After heart attack, 'Biggest Loser' host Bob Harper 'back to square one'

After a heart attack in February, Bob Harper, a personal trainer and host of the NBC show "The Biggest Loser," is on the road to recovery.

The 51-year-old recently shared an Instagram video of himself walking on a treadmill.

"Well while all of my @crossfit family is getting ready for 17.3, I'm walking on a treadmill doing a stress test. Talk about starting back at SQUARE ONE. I plan on being the BEST STUDENT. #heartattacksurvivor," the caption said.

Harper has said that his family has a history of heart problems. Since his heart attack, he has been spending more time at home and with loved ones. He wears a heart monitor daily and has made some lifestyle changes -- including switching to a Mediterranean diet.

Mediterranean diets have been linked to lower risk of cardiovascular problems and better-managed weight. The diet involves eating items that are rich in vegetables, fruits, nuts, beans and peas, unrefined grains, olive oil and fish. Meat, dairy and saturated fats are eaten minimally.

Harper also posted images of himself visiting friends, going out for the first time since the heart attack -- he saw the Broadway play "Miss Saigon" -- and doing his "afternoon reading," the book "Heart 411."

In late February, Harper shared a photo of himself in a hospital gown.

"Well I guess you all heard what happened. Two weeks ago yesterday I had a heart attack. I am feeling better. Just taking it easy," he said. "I want to thank everyone for the outpouring of messages and support. It feels good to be cared about. I've been home for 8 days now."

The health and fitness expert has over 20 years of experience helping others get fit and lose weight. Harper has written three bestselling books on fitness and has appeared on 17 seasons of the NBC show "The Biggest Loser" since 2004.