In 1973, Rainer Martens, a kinesiology professor at the University of Illinois, attended the North American Society for the Psychology of Sport and Physical Activity Conference, and he wanted to publish the proceedings. Finding no interested publishers, he and his wife, Marilyn, recognized a need and created Human Kinetics in 1974. Three years later, HK hired its first employee and published Physiology of Fitness, still a leading professional fitness book in its sixth edition.

The leading publishers of the day saw a decline in physical education and began abandoning the field. Rainer saw an opportunity and decided, with only limited resources, to fill the niche.

HK grew by reinvesting earnings and expanding into new areas such as coaching education. In 1984, HK began publishing educational resources for the YMCA, doubling the company’s sales. The following year, Rainer left the university to work full-time at HK. That same year, HK acquired Leisure Press, a sport and fitness trade publisher. As sales and opportunities grew through the years, Rainer launched International Offices in Canada, the United Kingdom, Australia, and New Zealand.

By 1990, HK had sales of $6 million and 80 employees. HK expanded beyond print to publish video, software, and online education products by reinvesting earnings in new technology. At the start of the new millennium, HK had grown to over $20 million in sales and approximately 250 employees. In 2005, Rainer Martens sold Human Kinetics to his employees as part of an Employee Stock Ownership Plan. Today, worldwide revenues top $37 million and, with 320 employees, HK publishes more products—including books, journals, videos and courses—than any other publisher serving physical activity disciplines.