As your most personal trainer, I'm happy to address all healthy lifestyle concerns. These days, your questions come in mostly via email, but there's nothing like the charm of a handwritten piece of reader mail, delivered to my postal box, punctuated willy-nilly, often written on prison-issue stationery.

Dear Marilynn, Mrs. Preston, Hey, Coach: What does it mean when my knees crackle? What can I do about jiggly underarms? How can I stop chafing between my legs when I run?

To the crackling Mr. C.: Noisy knees are not usually an alarming problem for active people. Knees are complicated joints, with fluids, bones, cartilage, tendons, muscles and ligaments all in attendance, and little room for error. It's normal for them to make sounds. Not snap, but crackle and pop for sure. Severe pain is not normal, so if that' s happening to your knees, you must consult with your medical team and figure out what's going on.

To Amy: Jiggly underarms are a reoccurring theme of this column. No one likes them, and many active people get them, even if they are workout maniacs — strong, athletic and fit.

There are a few things you can do about jiggly underarms, the least of which is cosmetic surgery. I know we live in a Nip & Tuck world, and everyone is free to whack away at the body they were born with, but to me, voluntary surgery, anesthesia, hospital bugs and bills add up to a lot of risks that I'm very hesitant to take. I feel differently about wine.

One of the best ways to prevent or at least postpone underarm jiggle is to exercise in ways that build up your arm muscles, not just your triceps, but your biceps and quadriceps, too.

(Did you catch that? Your quadriceps are in your legs, the big muscles just above your knees. You knew that, right?)

My favorite underarm jiggle fighter is yoga, which is constantly putting you into poses that build strength and define muscles in your upper and lower arms, your shoulders, your back and all over your body, right and left, front and back.

Will a vigorous yoga practice make advanced underarm jiggle disappear? Probably not. But if you really take on the yoga philosophy, you won't care as much.

You can also fight underarm jiggle in the gym, doing mindful dips, flies, push-ups and pull-ups, and dozens of other targeted exercises, and that's good, too. But be warned: Proper form is crucial, and so is knowing which muscles you engage and which muscles you relax. Tricep dips with tense neck muscles could put you in bed for a week.

The theory is simple: The more you grow your arm and shoulder muscle, the less the flesh appears to sag. The truth is a bit more complicated. As we age, underarm skin loses its elasticity, stores fat and loves to go limp. Ditto for chins. You can fight the good fight — stay lean, keep active, lift weights — but at the end of the day, don't be surprised when gravity taketh over.

And that's my final bit of advice to all who suffer from underarm jiggle. Stop suffering. It's under the category of small stuff, and going through your daily life with a sour and negative body image is such an energy drain. Focus on your strengths, not your sags. Arm exercises will improve your situation no matter what, but you can't spot reduce. Strive to be healthy, do what you can, and accept what is.

And finally, the important question from a reader who suffers from chafing between the legs when she runs. Can it be prevented, or is it a matter of losing 20 pounds?

Perhaps both. Jiggly thighs are fleshy thighs, and overall weight loss will help. But that's pie in the sky, for the future. For now, get yourself a simple over-the-counter lubricant — Vaseline is one, Udder Cream is another— and grease up your inner thighs before you start running. If it begins to wear off during your run, carry a tube of lip balm (for thighs), and reapply as necessary. Running in high-performance synthetic fibers that wick away moisture will also help. Avoid running tights with thick seams or zippers — that might add to your aggravation.

Energy Express-O! Hope This Rubs You The Right Way

"To offer no resistance to life is to be in a state of grace, ease and lightness." — Eckhart Tolle

Marilynn Preston — fitness expert, personal trainer and speaker on healthy lifestyle issues — is the creator of Energy Express, the longest-running syndicated fitness column in the country. She welcomes reader questions, which can be sent to MyEnergyExpress@aol.com. To find out more about Preston and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate website at www.creators.com.

COPYRIGHT 2008 ENERGY EXPRESS, LTD.

DISTRIBUTED BY CREATORS SYNDICATE, INC.