"I used to be able to do that when I was your age."

It's a phrase you've undoubtedly heard countless times. Heck, many of you have probably uttered a similar line more times than you'd like to admit.

The aging process can be a hard thing to accept. Our bodies make it easier to store fat as we start to lose muscle. Aches and pains that didn't exist 10 years ago occur on a frequent basis.

But it doesn't have to be that way. We're all going to go down someday, but why go down without a fight? With the right training approach, your athletic prime could be in front of you, rather than a speck in the rear-view mirror.

"We've seen research on every age group, from children to men and women in their 90s, and it's clear that you can get stronger at any age," says Lou Schuler, co-author of the new book The New Rules of Lifting for Life.

"That's pretty well-established. What's less well known is that strength is directly correlated to longevity. It almost doesn't matter what type of strength is being measured -- abs, thighs, grip. The strongest people live the longest. So no matter what age you are, being even a little stronger is always better.

"The great thing about strength training is that it addresses most of the major problems that sneak up on us as we get older. The average man or woman will lose about 1 percent of their muscle mass per year, starting in middle age. With muscle goes a lot of stuff we rarely think about -- the thickness and strength of our tendons and ligaments, the size of our bones, the number of muscle fibers and nerves we can call on when we need them."

But don't blindly dash off to the gym just yet in your newfound quest to be the oldest living person. You have to train intelligently; focusing on stability and mobility in the areas you need it most, and total body strength. Strength that comes from lifting relatively heavy weights -- that means you, ladies -- and for the guys, total-body workouts that don't involve 15 different sets of arm exercises.

"Middle-aged and older women think their bones will shatter if they pick up a weight that's heavier than their purse. There's nothing stranger than seeing a woman do a bench press or bent-over row with a dumbbell that's smaller than her forearm," Schuler says.

"Then you have the guy with a 40-inch waist who comes into the gym and spends the first half-hour working on his arms. Those are the only exercises he can do with weights that seem manly enough for him. First of all, what a total freaking waste of time. Here's a guy with a body that, more than anything, needs exercise. It needs to move. And what's he doing? He's sitting on a bench, trying to move nothing but his elbow joints."

We need that stability most in our midsections -- namely our abdominals and lower back -- which are abused daily when we sit in our cars, at our desks, and in front of the television. We need the mobility in areas like our hips and shoulders, which also suffer greatly during our prolonged periods of sitting down. And what's the best antidote for sitting down? Standing up -- and Schuler's co-author Alwyn Cosgrove incorporates that premise frequently.

"Sitting for hours at a time is probably the most dangerous thing we do on a daily basis," Schuler says. "But when people go to the gym, young or old, what do they do? They sit. They sit on recumbent bikes, they sit down to do cable rows and lat pulldowns, they sit on benches to do shoulder presses. In between sets, they sit some more.

"In Alwyn's workouts, you don't sit. If you're going to do a lat pulldown, you're either kneeling or standing. Same with a cable row. It's a great exercise when you stand up to do it. You have to brace the muscles in your core to maintain your balance and posture. Not only does that make it tougher, it keeps you on your feet."

And it may make you the last one standing.

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