Tennan's area of passion and expertise was volleyball, and he contributed to its development throughout the world as a technical leader for both FISU and the International Volleyball Federation (FIVB).

He began working for FISU in 1983 in his home country of Canada at the Summer World University Games in Edmonton.

Until 2015, he was chair of the FISU volleyball international Technical Committee, supervising the FISU volleyball and, since 2000, beach volleyball competitions.

As head coach of the University of Saskatchewan's women programme, he guided the team to the Canada West Conference Championship seven times and the Canadian University Championships on three occasions.

An author of books, papers, films, and conference presentations, Tennant brought innovative ideas to the sport and initiated a true volleyball culture change at both the national and international levels.

"Mark will always be remembered for his numerous personal qualities, his dedication, his love of sport and his great professionalism," wrote FISU Acting President Leonz Eder and secretary general and chief executive Éric Saintrond in their condolence letter to Tennant’s family.

"He was such a wonderful person, and we feel lucky to have had the opportunity to know him, work with him and share with him his passion for volleyball."