I'm 87 and work out regularly. I feel as fit as I did 40 years ago.

• Peter Brenner was raised in a German orphanage after members of his close family died in the mid 1940s.
• At 18, he took up skiing as part of his job in border control, which sparked his love of sports.
• He has exercised throughout his life and, at 87, continues to go to the gym and bike long distances.

This interview is based on a conversation with Peter Brenner, 87, a retired senior food service manager from Westchester, New York. It has been edited for length and clarity.

I had to depend on myself very young in life. I was raised by a stepmother. She and my stepsister died of tuberculosis toward the end of World War II. I spent the following two years in a sanatorium.

Next, I was moved to an orphanage that operated like a military dictatorship. You had no freedom, as every minute of every day was scheduled. We played very little sport, but I did some soccer and swimming.

I did cross-country and downhill skiing

At 18, I was sent to work in professional food service before serving in the West German Border Police in the late 1950s. It involved a lot of long-distance running, swimming, and, best of all, skiing.

There was a lot of snow in the Bavaria area, and I would spend eight hours a day on cross-country and downhill skis. It suited me to organize sports for a change.

I immigrated to the US in 1962 and worked in food service in New York. In one job, I had a three-hour break between the lunch and dinner sittings, so I'd go to the gym at the YMCA almost every day.

It was a good foundation for keeping fit throughout the decades. In my 40s and 50s, cycling became my thing. Five times a week, I'd cycle between 30 and 40 miles after work — sometimes more — which helped me cope with stress.

There was no way I was going to stop exercising after I retired 20 years ago. I kept at it and took up Bikram yoga twice a week. I was skeptical at first, but I started to enjoy the poses in the big, hot room.

I avoid sugar and processed food

Three years ago, I hired a personal trainer, Agnes Malinari, for an hour weekly at my local New York Sports Club, where I've worked out ever since.

It involves a lot of weight and strength training, and I'm always very tired at the end of the session. I also do yoga twice a week and cycle up to 80 miles a week — similar to what I did in my 40s. I also keep fit by gardening.

I eat healthily, avoiding sugar and processed foods as much as I can. Breakfast is usually bread or cereal. Lunch is often yogurt, fruit, or soup. For dinner, I'll have a protein such as fish or chicken with fresh vegetables from the local farmers market.

Still, I don't deny myself a couple of glasses of wine in the evening.

People ask me what my secret is for looking and behaving like someone much younger than my age. I don't like to use the word "secret" because it sounds arrogant.

I feed my mind with theater

Instead, I put it into context by describing my childhood, when I grew up without money and had little control. It makes me appreciate what I have now.

It might be the opportunity to feed my mind by going to the theater or having friends around for lively discussions.

Looking back, my past forged strength and resilience. They are vital characteristics that have helped me through life.