reported that a tiger sand shark attacked the 17-year-old during the training exercise.
The attack left him with foot injuries. He was taken to hospital, where he received multiple stitches.
"I didn't really feel the bite at first," Mullins said. "My adrenaline was rushing right away.
News 12 reported that Mullins seems to be recovering from the injury but is walking with a limp.
During the training exercise, Mullins was playing the role of the victim in need of a lifeguard's help when ironically, lifeguards did have to help him when the shark attacked.
"I was like 'Oh my God, I've got to go,' - it was crazy," Mullins said. "I thought it was following me, so I was freaking out..."
After the attack, swimming at Ocean Beach on Fire Island was prohibited for an hour. Once it was allowed again, visitors could only go waist-deep in the water.
This is the second time a shark attacked a lifeguard during a training exercise.
The first attack, which took place on July 3, happened at Smith Point Beach in New York. Lifeguard Zach Gallo was bitten by a shark while completing the training exercise.
Like Mullins, Gallo also received stitches during his hospital trip.
Recently, a teen girl lost her leg after a shark attack at Keaton Beach in northwestern .
Regardless of the attack, the two men look forward to returning to the water.
"I'm looking forward to getting back," Mullins said. "I'll be back on Sunday - training for the test again. Just hoping not to get bit again."