Lie on your stomach with your legs stretched out and your arms extended forwards. Actively engage your glutes, lower back and upper back. At the same time, lift your chest, arms and legs slightly. Hold this isometric position whilst looking at the floor (keeping your neck in a neutral position), maintaining even tension throughout your body and continuing to breathe calmly.
Attention:
Avoid hyperextension in the lower back (no pronounced hollow back – excessive local strain on the lumbar spine), do not hyperextend the neck (do not look straight ahead – tension is inevitable), do not lift the legs too high, do not engage the glutes (the back takes on too much of the workload), Do not let your arms hang passively (lack of tension in the upper back).
Lighten:
Lift only the upper body (focus on the upper back); lift only the legs (focus on the glutes); keep your arms by your side instead of stretching them out in front of you (shorter lever); lift very slightly (mini-hold).
Harden:
Extend your arms further forward (greater leverage); add extra weight (in your hands or on your ankles); do it on one side (one arm + opposite leg).
