On the theory that even a little exercise is better than none, a kind of sneaky little booklet has been published that is candid designed to seduce the most determined lazybones into a few minutes of e-e-easy exercise a day.

Called "Feel Better," the pamphlet is published by Blue Cross and Blue Shield, whose vested interest in preventive health is self-evident.

And it doesn't even say "exercise" in the title.

With advice from such fitness mavens as Richard Keelor of the President's Council on Physical Fitness and Sports, Dr. Donald Vickery, president of the Center for Consumer Health Education, the booklet's authors outline a program of spoon-fed exerci-oops -- activity that may not get you into the Boston marathon (if you're reading this, probably the last place you want to be anyway), but could toughen up some of that flab.

The booklet also has a built-in way to make time for it.

"Mild activity," writes Gary Frost, San Diego behavioral psychologist, "will result in your need for less sleep. That means you won't notice getting up maybe 15 minutes early for some activity. In fact, you'll feel better."

The booklet's free by writing or calling the Blue Cross/Blue Shield plan in your area. In the D.C. area: 479-8302, or write to 550 12th St. SW, Washington, D.C. 20024.

Another new book for exercising short of the Boston (or New York of any other) marathon is "Get Moving! Exercises in Later Life," by Olga Bibza Adkins, a former ballerina and now emeritus professor of health and physical education at Miami University, Oxford, Ohio.

Adkins' exercises are designed for those who either cannot or do not care to get up. They all may be done sitting! The book is printed on hard, thick paper which opens from bottom to top, all of which makes it easier for arthritic fingers and aching limbs to get into better shape. It is $3 and may be obtained from the publisher, Scripps Foundation Gerontology Center, Miami University, Oxford, Ohio 45056.

The Journal of the American Medical Association, whose covers are notoriously artsy, are beginning to let art creep in with the double-blind crossover statistics.

Preoccupation with the illness of people in paintings, or of the painters, is not an uncommon hobby of some disgnosticians who seem to be trying to outdo one another in medical cultural erudition. (JAMA has, in fact, been using occasional cover art of paintings by artists with recognizable clinical diseases for some decades, many selected by Dr. John H. Talbott, former JAMA editior.)

One recent JAMA article hypothesized that Peter Paul Rubens, or someone he worked with over a long period of time, had rheumatoid arthritis.

Now it isn't, mind you, just a matter of curiosity that Rubens' St. Anne had a clearly arthritic wrist.

What the modern rheumatologists are saying is that an illness many thought to be recent origin was thriving some 200 years earlier.Listen to this 20th-century description of poor St. Anne's hands in a portrait dated 1626-1630: "Metacarpophalangeal and interphalangeal swelling and hint of ulnar deviation of fingers. . ."

Poor old Vincent Van Gogh had his problems, too, more than Kirk Douglas or Don McLean ever told us. According to Georgetown University Medical Center surgeon Dr. Thomas Lee, all that beautiful bright yellow, all those lovely golden haloes that characterize so much of Van Gogh's work all could have been cause by digitalis intoxication.

Turns out that eagle-eyed Dr. Lee, an artist of sorts himself and an art scholar of some note, spotted a couple of foxglove plants held by Van Gogh's physician in two paintings Van Gogh did of him.

Foxglove, the source of digitalis, was used by 19th-century doctors to treat epilepsy, some form of which, says Dr. Lee, most authorities agree the anguished Dutch artist suffered.

The toxic effects of digitalis, reports Dr. Lee, include "visual changes, hazy, cloudy or yellow vision and red-green perception difficulties. . . ."

Not letting your children cry may give them asthma, reports a doctor in the current issue of Glamour magazine.

Dr. Robert L. Sadoff says in the April issue that "holding back tears tends to keep people from properly expressing their emotions, thereby allowing abnormal or more self-destructive effects." Like asthma. The article also reports that asthma attacks have been known to stop when crying starts.

Bichemical research has produced some evidence that emotional tears contain toxic chemicals which are eliminated when you cry, further confirming the let-it-all-hang-out school of mental research.