Muscle outlines from Body Muscles by Ivan Vulović, Apache 2.0 — regrouped and recoloured for Muscle Train.
Lie on back, knees bent, feet flat hip-width; arms at sides, palms down. Brace core (belly to spine), squeeze glutes. Drive hips up via heels (to ceiling). Top: straight knees-to-shoulders, hard glute squeeze, hold 1-2 sec. Lower controlled (resist gravity). Repeat 10-15 reps, 2-3 sets.
Drive heels (load glutes, not quads). Knees track toes (no cave/flare). Squeeze glutes hard at top (1-2 sec). Straight knees-to-shoulders (no sag/hyper). Slow/controlled reps (max engagement). Palms press floor (stability).
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