Klich played 90 league games on the trot for Leeds over the last two years and only got a rest toward the end of the season, when promotion to the Premier League was confirmed.
From being on the chopping block to being an ever-present player in the Leeds starting eleven, Klich has come a long way and he has received great praise for the fitness he has shown over two years.
But Klich admits that it did not happen overnight and he has been working on his endurance over a number of years.
He also feels with experience comes the knowledge of how to remain fit and added that Marcelo Bielsa’s regime over the last two years has also contributed to his success.
Klich told Polish magazine Pilka Nozna: “It just doesn’t come out of nowhere.
“I have been building my endurance for years, in Germany and then in the Netherlands.
“There was also experience and awareness of working on one’s fitness and plus very good physical preparation in the last two seasons at Leeds.”
He stressed that playing regularly has also helped his body to get used to the workload needed to play at a high level.
Asked if pre-season is more difficult in England compared to other countries, the midfielder said: “No, they are just as difficult as anywhere.
“By playing regularly, the body gets used to the workload. Over time, it becomes easier to play a large number of games throughout the season.”
Klich will now have to cope with the demands of the Premier League in the upcoming season.