First in a scheduled series under the auspices of The Physician and Sportsmedicine magazine, this highly technical training guide will be of most use for advanced, competitive cross-country skiers. Dr. Hixson--Director, U.S. Nordic Ski Team Medical Supervisory Team--describes how Olympic racers train, and how these programs can be adapted for the reader's use; but his remarks are tailored to serious skiers who have ""read all the books""--there is no detailed discussion of technique, equipment, or waxing. Covering recent advances in cross-country skiing, Hixson explains the biomechanical determinations used to analyze performance (velocity = stride length x stride rate--all affected by the mechanics of the kick, glide, and ""pole implantation"" phases). The weight of the book, however, is on training. A year-round conditioning program consists of dry-land conditioning, transition to snow, and skiing; the availability of devices such as roller skis, and exercise and weight machines, is assumed. Some general discussion of relaxation techniques and nutrition could be useful for the recreational skier, but most of this (""if a skier with a Max VO of 80 milliliters per kilogram can tap 80% of his Max VO for 30 kilometers, his projected time will be about 98 minutes. . ."") is for the serious competitive skier with access to special equipment and an experienced trainer.