I am also a strong advocate against the overwhelming use of sugar in the average diet (including that of athletes). Much of my initial inspiration came from Sami Inkinen (link: fatchancerow.org). He and his wife rowed 2750 miles from California to Hawaii (unassisted) to raise awareness around the dangers of sugar. Another inspirational documentary that I would highly recommend to everyone is Fed Up (2014) (link: imdb.com). The documentary is brief, simple and surprisingly entertaining. WHO (World Health Organization) has also released simple statements and guidelines regarding sugar intake among children and adults.
A new WHO guideline recommends adults and children reduce their daily intake of free sugars to less than 10% of their total energy intake. A further reduction to below 5% or roughly 25 grams (6 teaspoons) per day would provide additional health benefits. (link: who.int)
As a result of these stories, I have excluded sugar from all my training (this includes all power bars and energy drinks) and I mainly use sugar based products during a long distance race when I find it necessary. If anyone has any thoughts on these topics, I would be glad to hear them as well!