By Jay Gormley & Jason Allen, CBS 11 News

GRAPEVINE (CBSDFW.COM) – At 51-years-old, David Ball is still running marathons. The Grapevine resident says a healthy life style is the key to success.

Ball says he plans to live a long time, because frankly, he feels he’ll need to work well into his 70s before he can retire.

“I started thinking the other day that I really better watch what I eat even more so and really focus on staying healthy and fit,” said Ball. “I need to be able to take care of things around the house and in my life.”

Many people in their 40s and 50s are feeling the painful equation. When the market drops like it did Monday, so do their 401ks. It seems the only thing going up these days is the retirement age.

“It worries me for sure,” said Judy Hendry of Richardson.

Judy and her husband Steve face an uphill battle. Steve is a realtor working in a housing market that has seen better times.

“It’s been pretty tough the last three years; hoping and praying that things would continue at a steady pace,” said the 53-year-old. “Naturally, the real estate business is kind of like a rollercoaster.”

Judy is a physical therapist at a retire community. She contributes to a 401k, but is taking a wait and don’t look at it attitude. “I don’t think we’ll have enough to feel comfortable retiring. You just can’t count on it, she said”

People in their 40s and 50s are being advised to ride it out over the long haul. But with their 60s just around the corner, the long haul isn’t so long anymore.

With the market drop, there’s also the prospect of higher interest rates for homebuyers.

“We’re looking at calling the realtor and saying we need to move on this, like, ASAP,” said Keven Markham, a Frisco homebuyer.

Experts say some homebuyers and sellers may need to move quickly, because if the interest rates increase they may be unable to afford the home of their dreams.

But for those with more long-term plans, they may not need to panic. There have been no significant changes in the overall economy since last week.

“Obviously, it had a big impact on the stock market, but that might also be a recognition that the economy’s much weaker than we thought it was and therefore the stock markets are reacting to that as much as anything,” said William Crowder, a University of Texas at Arlington professor.