Career
Tregaro was a prospective high jumper, who placed 10th in the final of the high jump at the 1996 World Junior Championships. His coach was Viljo Nousiainen. Nousiainen died in 1999.
This left Tregaro and the young triple jumper Christian Olsson without a coach.
This led to Yannick"s decision to begin coaching, his first athlete being the young Olsson. This would go on to become a highly successful partnership.
Tregaro coached Olsson to a gold medal in the 2003 World Championships in Athletics held in Paris leading to Olsson winning the Waterford Crystal European Athlete of the Year Trophy for 2003. In 2004, Tregaro coached Olsson to a gold medal in the Triple Jump at the Athens Olympics.
Earlier that year, Olsson equalled world indoor record in winning a gold medal at the 2004 World Indoor Championships in Athletics.
Bergqvist tore her Achilles tendon in July 2004, making her ineligible for the Athens Olympics.