Seated Frog Half to Full Sit-up
- Músculo objetivo
- —
- Equipamiento
- Body weight
- Parte del cuerpo
- Waist
- Tipo
- Strength
The Seated Frog Half to Full Sit-up is a core exercise that targets the rectus abdominis by combining a half sit-up and a full sit-up in a single rep, performed with the soles of your feet together and knees flared out in a frog position. The frog leg stance eliminates hip flexor dominance, placing more direct demand on the abdominals throughout the movement. It is an effective bodyweight drill for building core strength and endurance without any equipment.
Cómo hacer el Seated Frog Half to Full Sit-up
- 1Sit on the floor and bring the soles of your feet together, letting your knees fall out to the sides in a frog position. Place your feet roughly 30–45 cm from your hips.
- 2Lower your torso back toward the floor, keeping your core braced, until your shoulder blades are just above or lightly touching the ground — this is the starting position.
- 3Cross your arms over your chest or place your fingertips lightly behind your ears without pulling on your neck.
- 4Curl your upper body halfway up — roughly 45° from the floor — pausing briefly to feel the abdominals engage. This is the half sit-up phase.
- 5Without returning to the floor, continue curling all the way up until your torso is upright and your chest is close to your inner thighs. This is the full sit-up phase.
- 6Reverse the movement slowly: lower halfway back down, pause, then continue lowering all the way back to the starting position with control.
- 7That counts as one repetition. Complete your target reps while keeping the frog position and maintaining a smooth, controlled tempo throughout.
Consejos de técnica
- Focus on curling through the spine rather than jerking up with momentum — initiate each rep by pulling your navel toward your spine before moving.
- Keep your feet relaxed and soles together for the entire set; letting them slide apart reduces the hip-flexor-limiting benefit of the frog position.
- Exhale as you rise to the top and inhale as you lower back down to maintain intra-abdominal tension throughout the rep.
- If you feel strain in your neck, lower your hands toward your collarbone and make sure you are not pulling on your head.
- To increase difficulty, slow the tempo — try a 2-count up, 1-count pause at the half position, and 3-count descent.
Errores comunes
- Using momentum to swing up instead of controlled muscle contraction, which takes load off the abdominals and reduces effectiveness.
- Skipping the half-pause and treating the movement as a standard sit-up, losing the progressive overload benefit of the two-phase range of motion.
- Pulling the neck forward with the hands, which strains the cervical spine rather than working the core.
- Allowing the knees to rise and come together during the movement, which re-engages the hip flexors and defeats the purpose of the frog position.
- Dropping back to the floor quickly after each rep, which eliminates the eccentric load — the lowering phase is half the work.
Preguntas frecuentes
What muscles does the Seated Frog Half to Full Sit-up work?
The primary muscle targeted is the rectus abdominis. Because the frog leg position reduces hip flexor involvement compared to a standard sit-up, the abs must do more of the work across both the half and full range of motion.
Why is the frog leg position used instead of flat feet?
With feet flat and knees together, the hip flexors (iliopsoas) take over a significant portion of the sit-up movement. Placing the soles together and knees out slackens the hip flexors, forcing the rectus abdominis to generate more of the pulling force.
What is the difference between the half sit-up and full sit-up phases in this exercise?
The half sit-up phase (roughly 45° of torso elevation) maximises rectus abdominis tension at the most challenging part of the range of motion, while the full sit-up phase completes the crunch and brings the torso upright. Pausing at the halfway point before continuing up creates an extra challenge compared to a continuous sit-up.
Is this exercise suitable for beginners?
Yes, with a caveat. Beginners who lack core strength may find the half-pause phase difficult. Start with fewer reps and focus on controlled form — it is better to do 5 clean reps than 15 sloppy ones. You can also omit the pause initially and add it back once you build baseline strength.
How many reps and sets should I do?
For general core strength, 3 sets of 10–15 reps is a solid starting point. As the exercise becomes easier, increase reps, add a longer pause at the halfway point, or slow the eccentric (lowering) portion rather than simply adding more reps indefinitely.
