Working alongside Virgin Active's internal creative team, BMB, which was appointed without a pitch, will create a campaign to promote the gyms and their services.
The appointment comes in the wake of Virgin Active's £650 million acquisition of the larger Holmes Place chain of health clubs last September. Under the deal, Virgin Active now has 72 clubs in the UK and a member base of 324,000.
The chain is understood to be backing its purchase with an investment of £20 million, a portion of which has been earmarked for an ad campaign. Goodstuff will handle media planning, while Manning Gottlieb OMD will oversee media buying.
Andrew McGuiness, the BMB founding partner, said: "Virgin Active is one of the few true brands in this sector. Our task is simple: deploy our creativity to help it exploit this."
Peter Brennan, the Virgin Active UK managing director, added: "We can think of no other agency that is better."