This book set includes "Sports Management and Sports Humanities", "Physical Activity, Exercise, Sedentary Behavior, and Promoting Health", "Sports Performance" and "Sports Injuries and Prevention", focuses on the sport-science topics of active children, active elderly, and elite athletes in order to solve health problems caused by recent drastic decreases in human physical activity and fitness. Waseda University of Japan has a tradition of producing great athletes amongst its graduates, such as Mikio Oda, the first Japanese ever to win an Olympic gold medal. Waseda University strongly supports coaching techniques that embody a practical application of the knowledge gained from the fundamental research findings of sports science. Waseda University also takes pride in providing athletes with medical care that utilizes leading-edge sports medicine, and formulates management strategies that combine all these elements. This approach has led to a strong tradition of sports-based research -- what we like to call "Waseda Sports" -- which has enjoyed an unprecedented level of success. This tradition was enhanced by the Faculty of Sport Sciences in Waseda University in 2009 when they initiated the Global COE (Center of Excellence) Program, entitled "Sport Sciences for the Promotion of Active Life". The Global COE Program is under the aegis of the Japanese Ministry of Education, Culture, Sports, Science, and Technology; this Ministry supports the development of international centers of education and research excellence. While life expectancy in Japan is the highest in the world, large-scale societal changes here and elsewhere have led to an increase in health problems due to a decrease in activity and physical fitness. In the aging population there has been a deterioration of overall health, much of which can be attributed to inactivity and excess body weight. It is especially troubling that similar problems are increasing among children and are associated with severe physical and mental disabilities. The international scope of the above problems provided the impetus for Waseda University to form the Global COE Program. This effort involved the construction of an international hub of education and research specifically designed to develop and encourage talented researchers to create sports programs that would contribute to an active and vital lifestyle. The program emphasizes the development of specialist knowledge in conjunction with a broad understanding and awareness of the diverse world of sports. One of our goals was to focus not just on improving the individual health of mind and body, but also to develop an understanding of the conditions present in regions and societies that facilitate such improvements in the lifestyle of individuals. The sports sciences have created and are extending an important body of knowledge. It is critical that this information be utilized to produce an active, two-way interaction between the investigators and the active participants of sporting events. In order to provide a focus for developing this reciprocal intercommunication, the Global COE program identified three strategic project themes: (1) Active Children Project, (2) Active Elderly Project, and (3) Elite Athlete Project. The COE Program was proactive in seeking out mature graduate students who were returning to higher education after a period of work, thereby facilitating a meaningful contribution to the formation of academic careers for specialists who were active in the practical domain of sports. Many graduate students from abroad, especially from Asian countries, joined the program and have contributed to our goals via both the creation of academic knowledge and direct participation in the sports relevant to their area of investigation. The formal funding for the Global COE Program came to an end in March 2014, but the projects initiated by the program and the activities of the graduates continue unabated. The accomplishments made during the 5 years of the program have been documented in a series of four books with the overall theme of "Sports Science and an Active Life". We are proud to present this substantial body of research in the following series of books: Vol. 1: Sports Management and Sports Humanities (Kohei Kogiso, Daichi Oshimi, Munehiko Harada, Eds.), Vol. 2: Physical Activity, Exercise, Sedentary Behavior, and Promoting Health (Satomi Oshima, Zhen-Bo Cao, Koichiro Oka, Eds.), Vol. 3: Sports Performance (Tomoyuki Nagami, Jun Tsuchiya, Eds.), and Vol. 4: Sports Injuries and Prevention (Tetsuya Ogawa, Mako Fukano, Toru Fukubayashi, Eds.). The series was written by the dedicated faculty members and young graduate students and postdoctoral researchers under the guidance of investigators who took part in the Global COE program. The series was also contributed to by leading researchers around the world, most of whom belong to Waseda University's research institute or university partners. I appreciate their contributions as well as their participation in the Global COE program. During the 5 years of the program, an international network of individuals and universities doing active research in the area of sports sciences has been established. I expect this network to grow wider and stronger in the future and to contribute to the solution of many of the health problems that plague modern societies. We will all continue to work hard to involve sports activities in the solutions to these problems, and in the process, aid in advancing the sports activities themselves. Finally, I express my appreciation to the editors of each volume, who not only did a fine job of organizing the volumes but also wrote chapters that were important scientific contributions to the overall effort. We would also like to thank the Global COE staff for their efficient work and the kind support they extended to the graduate students. Drs. Larry Crawshaw and Candace S. O'Connor are thanked for their enthusiastic editorial assistance.