I look like death. By the end of the week we all do. We're drained There must be a reason we put ourselves through this. He reaches for his heavy bag. The reason is, if you want something as badly as we want to dance, you'll do anything to get it. Anything at all.

THE WORDS ARE THOSE of a member of the New York City Ballet, in Joseph H. Mazo's Dance Is A Contact Sport. Amid the current wave of books on dance (the publishing industry is finally beginning to catch up with the box offices) Mazo's book and another recent entry, Franklin Stevens' Dance As Life stand out for their frank and balanced portrayals of daily life in America's two leading ballet companies, both of which also number among the half-dozen or so greatest companies in he world. For those who have studied dance, and wondered what the professional world would have been like, for those who go occasionally to dance recitals and want a glimpse backstage, or for those who are simply curious as to what besides medical school and Sun Myung Moon still commands the kind of zeal quoted above, Mazo and Stevens offer some answers.

Mazo does so with particular flair. Without being too gossipy, his brash, kaleidoscopic view of the NYCB's Spring 1973 season is as thorough as a documentary. Mazo captured what would never have been spoken before a camera. His style is chatty: George Balanchine, founder and ballet master of the Company and probably the world's finest choreographer, is "Mr.B.", after the fashion of the dancers; choreographer Jerome Robbins ("the resident monster") is "Jerry."

Choosing to focus on the company as a whole rather than on the leading dancers, Mazo describes the gruelling company class which begins each day, the hectic rehearsals, the technical preparation of the state, the performances, the union disputes, the endless financial problems. Mazo also recounts some of the tricks of the trade-how an emergency cast change can prove workable, for instance: "standing in the wings, you can hear dancers whispering instructions to their partners, smiling more widely than ever so the audience won't see their lips moving."

But perhaps more than anything else, it is the account of the details of the dancers' world which makes Mazo's book fascinating. He has faithfully recorded where the Company members live (West 69th Street), where they eat (O'Neal's), what they do in their spare time (movies and crossword puzzles), their pre-performance rituals (a touch on the shoulder and a good-luck wish of "merde"), even the contents of the candy machine in the dancers' lounge. What would otherwise be trivialities accumulate to form a tantalizing mosaic of a way of life which demands the dedication of a monastery and the loyalty of a fuedal fiefdom.

The reader is always aware of the author's presence, but for the most part he is an engaging companion, an outsider allowed fleetingly on the inside of a closed world, and unabashed in love with it. Unfortunately, enthusiasm can on occasion become condescension, most annoyingly with regard to the female dancers ("she's so sweet you could sip her through a straw"), but such lapses of taste are rare. More often, Mazo brings fragments of the life sharply into focus with his knack for daring imagery ("feet flash out and back like darting fish"), and what could have been either an uncritical catalogue or a collection of gossip succeeds instead in being both thorough and sparkling.

Whatever their problems, the dancers who come to life in the pages of Mazo's book have indisputably "made it." Although Dance As Life is subtitled "A Season With American Ballet Theatre," one of its strengths is its often poignant portrayal of those who couldn't make it, or won't make it, and one who chose not to: the author himself, who gave up a promising dance career to become a writer. It is this which makes Stevens' book unique, and at times intensely personal: "What am I doing in these street clothes ...a civilian and a foreigner, when I can feel every stretch, contraction, and effort of the muscles...in my own body?" Stevens laces his writing with colorful anecdotes from his own background, and the authority of experience blends with nostalgia.

Despite the subtitle, only slightly more than half the book deals with the daily life of ABT, and this section is actually a more superficial treatment of behind-the-scenes life than Mazo's. Stevens' strength is the concise, graceful way he fleshes out the background of a professional dancer's world, the grounds of experience one doesn't see on a daily basis but which are no less a part of each performance than the rehearsals. There is an unusually perceptive discussion of partnering, for instance-presumably the fruit of Stevens' own experience-a vivid and painful account of an audition for ABT's School, since such trials are unavoidably the stepping-stones of any career in dance, and a dexterous, if occasionally incoherent, whirlwind summary of dance history.

The New York City Ballet is essentially the vehicle for the colossal creativity of George Balanchine, while American Ballet Theatre prides itself on its eclecticism. Yet the enclosed worlds of the two companies have far more similarities than differences. A ballet audience sees an art of grace and discipline and complexity, but it is the strength of both these books to illuminate the extraordinary difficulty of the life behind the art.

There are the obvious physical hardships: the basic problem of forcing the body to learn a whole new language of movement, the constant battle with fatigue, the endless and inevitable series of injuries. But what is perhaps more insidious are the psychological burdens. Since most careers end at forty or so, every dancer is in a race with time, and as Stevens points out, the working years are full of "quiet, savage, heartbreaking competition"--and jealousy. Most dancers are not soloists, and for this majority there are the added burdens of low pay (a first-year NYCB corps member earns some $6,000 and anonymity.

It becomes almost impossible to develop involvement in, much less prepare for, any life outside the sealed box of rehearsal hall and stage, and this breeds an almost unbearable amount of tension. The physical and psychological stress-the two are not necessarily distinguishable-can be overwhelming. As one dancer remarks to Mazo, "I doubt that anyone can stay in this place and be healthy."

Why, then, do dancers choose to be dancers? Neither book provides a clear-cut answer. Certainly it is not for the elusive goals of fame or monetary reward. Yet both books offer hints, glimpses of something beyond the regimentation and the sweat and the pain. For while dance is all those things, it is also, in Stevens' words, "a reaching for some kind of ecstasy."