DEAR DR. ROACH: I am 69, and I retired from a career in primary care and emergency medicine. I have always been very active and have kept fit with biking, cross-country skiing and hiking. My diet has been basically vegetarian with lots of fish and limited sweets. I have had no chronic problems except for insomnia and nonrestorative sleep. About two years ago, I developed steadily worsening fibromyalgia and chronic fatigue. I have had an extensive evaluation, including cardiac testing, sleep studies, respiratory testing and virtually every lab test in the book. My results have been negative, except for a significantly elevated ANA. I am currently seeing a rheumatologist, but there is no specific treatment available.

My concern is how much I should continue to exercise. Should I push through the aches and fatigue to try to keep up my usual distances and times, or will that actually make me worse? My symptoms vary so much from day to day that it is difficult to ”listen to my body” to see if what I did the previous day has made me better or worse. I hate to see a lifetime of conditioning swirl down the drain. I could use some help. — J.L.

ANSWER: Systemic exertion intolerance disease, also known as chronic fatigue syndrome, is diagnosed in people with a decrease in their level of function, worsening of symptoms after exercise and unrefreshing sleep. Symptoms often are worse when standing up and relieved on lying down, and may cause decreased ability to think or concentrate. Symptoms need to be present for six months or more, and be moderate to severe at least half the time. People who suffer from these symptoms can be frustrated because there isn’t a blood test or X-ray to confirm the diagnosis. There unfortunately still are many people, including physicians, who think this isn’t a ”real” condition. Those of us who have taken care of patients like you understand that this condition, known for centuries, causes great harm to patients (and families).

The answer to your specific question is no: You should not attempt to exercise past the point where your body tells you to stop, as it will indeed make things worse. Although a study showed that people who slowly build up exercise levels have improvement in function, a recent review of the data suggests that far fewer people had a benefit than previously thought. However, several other trials have shown that some exercise is better than no exercise. Everyone agrees, however, that overdoing it is the wrong approach.

DEAR DR. ROACH: I understand that the Food and Drug Administration has approved an artificial cartilage (Cartiva) for arthritis. If worn-out cartilage can be replaced, it should be a real game changer for this disease. Could it become one? — D.

ANSWER: Cartiva is an artificial cartilage implant composed of a synthetic polymer resembling cartilage. So far, the Cartiva surgical implant is for only one joint: the base of the big toe. The data for that procedure look promising. I don’t know if the same technique would work in other joints, such as the knees, but I hope to see future research, as I agree with you that it could be a big advance.

READERS: The booklet on vertigo explains this disruptive condition in detail and outlines its treatment. Readers can order a copy by writing:

Dr. Roach

Book No. 801

628 Virginia Dr.

Orlando, FL 32803

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.

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Dr. Roach regrets that he is unable to answer individual letters, but will incorporate them in the column whenever possible. Readers may email questions to ToYourGoodHealth@med.cornell.edu or request an order form of available health newsletters at 628 Virginia Dr., Orlando, FL 32803. Health newsletters may be ordered from www.rbmamall.com.