Each gym has to pass a virtual inspection, no indoor group classes are allowed and swimming pools will remain closed.
Still, this is a day lots of people have been waiting for, with many making appointments to get in to fitness facilities across the city.
Many have said they are returning with confidence in new safety measures now in place.
Eyewitness News was at a Blink Fitness facility in Park Slope, Brooklyn well before dawn.
Before the gym opened, Justin Rushing and Shanchelle Mitchell were lined up and ready to make up for lost ground.
"I haven't been able to hit legs at all, now's the time," Rushing said.
"Every day I've been counting down the days," Mitchell said. "It's a good day!"
At Crunch Gym in Union Square, gym goers said it felt like the first day of school.
Eyewitness News found customer Sharon Moore wiping down the treadmill she just used -- one of many changes at gyms - and she said felt the gym was doing what they can.
"There's a risk anywhere, but I felt they were trying to protect us," she said. "We'll see how it goes."
The Crunch staff has spent months getting ready, blocking off and spreading out machines for social distancing. Signage is up, sanitizer is everywhere and the air filtration system meets standards when it comes to COVID-19.
"It's going to take a few months to kind of climb out of this hole, this big void we've had," CEO of Crunch Keith Worts said.
Worts said he had to lay off almost 3,000 employees and is negotiating with landlords about rent owed.
But with all of that, he says safety is a priority and getting everyone back on track.
Gyms in the city can only operate at 33% occupancy which in this space, which is roughly 20,000 square feet, only 107 people will be allowed inside at one time
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Those returning for their workouts now need to wear a mask at all times, and gyms can only operate at one third of their normal capacity.
Gyms now have markers to ensure social distancing.
And owners have filled out online forms saying they've taken all the state-mandated precautions.
While gyms in other parts New York were allowed to open last week, the city experienced a delay due to the difficulty getting health inspectors to all the gyms.
That's because those same health inspectors were needed in schools.
Ultimately the city decided to shift to virtual inspections.
"We worked with the state on virtual as a way to get started, because the timing is so tough," said Mayor Bill de Blasio. "The virtual inspections are a way to at least allow our health inspectors to get started. We will then be doing ongoing in-person inspections as those inspectors' time frees up after school and child care gets going."
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