Dr. Robert Willix Jr. is training to compete in next year’s Ironman World Championship in Kona, Hawaii. This would be impressive for anyone, but it is more so for Willix, when you consider he is 75, and the last time he competed in the Ironman was more than three decades ago.

“It’s wonderful to be in training again. It may be harder for me to get motivated then when I was in my 40s, but once I get started, I get the same great feeling,” Willix tells Newsmax Health, after just wrapping up a 50-mile bike ride.

Willix is founder and CEO of Enlightened Medicine in Boca Raton, Fla., an integrative medical practice that focuses on anti-aging medicine and the prevention of chronic disease.

He spent the first 40 years of his career as a cardiovascular surgeon, pioneering the first open heart surgery program in South Dakota. Willix then shifted his focus, and carved out his second career as a nationally known anti-aging expert.

Willix is the author of “Healthy at 100: 7 Steps to a Century of Great Health,” among other books. He’s also a lifelong athlete who has completed14 marathons, along with triathlons.

The core of his program is his belief in epigenetics.

While genetics emphasizes the importance of heredity in terms of the diseases for which people are prone, epigenetics focuses on the way those genes are expressed. By adopting healthy habits, people can change their genetic destiny, Willix says

“We understand aging a lot more now and we know one thing – the idea that genetics is all-important is a lot of hooey. It’s less important than we used to think it was, but it’s up to people to take charge of their health,” he adds.

Although Willix inherited longevity genes – his father died at the age of 86 while preparing for a marathon – this will mean nothing if he fails to maintain a healthy lifestyle, Willix believes.

“The children of today will not outlive their parents because they are sedentary and sit around. If you don’t participate in an active life, your aging is going to be horrible,” says Willix.

To Willix, exercise is key, but so is nutrition.

“I’ve been a vegetarian since 1977. I feel best that way but it's not necessarily for everyone. The Mediterranean diet has stood the test of time as well,” Willix notes.

The Mediterranean diet emphasizes fruits and vegetables, nuts, grains, olive oil (as opposed to butter), and grilled or steamed chicken and seafood (as opposed to red meat).

Willix will learn if he is going to Hawaii when he competes on Nov. 5 in the Panama City Beach qualifying event.

Here are Willix’s secrets to becoming an Ironman and aging well – no matter how old you are.

• Never retire: You need to keep both your mind and body active in order to counteract the aging process, he says, adding that he knows "too many people who retired and died only a year or two later."
• Stay physically active: Swimming, biking, and running are great, but you don’t necessarily need to do these activities. Exercise can be playing golf, tennis, gardening, or any activity that that gets you to use your muscles is fine.
• Eat healthy. What you eat affects your risk of getting Alzheimer’s disease. You don’t need rice, potatoes, bread, alcohol, or sugar. Consider where food comes from and choose whole, natural foods, not processed ones. "If it comes in a box, it’s not food," he says.
• Meditate daily. Life is stressful, so you need to do something that quiets your mind, whether it’s meditating, yoga, or tai chi.
• Family counts. Stay connected to your family and friends. "This is the way to make sure there is peace and love in your life," he says.
• Be of service. People genuinely want to help others, and this is a way you can add purpose to your life.
• Live in the moment. You can plan for the future, but you can’t do anything to change it, so don’t waste your time worrying. "Positive thoughts create positive chemistry in your body," says Willix.