Study Period
The playing season in Denmark starts in July or August
and ends in June in the following year. In the 6- to 8-
week preseason period from June to July/August, most
teams are having a vacation for 2 to 3 weeks. The playing
season includes a midseason competition break from
December to March that divides the first and second halves
of the playing season. In this midseason break, most teams
have a vacation for 2 to 3 weeks.
The 10-week intervention program was introduced in
the midseason break because this is the only time of the
year in which this unaccustomed exercise does not conflict
with the competitive season. The injury registration began
when the participating teams started their first training
session in 2008 (January/February) and ended when the
teams ended their last training session in 2008