Related Clues:
- Situps tighten them
- Center of a pear
- Apple's inner part
- Midsection, in brief
- Crunch focus
- Part of apple
- V-sits work them
- They get harder the more you work out
- 'Crunched' muscles
- Plank's target, at the gym
- Muscles strengthened by planking
- Muscles worked by situps
- Workout focus
- 'Washboard' muscles, informally
- Muscles tightened by planking, in brief