Gyms are being reminded that any facility running outdoor classes must limit numbers to four.
That's the advice from Ireland Active, which represents the industry, during phase one of restrictions being lifted.
It follows evidence that outdoor fitness classes are taking place in groups of more than four today.
Ireland Active says social distancing must be observed, gyms should ensure people pre-book a space, and people cannot access the facility to use changing rooms or toilets.
Personal trainer Karl Henry says he has heard reports of gyms running classes outdoors with more than four people:
"As far as I'm aware there's a maximum of four people allowed in a class situation.
"And there are guidelines in terms of signing off a consent form that you haven't been in touch with anyone who's had Covid-19."