⊙ RANGE Once upon a time, these physical phitness phiends plagued only the (otherwise idle) rich. Their exclusive haunts were then-restricted Athletic Clubs, the gymnasiums of well-endowed universities, and elite health spas; so it was commonly believed that the creatures’ earthly mission was to tempt and taunt the inbred and overfed into working up the only honest sweats of their lives. Lately, however, members of the middle class, and even people with jobs, have begun to break out in sneakers and head bands and can be seen staggering and hyperventilating through the dawn-lit streets, the whole world their treadmill, jowls flushed, eyes blank, obviously bewitched and utterly in the power of some sinister supernatural force—the Sweatsylphs.

◐ HABITS Sweatsylphs feed on human ergs, units of energy released by burning calories. (Among their favorite meals are scrambled ergs, ergs benedict, and erg rolls.) As their miserable mortal victims trot, bend, squat, run, jump, clean and jerk, dive and paddle, haul and crawl in order to grow slim, Sweatsylphs hover above them, chuckling and growing ever more plump and happy. Sweatsylphs discourage our interest in team sports—after all, fullbacks and outfielders sometimes get a chance to stand around, enjoying themselves — and encourage us to go “one on one,” in games where personal shame and hostility drive us to heights of excessive activity—or, better yet, to “compete only with ourselves,” in ligament-straining, lung-busting, mindless orgies of exhibitionistic exertion. To the Sweatsylph, the only sight sweeter than a squash raquet is a running track a sixteenth of a mile in circumference.

★ HISTORY Sweatsylphs are Greek and, like all Greek Sylphs, were notoriously sylphish about their sylph-improvement programs. The first of them were nourished by the smoke of the earliest Olympic flame and by the acrid fumes arising from the field below, where oiled and naked youths struggled to heave a pie plate for distance while barbarians were breaking down the gates. In America mortals tended to avoid physical exercise, exertion, or activity of any kind—hence the popularity of the industrial revolution, spectator sports, televised spectator sports, and then the epidemic of video games. Things were looking bad for the sweat-starved Sweatsylphs. But a desperate public relations campaign, waged with the help of their fellow wicked sprites, the West Ghost and Elf Alpha, has convinced us all that we will be flabby and unloved unless we start running twenty miles a day, fueled only by turnip juice and our mantra. So we run and grow thinner and grimmer, and the Sweatsylphs are fat and sassy again. SPOTTER’S

TIPS Look for a Sweatsylph where a yacht owner buys a rowing machine or drives five hundred miles in search of the perfect jogging suit, and when the funeral of a tennis court cardiac-arrest victim is attended by plump survivors, all bravely fighting back their smiles.