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Balance Trainer Side Star Plank
A challenging unilateral core exercise on a balance trainer, targeting the obliques, glutes, and shoulders for high stability and anti-lateral flexion strength.
About Exercise
Equipment
Balance Trainer, Body Weight
Difficulty
4/5 • Advanced
Primary Muscle Groups
Obliques, Glutes
Secondary Muscles
Shoulders, Abs
Popularity Score
4
Goals
Training Style
Setup Requirements
Requires Rack
No
Requires Bench
No
Requires Spotter
No
Space Needed
Small
Noise Level
Low
Muscle Breakdown
View Muscle MapObliques
10/10External Obliques, Internal Obliques
Glutes
8/10Glute Medius
Abductors
6/10Glute Medius, TFL
Shoulders
5/10Medial Delts, Anterior Delts
Abs
4/10Rectus Abdominis, Transverse Abdominis
Programming
Typical Rep Range
8-15 reps
Rest Between Sets
45-90 seconds • Rest briefly between sides, or up to 90 seconds between full sets.
How to Perform
Place the dome side of the balance trainer on the floor. Start in a side plank position with the supporting forearm centered on the dome and stacked feet placed together on the ground.
- Lift your hips into a straight side plank, stacking the elbow directly under the shoulder.
- Engage your core and glutes to maintain a rigid, straight line from head to heels.
- Simultaneously lift your top arm toward the ceiling and the top leg upward.
- Hold this extended position briefly, resisting rotation or lateral bending.
- Slowly return the arm and leg to the starting side plank position.
- Complete all required reps or time on one side before switching.
Coaching Tips
Form Cues
- Hips high and forward.
- Press the forearm hard.
- Lift top arm and leg.
- Resist the lateral sway.
- Keep body in straight line.
Breathing
Inhale before starting the plank and maintain tight core bracing throughout the movement, using short, shallow exhales if needed.
Tempo
2-1-2
Range of Motion
The core should remain locked and stable. Lift the top leg and arm simultaneously until they are roughly 45 degrees away from the torso.
Safety
Safety Notes
- Ensure the balance trainer is centered and stable before initiating the plank.
- Stop immediately if sharp pain occurs in the shoulder or lower back.
- Master the standard side plank before attempting this unstable variation.
Spotting
Not recommended; focus on controlling the movement and stability. Drop the hips to the floor if stability is lost.
Common Mistakes
- Letting the hips drop toward the floor.
- Allowing the torso to rotate or lean forward.
- Sacrificing core stability for greater limb elevation.
- Bending the supporting arm.
When to Avoid
- Acute shoulder injury or impingement.
- Severe, radiating lower back pain.
- Recent core surgery or uncontrolled instability.
Flexibility Needed
- Good shoulder stability in pressing position.
- Functional hip abduction range.
Build Up First
- Competency in standard forearm side plank.
- Ability to maintain balance on a single forearm on unstable surfaces.
Also known as
Star Plank on Balance Trainer, BOSU Side Star Hold, Unstable Side Plank Lift
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