It can fit into those categories, but it can also fit into the calisthenics (e.g. pushups, situps, pullups, jumping jacks), heavy, vigorous effort, mild stretching, stretching, hatha yoga, teaching aerobic exercise class, weight lifting (free weight, nautilus or universal)
vigorous effort categpries as well. The TRX is so diverse in it's applications, that it's impossible to categorize it in just one way. Fitness Anywhere has already developed a group fitness class using the TRX, a flexibility dvd, and with Todd Durkin, a sports performance workout as well. So depending on what kind of workout you need that day, your classification of the TRX workout will change.
Jeff Boyer, CSCS