The Sweden international has become an important part of Daniel Farke's side since arriving at Leeds, but his preparations for the campaign were disrupted by a hamstring problem.
Gudmundsson did not feature in any of Leeds' opening three matches this season before returning to action and has since played in every fixture.
The 27-year-old completed 90 minutes in Leeds United's goalless draw with Crystal Palace before the international break and is now back with Sweden.
Speaking to Fotbollskanalen, Gudmundsson explained that the transition from an interrupted pre-season into competitive Premier League football had placed additional demands on his body.
"It hasn't been super optimal for me. I went to the back in the pre-season, then it was straight into the Premier League and I started straight away, Brighton away," he said.
"Since then it has gone well, but it's clear that my body has taken a beating."
Gudmundsson said he has noticed that his recovery between matches has taken longer than usual, although he insisted that he is now feeling healthy.
"It takes me a little longer to recover from the matches. But I feel good, there are no problems," he said.
"The pre-season has been the league game and it has taken a little time for the body to get into the rhythm. My body feels good, I'm ready. There's no problem."
His comments come after a period in which his availability was disrupted by injury.
Gudmundsson had also been absent towards the end of last season before representing Sweden at the World Cup and joining Leeds on their pre-season tour of the United States.
His return has since provided Farke with a regular option at left-back.
Gudmundsson joined Leeds from Lille in the summer of 2025 in a deal worth £10m and has quickly established himself within Farke's system.
Although he has only registered one assist as a Leeds player, he has regularly offered an attacking threat in the final third.
His next potential milestone will come against Arsenal on October 10. If selected, the match would mark his 40th competitive appearance for Leeds across all competitions.
The defender's return has therefore provided some continuity after a difficult period with his fitness.
Gudmundsson's latest comments suggest that while the physical demands of the campaign have been noticeable, he believes he is now through the worst of the issue and ready to continue playing regularly for Leeds.
He remains on international duty with Sweden before returning to club football, with Leeds preparing for the next stage of their Premier League campaign.