, while your hip abductors work to push your legs outward on every rep.

Exercise data

Impact
High
Level
Beginner
Equipment
None
Main muscles
pectoralis major, posterior deltoids, calves
Also working
hip abductors
Movement
A jumping jack with the arms clapping in front of the chest
Low-impact swap
step-out seal jack

How to do a seal jack

Stand tall with your feet together and your arms extended straight out in front of your chest, palms facing each other.

  1. Jump up slightly to spread your feet wider than shoulder-width apart.
  2. Simultaneously open your arms wide to the sides, keeping them at shoulder height.
  3. Land softly on the balls of your feet with your knees slightly bent.
  4. Jump again to bring your feet back together.
  5. As you jump your feet inward, clap your hands together in front of your chest.
  6. Repeat the sequence in a continuous, rhythmic motion.

Form cues

  • Keep your arms parallel to the floor.
  • Land softly on the balls of your feet.
  • Maintain a slight bend in your knees.
  • Squeeze your chest as you clap your hands.

Common mistakes

  • Dropping the arms. Keep your arms at shoulder height throughout the entire movement to fully engage your chest and upper back.
  • Landing flat-footed. Always land on the balls of your feet to reduce the impact on your joints and protect your knees.
  • Bending the elbows too much. Keep your arms relatively straight with only a soft bend at the elbow to maximize the range of motion.
  • Losing core tension. Brace your abdominal muscles to prevent your lower back from arching excessively as you swing your arms wide.

Easier and harder versions

Easier

  • step-out seal jack

Using it in intervals

Seal jacks work well as a dynamic warm-up or as an active recovery move between intense strength intervals. When pushing for maximum effort in a high-intensity circuit, focus on your arm height and foot speed. As fatigue sets in, you might naturally let your arms drop or your landings become heavy. Pay close attention to a soft, controlled landing and keep your hands at chest level to maintain the intended muscle engagement.

Formats that suit this move: Tabata Workout, 30/30 Intervals.

Impact note. This move involves jumping. If impact bothers your knees, ankles, back or pelvic floor, use the low-impact swap: step-out seal jack.

Similar moves

When to stop and see a doctor

  • Sharp pain in your knees or ankles upon landing.
  • Pinching sensations in your shoulder joints.
  • Unexplained chest pain or severe shortness of breath.

This page is general information, not medical advice. If you have a heart condition, high blood pressure, joint problems, are pregnant or have been inactive for a long time, talk to your doctor before starting vigorous exercise.

How this page was made. Exercise data (impact, level, equipment, muscles) was compiled by our editors as a general anatomy and coaching guide. Text drafted with AI assistance and checked by the Training Desk; see how we write. Last checked October 2026.