Suffolk County Police say the incident happened at an LA Fitness on Deer Park Avenue in North Babylon just before 8 p.m.
They say two men got into an altercation and one of them fired a gun inside the gym.
ALSO READ | Woman grabbed from behind and attacked on New York City subway platform
Luckily, the bullet didn't hit anyone.
The other man did suffer injuries, however, they were not life-threatening.
The injured man was taken to a local hospital.
* More Long Island news
* Send us a news tip
* Download the abc7NY app for breaking news alerts
* Follow us on YouTube
Submit a News Tip