Complex sentence: He has authored/coauthored 44 editions of nine fitness & wellness college textbooks and since 1990 he has been the most widely read author in this field among colleges and universities in the United States.
Split into simpler sentences: He has authored/coauthored 44 editions of nine fitness & wellness college textbooks. Since 1990, he has been the most widely read author in this field among colleges and universities in the United States.