Professional footballers' union FIFPro on Friday called for longer recovery times for top players between matches and when taking long-haul flights, saying current schedules failed to "adequately safeguard health and performance capacity."
FIFPro's call comes in the run-up to the 2018 FIFA World Cup next week, ahead of which many players were called up by national squads despite a mandatory FIFA rest period, the union said.
Most players "are likely to join their club teams soon after the tournament as well," FIFPro added, saying "the reality is that many players are coming under extreme pressure to perform at their best in difficult circumstances."
Between February and April, the union surveyed a total of 543 players "including those with clubs in some of the biggest European leagues of England, France, Germany and Italy."
Of those surveyed, 300 players represented their national teams.
"In many countries across all FIFPro's divisions, the number of matches played is too high," FIFPro concluded in the study, released at its headquarters in Hoofddorp outside Amsterdam.
It found that almost half of national team footballers who played 50 or more matches per season are being too stretched by the current schedule.
It called on FIFA, leagues and clubs to adopt the following minimum requirements "to protect the health" of professional footballers:
-- At least 72 hours to recover between matches and as a general rule, not play more than three matches every two weeks.
-- Extra recovery time after long international flights.
-- A mid-season break of 10 to 14 days.
-- An off-season break of four to six weeks.
"The survey findings enforce the need for federations, leagues and clubs to pay closer attention to player recovery time," FIFPro's chief medical officer Vincent Gouttebarge said.
"It is important, for example that all national team members returning to their clubs after the World Cup in Russia are given enough time to fully recuperate," Gouttebarge added.