I know my story is your story, too.

Five years ago, I turned 50. It felt as though everything changed overnight. In my 20s, 30s and 40s, I charged ahead with life, first throwing myself into my career -- I worked as a magazine publisher -- and then, in my late 30s, meeting my husband, getting married and having children. Those busy years almost seemed like one long decade, during which I didn't feel any different about how I looked or acted. I never stopped to think about what impact the way I was living might have down the road.

Then, one day, I woke up and... I was 50. Suddenly, I would catch myself in the mirror and notice my drying skin, crow's feet, the way my hair looked. I felt aches and pains for the first time. I also began to gain weight. It wasn't a huge amount, but it was steady and showing no signs of slowing down. Weight gain can often be a part of the aging process, especially after we go through menopause. However, I remember reading somewhere that five pounds was an acceptable amount to gain, but anything more was another term for "letting yourself go."

I knew that if changes weren't made -- and fast -- I'd be heading into my 50s at a terrible disadvantage. Wanting to stay healthy, fit, energetic and productive for the rest of my life, I was ready to change -- and possibly save -- my life. I didn't simply want to think, 'I'm 50 now, that's it, my life is over,' I wanted to be fearless after 50. There's been a lot written about how women cease to exist once they hit this age. Despite our great consumer power, post 50 women are often dismissed as invisible, and seen as neither young nor interesting enough. This is so wrong, and I was depressed thinking that this was my future.

But, there was more...

When I turned 50, I found myself asking the 'what if' questions: what if I get sick or have a heart attack? What if I get Alzheimer's? What if I get cancer? Do I already have cancer without knowing it? I looked around and people my age were having strokes, struggling with depression, developing diabetes. It's not that younger people didn't have some of these health concerns, but that after 50 they seemed all too common. And the closer I looked, the more I realized that many of these health issues were in our control. The more I thought about it, the more questions I had. I began to wonder if there were tests I should be getting and asking what I could do to make sure that I lived a healthy life.

Like many women, I had gone a long time without doing simple things that could positively affect my health. Many of us are part of the so-called sandwich generation -- caught between looking after our children and caring for elderly parents -- and I realized life had kept me busy taking care of others, yet failing to do the right things for myself. Sleeping enough and exercising daily had come to seem like an indulgence, even as I made sure that my family was well fed and well rested. So I embarked on a quest to discover how ordinary women could look and feel their best in their 50s and beyond. I soon realized that what I wanted was the best information I could find. I began to contact beauty experts and financial experts. I talked to the renowned hairdresser Frederic Fekkai, and to fashion designer Diane von Furstenberg. I tracked down women's health specialists and exercise gurus, nutritionists and make-up experts. And, after hearing their advice, I took it.

I started going for slow runs with breaks for walking every day and learned how to do push-ups and other exercises to prevent osteoporosis. I went for annual health checks. I changed the way I ate and dropped the bad habits I'd slipped into. Where I had once spent my time dieting instead of eating, I began to pay attention to what I ate and to eat something healthy and small every couple of hours. I even accepted the fact that my hair, which I had spent decades straightening, was naturally wavy and looked its best that way. And I didn't just lose the 15 lbs. I gained, I dropped an entire pants size.

Five years later, I feel fitter then I have at any time since I turned 30. More importantly, I found that I don't only look and feel better, my health has improved. My cholesterol levels dropped and I even ran the New York City Marathon this year to celebrate my 55th birthday and raise money for a very deserving charitable organization. And, while turning 50 gave me a shock, now that I am 55 I am happier than ever before. I loved the earlier decades of my life but I rushed through them. I was more insecure then and less happy about how I looked and felt. Like many women, I sought approval from everyone except myself. Now, when I look in the mirror, I see a woman who is brimming with confidence, enthusiasm, and energy. I am happy with who I am and with how I look -- including my crow's feet, which are a part of the story of my life.

So many of us fear aging when we should embrace it. But the greatest lesson I learned on my quest for reinvention is we need to feel comfortable in our own skin, whatever age we are. Whether you are 49, or 62, or 75, you need to decide that you are going to be the fittest, healthiest and best looking 49, 62, or 75-year-old there is. For too long, women have been tricked into seeing 50 as the end of the road when, instead, we should be viewing it as the start of a new life, one in which we are truly comfortable with who we are. Instead of retreating from the world, we can embrace our place within it.

Turning 50 did more than save my life. It put me on the path to a new one.

Other articles at Feminist.com by Barbara Hannah Grufferman: