Answer:

spandex

Answer	Crossword Clue
SPANDEX	Fiber known as elastane in Europe
SPANDEX	Lingerie synthetic
SPANDEX	Stretchable fabric

SPANDEX	Stretchy fabric
SPANDEX	Shapewear fabric
SPANDEX	Singlet synthetic
SPANDEX	Cyclist's wear
SPANDEX	It stretches during exercise
SPANDEX	Leotard fiber
SPANDEX	Gym bunny's fabric
SPANDEX	Stretcher at the gym

SPANDEX	Material for The Rock
SPANDEX	Lycra, e.g.
SPANDEX	One of the new stretch fibers.
SPANDEX	Polyurethane fiber
SPANDEX	Hip hugger?
SPANDEX	Exerciser's wear
SPANDEX	Gym wear
SPANDEX	Something to exercise in

SPANDEX	Stretcher at the gym?
SPANDEX	It stretches at the gym
SPANDEX	Wrestling singlet fabric
SPANDEX	Swimsuit material
SPANDEX	Athletic wear named for an anagram of what it does