Bob Harper Opens Up About Major Heart Attack: 'I Was Dead'

"I was in full cardiac arrest."

Bob Harper is grateful to be alive.

The Biggest Loser
host appeared on the Today show on Tuesday, where he talked about suffering a near-fatal heart attack in late February. The 51-year-old personal trainer was exercising at a gym in New York City, when he suddenly collapsed.

"I had what they call a 'widow-maker,'" he told Today co-host Savannah Guthrie. "It was a six percent survival rate, and the fact that there were doctors in the gym when I had the heart attack saved my life."

WATCH: 'Biggest Loser' Host Bob Harper Confirms He Suffered a Heart Attack, Says He's 'Feeling Better'

"I was in full cardiac arrest," he added. "My heart stopped. Not to be dramatic, but I was dead. I was on that ground dead."

Harper said he doesn't remember anything about the fateful day, when two doctors performed CPR on him and administered a defibrillator, which delivers a dose of electric current to the heart. He woke up in the hospital a few days later after going into a coma.

"It was super scary for me because I woke up and I was so confused," he shared. "I was like Dory from Finding Nemo because I had this short-term memory, so I was reliving the heart attack over and over again. I was like, 'Wait, why am I here? What happened to me?' And 10 minutes later I was asking the same thing, and getting super emotional."

Harper said that the "hugely shocking" incident did teach him an important lesson -- that it's important to know your health.

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"I've learned a lot about myself," he acknowledged, adding that the experience was a huge wake-up call. "I've learned a lot about the fact that genetics played a part in this. It is so important to know your health."

"I'm a guy that lives a very healthy lifestyle, very regimented," he continued. "I work out all the time, but there were things going on inside of me that I needed to be more aware of. And I strongly encourage anybody that's listening right now to go to the doctor, get your cholesterol checked, see what's going on on the inside, so it doesn't happen to you -- what happened to me."

Watch the video below for more on Harper's scary heart attack.