This season, a long-time Texas high school football coach is coaching a German squad.

The incident taught him that he needed to alter his coaching method.

Randy Jackson has taken over as offensive coach of the Potsdam Royals of the German Football League.

He chastised his players during video conferencing when their performances are not good.

Jackson coached high school football in Texas for 30 years.

He anticipated that adult European men would respond well to the same strict approach he had used with American teenagers.

However, at the Royals' first spring practise last April, Jackson's players couldn't go through a normal round of conditioning drills without running to the sideline to vomit.

That's when he realised he needed to find another approach to motivate them. 

Athletes from all over the world and at all levels of competition are rebelling against traditional coaching tactics.