How to retire if you're going to live to 100

Firefighter free falls into retirement
Firefighter free falls into retirement

Maybe 70 really is the new 60.

More Americans are living longer, healthier lives. While that's great news, it also means that our retirement isn't going to look quite like our parents' generation.

It's time to rethink the traditional retirement, write London Business School professors Lynda Gratton and Andrew Scott in their new book "The 100-Year Life."

Life expectancy increases by two or three years every decade, according to data cited in the book. At least half of Americans born in the 1960s can expect to live into their early 90s, and the majority of children born today can expect to live 104.

Graduating from school, working, and then retiring in three distinct periods of life isn't going to cut it anymore. We may not be able to afford retiring completely at 65, but we also might not want to stay in the same 9-to-5 gig for an extra 10 years.

Instead, the researchers propose a multi-stage life that may involve a number of different jobs, and transitioning in and out of the workforce more than once.

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Some Baby Boomers are already embracing this different kind of retirement. Former C-Suite executive Julie Hill left her last CEO job about 13 years ago, but she's still working and has no plans to stop.

"I don't believe in retiring, just morphing. And I hope to morph into my 100th year," Hill said.

She's never followed the traditional three-stage life, instead moving in and out of jobs -- from teaching to the construction, real estate, and finance industries -- and founding several businesses of her own.

Hill, who just turned 70, now sits on two corporate boards and five non-profit boards. And she and her son have discussed starting a business together, eventually.

It was a gradual transition into the role of board executive. She joined her first board in 1994 and was able to use her connections to spring into new roles.

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Many people don't think about what they'll do in retirement until it happens, Scott said in an interview.

The book aims to change that. And while we all know we need to be growing our nest eggs, here are some things that you can do to prepare for a long and happy retirement that don't have anything to do with saving more money.

Keep learning.

Keeping up with the new tech tools of the trade will help you remain in the workforce. Given the rapid pace of technological advances, what you learn early on in life might not be relevant in the last quarter of your 100-year life, the books says.

Hill says that her son, who is 31, and his friends keep her young and up-to-date on how businesses can use technology. She currently sits on the advisory board of the Center for Digital Transformation at the University of California at Irvine, which advises companies on how to stay competitive in the digital economy.

Invest in your health.

"The multi-stage 100-year life is simply not possible with poor health, and the consequences, both financial and non-financial, can be dramatic," write Gratton and Scott.

So pay attention to what you eat, how much you eat and exercise, as well as your mental health.

Spend time with family, friends, and coworkers.

It's easy to see why it's important to keep up a professional network of former and current colleagues. It was the network Hill built over her career that has helped her land several board seats.

But the authors of the book also refer to what they call a "Regenerative Community" consisting of a group of close friends that keep you sane and happy. They're a posse of people who know you across different parts of your life and they likely share some of your interests. These friendships are harder to keep, but extremely helpful in making sure you feel happy, fulfilled, motivated and positive.

Learn how to adapt.

If a longer life brings more stages, it's going to be super important to handle those transitions with ease. Some will be forced upon you -- maybe the company you work for closes or your skills become technologically obsolete. Others you'll have to initiate yourself, like returning to school or starting your own company.

The book offers two big tips to help you through it. First, know yourself. In the past, people often identified themselves based on what they did for work. Now, more people are crafting their own identity and path. Second, be open to new experiences.

Hill said her move out of the role of CEO went so well because she thought a lot about what she had learned that she could bring to her new positions.

"I feel so fortunate to have had a wonderful career, but I knew it was time to move on when the day-to-day was starting to feel confining," she said.