Conditioning
Seal Jack
The seal jack is a jumping-jack variation with your arms opening and closing at chest height. It trains coordination and cardiovascular endurance through repeated, rhythmic jumps.
- Beginner
- Compound
- Moderate injury risk
- Rest 30 sec
How to do it
- Stand with your feet together, arms extended forward at chest height, palms facing each other.
- Jump your feet slightly wider than shoulder-width as your arms open out to your sides.
- Jump back to feet together as your arms close in front of your chest.
- After the final landing, lower your arms to your sides.
Form cues
- Land quietly with soft knees.
- Keep your ribs over your hips.
- Keep your shoulders away from your ears.
Common mistakes
- Throwing your arms behind youStop opening your arms when they line up with your torso.
- Jumping too highUse only enough height to move your feet between positions.
- Losing the rhythmSlow down until your hands and feet reach their open or closed positions together.
Safety
Repeated hard or uneven landings can strain your ankles or knees, especially as fatigue reduces control.
- Use a level, nonslip surface with clear space on both sides.
- Start with a few slow repetitions before increasing your pace.
- End the set if your feet begin catching or your landings become unstable.
If jumping causes joint pain or you have balance limitations, choose a lower-impact version or ask a physiotherapist for guidance.
Muscles worked
Primary muscles
Secondary muscles
Equipment
No equipment needed.
Sets and reps
- Sets
- 2–3
- Target
- 15–25 reps
- Rest
- 30 sec
Count one complete open-and-close cycle as one rep.