Exercise guide · Beginner · Compound
Frog Crunch: How to Do It & Muscles Worked
The frog crunch is a bodyweight abdominal exercise that targets the abs and also engages the hip flexors. It is performed lying on your back, curling your torso up while keeping your feet together and knees bent.
How to do the frog crunch
- Step 1: Lie flat on your back with your knees bent and feet flat on the ground.
- Step 2: Place your hands behind your head with your elbows pointing outwards.
- Step 3: Engaging your abs, lift your upper body off the ground, curling forward until your torso is at a 45-degree angle.
- Step 4: Pause for a moment at the top, then slowly lower your upper body back down to the starting position.
- Step 5: Repeat for the desired number of repetitions.
Sets, reps and programming
| Goal | Sets | Reps | Rest | Effort |
|---|---|---|---|---|
| Strength | 3–5 | 3–6 | 3–5 min | 1–3 reps in reserve |
| Muscle growth | 3–4 | 6–12 | 2–3 min | 1–2 reps in reserve |
| Muscular endurance | 2–3 | 12–20 | 1–2 min | 1–3 reps in reserve |
Ranges follow the ACSM position stand on progression in resistance training. Muscle grows across a wide range of loads when sets end close to failure (Schoenfeld et al., 2017), longer rests between heavy sets support strength and size (Schoenfeld et al., 2016), and stopping a rep or two short of failure works about as well as training to failure (Grgic et al., 2022). Estimate your working weights with the strength calculators.
Frog Crunch alternatives
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Sources
- American College of Sports Medicine. Progression models in resistance training for healthy adults. Med Sci Sports Exerc. 2009;41(3):687-708.
- Schoenfeld BJ, Grgic J, Ogborn D, Krieger JW. Strength and hypertrophy adaptations between low- vs. high-load resistance training. J Strength Cond Res. 2017;31(12):3508-3523.
- Schoenfeld BJ, Pope ZK, Benik FM, et al. Longer interset rest periods enhance muscle strength and hypertrophy in resistance-trained men. J Strength Cond Res. 2016;30(7):1805-1812.
- Grgic J, Schoenfeld BJ, Orazem J, Sabol F. Effects of resistance training performed to repetition failure or non-failure on muscular strength and hypertrophy: a systematic review and meta-analysis. J Sport Health Sci. 2022;11(2):202-211.
Step-by-step instructions and demonstration media are from the ExerciseDB exercise dataset.
This guide is general fitness information, not medical advice. Stop if an exercise causes pain and speak to a doctor or physiotherapist about injuries or health conditions before starting a new programme.