Summary

Jeff Cavalier introduces the “Pec Shredder,” a chest exercise inspired by Olympic gymnastics and the iron cross movement. The exercise applies the principle of time under tension to chest training using a cable crossover machine or bands. The demonstration draws on observations from the 2012 Olympics to highlight how gymnasts build impressive physiques despite being relatively small and lightweight.


Key Points

  • Olympic gymnasts are smaller than they appear — most male gymnasts weigh between 140–162 lbs at around 5’5”–5’6”, proving you don’t need to be large or heavy to look muscular and athletic
  • Time under tension is a core training principle — keeping muscles loaded continuously throughout a set drives greater muscle development than simply counting reps
  • Quality over quantity — it’s not how many reps you perform, but the quality of muscle engagement during each set that produces results
  • The Pec Shredder mimics the gymnastic iron cross — arms are extended out to the sides under heavy load, replicating the hardest position of the rings movement
  • The exercise can be performed without specialized equipment — a cable crossover machine, resistance bands anchored to high points, or pulley bars can all be used
  • 40 seconds of continuous tension is used as the target duration for the set, keeping the pectorals under load the entire time

Exercise Details

Pec Shredder (Iron Cross Cable Fly)

  • Target muscles: Pectorals (chest), anterior deltoids, stabilizing shoulder musculature

  • Setup:

    • Use a cable crossover machine with handles set high, or anchor resistance bands overhead at two points
    • Jeff uses 80 lbs per hand as a challenging load for demonstration
  • Proper form cues:

    • Back up slightly so arms are extended out to the sides at shoulder height — mimicking the top position of the gymnastic iron cross
    • Do not let arms drop all the way out; stop at a controlled lateral position
    • From the held position, slowly bring arms forward to engage the chest at the front, then slide back out to the sides
    • Maintain continuous tension throughout — no relaxing at any point in the movement
  • Common mistakes to avoid:

    • Releasing tension at the top or bottom of the movement
    • Going too heavy and losing control of the range of motion
    • Treating it like a standard rep-based exercise rather than a sustained-tension hold
  • Sets/reps recommendations:

    • Aim for approximately 40 seconds of continuous tension per set rather than a fixed rep count

Mentioned Concepts