DEAR DR. DONOHUE: I weigh 245 pounds and am 5 feet 7 inches tall. I used to weigh 275 pounds. At that time, I took a stress test because my chest hurt when I exercised. My heart is healthy. For the past five months I have been exercising, and I feel great and have lost 30 pounds. I exercise at least four times a week for one and a half to two hours, doing cardio exercise for 30 minutes and weightlifting for an hour. Everyone says I look fat. Why do people judge me on looks? Can’t I be considered fit? – E.D.

ANSWER: Body weight isn’t the sole criterion of fitness. You have proof through a stress test that your heart is healthy. That’s evidence of a most important facet of health.

Your height and weight put you in the overweight category, but height-weight charts are notoriously imprecise in estimating health. Body mass index – BMI – a number obtained by dividing weight by height, is a better estimate. Your BMI also puts you into the overweight class, but BMIs are inaccurate for the very muscular individual. Football players, weightlifters and wrestlers have BMIs that indicate that they’re overweight, but their weight is mostly muscle and bone, and that’s not unhealthy weight. Fat is unhealthy weight.

How are you to determine how much of your weight is fat and how much is muscle and bone? One way is by measuring the width of skin folds, pinches of skin and fat that are accurately measured with calipers. Some health clubs and some doctors take such measurements. Other ways are impractical but are more precise. Underwater weighing compares weight in land with weight in water, and from those measurements the proportion of body fat can be determined. X-rays, ultrasound, electrical transmission and scans can also provide an accurate assessment of body fat, but these methods are not obtainable for most. If you want a reliable, quick and inexpensive estimate, find someone who has calipers and can measure your skin folds.

DEAR DR. DONOHUE: I coach junior-varsity football. In the past three years, I have had three boys have a tooth knocked out. I am trying to prepare myself to handle this situation if it ever again arises. Can you help? – H.J.

ANSWER: A knocked-out tooth can be saved if quick action is taken. Don’t scrub or rub the tooth. Ligament tissue clings to it, and preserving that tissue is necessary to re-establish its mooring in the tooth socket. Rinse it with tap water. Keep the tooth moist. Reposition in the mouth if that’s possible. If it isn’t, put it in a container with cold milk or sterile saltwater. Transport solutions to preserve teeth are commercially available. One is Save-A-Tooth, and it would be good to keep some vials of it on hand at all games and practices.

Get the injured player to a dentist promptly. Make arrangements with a dentist to be on call at home during all games and in the office during practices.

Are your players wearing mouth guards? They should be.

DEAR DR. DONOHUE: I read your article on the person who did nonstop sit-ups and how that affected his kidneys. I am a personal trainer and have used this method in my own program for 20 years. How do I know if my kidneys have been damaged? What’s my next step? – C.T.

ANSWER: The person was a young man who went overboard doing sit-ups, like hundreds of them, when he wasn’t used to doing any exercise. The intense, unaccustomed exercise caused his abdominal muscles to break down – rhabdomyolysis. The breakdown products cause kidney shutdown. He recovered fully from the incident. You would know if you ever suffered rhabdomyolysis. It’s terribly painful, and urine turns dark brown. If you do lots of sit-ups and are none the worse for wear, you can continue to do so.

DEAR DR. DONOHUE: My husband suffers from cluster headaches. They started in May 1998, went away, came back in October 2002 and lasted for three months. At that time a doctor prescribed oxygen, which helped relieve the pain and the length of time the headaches lasted. Since then, they have returned in November 2005, May 2007 and November 2007, lasting from six weeks to three months. My husband says there’s nothing new for them. Do you know of anything? – C.H.

ANSWER: Cluster headaches behave exactly as your husband’s do. They come in “clusters,” with many headaches a day, and they recur for days, weeks or months and then disappear for long spans. Invariably, they return. A cluster headache is a terrible headache with pain unimaginable to those who have never suffered one. They are one-sided headaches that usually center around the eye. The eye waters, and the nostril on the same side often drips. Pain lasts for 15 minutes to two hours and often wakens a person from sleep. The pain is so awful that an affected person has to get up and pace frantically until the headache leaves.

For treatment of a cluster headache, oxygen works well. It’s inhaled, so it gets into the blood quickly. I don’t know if your husband has ever tried sumatriptan, a migraine medicine. It’s available in a self-injectable dispenser and in a nasal spray. Both forms, like oxygen, get into the blood quickly for fast action. Zolmitriptan, another migraine medicine, also comes as a nasal spray and can bring rapid relief.

Preventive medicines for cluster headaches keep them from recurring so often. Verapamil, a heart blood pressure medicine, is one example. Lithium is another. So is the short-term use of prednisone.

The headache booklet describes the more common kinds of headache, like tension and migraine. Readers can order a copy by writing: Dr. Donohue – No. 901, Box 536475, Orlando, FL 32853-6475. Enclose a check or money order (no cash) for $4.75 U.S./$6 Can. with the recipient’s printed name and address. Please allow four weeks for delivery.

Dr. Donohue regrets that he is unable to answer individual letters, but he will incorporate them in his column whenever possible. Readers may write him or request an order form of available health newsletters at P.O. Box 536475, Orlando, FL 32853-6475. Readers may also order health newsletters from www.rbmamall.com