However, alert level 2 means restrictions around social distancing still remain in place.
"We've moved our studios around," she said.
"Now we only have 12 people allowed per class, which means there might be reduction of numbers for some classes, but we have to ensure the safety of everyone.
"Each person in the class is to perform within their two metre square."
The gym also put into place a number of cleaning procedures.
"We have cleaning bottles for everyone, and towels, so people can wipe down the equipment once they have used it," she said.
"All the bottles are sanitised after they are used. We have stringent cleaning procedures in place because we want everyone to feel comfortable."
She said the eight personal trainers, including herself, were back to training with clients.
"As long as we stay outside the 2m bubble we are fine, so we are ensuring the workouts maintain that distance.
"We are just happy to be back. We had amazing guidance from our professional body Exercise Association of NZ and REPS around what was required under alert level 2, which helped with our decision to open."
Regular gym-goer Carly Nitschke said waiting the entire lockdown for her usual workout had been hard.
"I was eager to get back to the gym," she said. "I am really glad to be back."
She said while she was away, the gym ensured clients had avenues to stay fit.
"They were amazing, they let us borrow equipment and we had access to Les Mills on demand classes.
"Even my 3-year-old son got involved in the workouts, although it was harder to do them with him."
She said staying away from the gym also meant she had trouble staying motivated.
"It was harder to stay fit. I definitely put on a few kilos," she said.
"But doing a class in the gym means you want to keep going, there is motivation there.
"I am just looking forward to shedding those extra kilos."
Nitschke said she felt "quite safe" coming back to the gym in alert level 2 because the gym had taken every measure to ensure the safety of its clients.
