Exercise guide · Intermediate · Compound

Barbell Lying Extension - Core Variation: How to Do It & Muscles Worked

The barbell lying extension, also known as a skullcrusher, is a strength exercise targeting the triceps. It involves lying on a bench and lowering a barbell towards the forehead by bending the elbows, then extending the arms back up.

Primary muscles
Triceps
Secondary muscles
Shoulders
Equipment
Barbell
Level · type
Intermediate · Compound
Demonstration of the barbell lying extension - core variation
Front view: muscles worked by the barbell lying extension - core variation. Primary: triceps. Secondary: shoulders.
Back view: muscles worked by the barbell lying extension - core variation. Primary: triceps. Secondary: shoulders.
Primary Secondary

How to do the barbell lying extension - core variation

  1. Step 1: Lie flat on a bench with your feet flat on the ground and your head at the end of the bench.
  2. Step 2: Hold the barbell with an overhand grip, hands shoulder-width apart, and extend your arms straight up over your chest. Maintain core form throughout.
  3. Step 3: Keeping your upper arms stationary, slowly lower the barbell towards your forehead by bending your elbows.
  4. Step 4: Pause for a moment, then extend your arms back up to the starting position.
  5. Step 5: Repeat for the desired number of repetitions.

Sets, reps and programming

Suggested sets, reps and rest for the barbell lying extension - core variation by training goal
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.

Barbell Lying Extension - Core Variation alternatives

More exercises that train the triceps as their main target:

More triceps exercises

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Sources

  1. American College of Sports Medicine. Progression models in resistance training for healthy adults. Med Sci Sports Exerc. 2009;41(3):687-708.
  2. 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.
  3. 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.
  4. 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.