The owner of Fitness Mania in the city of Riverside has vowed to keep the gym open, saying the business is operating "lawfully" and that any orders by the governor "are nothing more than suggestions."
Newsom recently reversed the state's reopening plan and mandated that many indoor businesses would have to close.
In certain counties, including Riverside, where Fitness Mania is located, Newsom ordered fitness centers shut down unless they can be modified to operate outside.
Fitness Mania did not indicate in a social media post that it would be offering outside arrangements.
"There are some small businesses that spend a fortune trying to help please the governor and do separate things like outdoor dining ... [putting] plastic walls up, doing all kinds of crazy things to help be safer, and then he goes and shuts us [down] again," gym owner Mike Ends told Los Angeles ABC station KABC. Ends could not be reached by ABC News for additional comment.
California is currently experiencing an increase in coronavirus cases, hospitalizations and deaths, according to an ABC News analysis.
On Tuesday, the state was one of a handful to hit a record number of hospitalizations.
Nevertheless, Ends said that he has received substantial support for his decision to stay open.
One customer, Oran Marlando, told KABC that if people are allowed to protest, they should be able to go to the gym.
"You got [thousands] of people in an enclosed area," Marlando said, referring to the nationwide protests against police brutality. "Whereby you got a 10,000 square foot gym [where the] closest person is maybe 15 feet close."
Officials were aware of the situation at Fitness Mania and were evaluating how best to proceed, according to KABC.
The governor's office notes in its order that the state's public health officer may take additional action if needed.
What to know about the coronavirus:
- How it started and how to protect yourself: Coronavirus explained
- What to do if you have symptoms: Coronavirus symptoms
- Tracking the spread in the U.S. and worldwide: Coronavirus map
Tune into ABC at 1 p.m. ET and ABC News Live at 4 p.m. ET every weekday for special coverage of the novel coronavirus with the full ABC News team, including the latest news, context and analysis.