By Carolyn Schultz Eggert

Last summer, I drove my 93-year-old neighbor to the supermarket. When we got home and pulled into her driveway, Dorothy asked me to come over to the passenger side of the car.

I offered her my hand. No, she said, she didn’t want my help. She wanted me to observe.

Dorothy slowly emerged from the passenger seat, leaving the car gracefully and without any distress. “This is how I want you to get out of a car when you are my age,” she told me. “So keep exercising.”

I will never forget that.

When I first moved to the neighborhood, I would frequently see Dorothy driving out of our street. Eventually I learned that she had a specific destination on Mondays, Wednesdays and Fridays. She was off to the gym across town where she took water aerobics and exercise classes.

I thought she was amazing when I first met her. She was 78 and always on the move. She didn’t have to depend on a fitbit activity tracker to get her going.

Her fitness routine kept her relevant and independent. She was able to get in and out of a car, play bridge and when she had time, take walks with me.

Now that I’m moving through middle age faster than I care to admit, I’ve thought a lot about what it means to live a long and healthy life. I have watched the aging of my grandparents, parents and friends like Dorothy. Everyone grows old differently. My take away? Staying well means staying fit.

But how does someone prepare to live a enjoyable old age?

I have been vigilant about exercise and nutrition for most of my adult life. The media, along with my health care providers, have convinced me that combined, they hold the key to a long and healthy existence. When I lose momentum, Dorothy motivates me.

How to make the most of your diet

I recently turned 53 and have noticed a few physical changes despite my somewhat disciplined lifestyle. My abs are morphing to the point where I can see spillover when I wear certain pants. My immediate solution: Give away those pants. Dorothy’s solution: Step up the exercise and think about what you are eating.

I’ve added strength-building exercises to my walking 10,000 steps a day. I’m also reducing my intake of frozen yogurt with jimmies.

But why, when you think you’re doing everything right, do you gain weight?

Experts tell postmenopausal women like me to “eat less and exercise more.”

I’d like to blame the hormonal changes of menopause. While they are part of the problem, simply getting older predisposes women (and men) to gaining weight. Lifestyle and genetics play a role too in the aging process.

Ultimately, maintaining a healthy weight and staying physically active decreases the risk for certain cancers, heart disease, stroke, diabetes, high blood pressure, osteoporosis and depression.

What I think about most is how easily Dorothy moves about, even at age 93. I hope that I live a long life like her, and when I’m her age, my goal is to get in and out of a car like she does.

Carolyn Schultz Eggert is a freelance writer and owner of e.e.Companions, which helps seniors remain active and relevant despite physical or emotional challenges.