Article in health club (needle) occasionally used for heavenly body (8)
I believe the answer is:
ganymede
'for heavenly body' is the definition.
(I've seen this before)
'article in health club needle occasionally' is the wordplay.
'article' becomes 'an' (indefinite article).
'in' indicates putting letters inside.
'health club' becomes 'gym' (I've seen this in another clue).
'occasionally' indicates alternate letters.
The alternating letters of 'needle' are 'ede'.
'an' going into 'gym' is 'ganym'.
'ganym'+'ede'='GANYMEDE'
'used' acts as a link.
(Other definitions for ganymede that I've seen before include "Beautiful cupbearer to the gods" , "Trojan youth" , "Beautiful youth's" , "heavenly body seen by Jupiter" , "Cupbearer of Greek gods - largest moon of Jupiter" .)