Coach Clemens began his rowing career in Germany in the mid-1970's winning several gold medals at the German Scholastic and Junior Championships in the single, as well as, doubles and quads. In 1978 and 1979, Clemens won the Junior Single event at the Thames Head Race in England. He was part of the German Junior National Team and trained with world champion sculler, Peter Micheal Kolbe. In 1979, Clemens medaled gold for Germany at an International Youth Regatta in Villach, Austria. More recently, Clemens won his race in the Masters single at the World Masters Regatta in Varese, Italy, in 2013.
He began coaching for the Ruderverein Wandsbek, Hamburg, in 1981 and completed his Coaching-B license from the German Rowing Association in 1983.
He holds coaching certificates from the German Rowing Association (Deutscher Ruderverband Level B) and the U.S. Rowing Association (Level 2). Annually, he attends the Joy of Sculling Coaches Conference and the USRowing Advanced Coaches Conference to further educate himself as a coach.