Reverse plank

Create a stable line through the head, trunk and pelvis and keep abdominal tension for the prescribed time. Breathe normally without letting the lower back sag. Prioritize control over speed. Maintain useful tension through the range and deliberately reset the starting position before the next repetition.

Do not turn the final repetitions into fast or partial movements. Aim to load abdominals, glutes and hip flexors and lower back without sacrificing position; at beginner level, progress control first and then add load, repetitions or complexity.