Translation of "muscle" into English

Les muscles de ses jambes s'étaient atrophiés durant les sept mois qu'il était cloué au lit.

The muscles in his legs had atrophied during the seven months he was bedridden.

Ils ont enfin compris qu'il y avait un cerveau derrière ces muscles.

They finally figured out there's some brains behind that brawn.

Ouais, on perd quelques kilos, on tonifie quelques muscles, mais on va nulle part.

Sure, you drop a few pounds... you tighten some sinews, but you still haven't gone anywhere.