Liverpool's return to non-contact training "felt like the first day at school", says manager Jurgen Klopp.
The Premier League leaders worked in small groups at their Melwood training ground on Wednesday for the first time since the coronavirus lockdown.
The English top flight hopes to resume in June, with 92 fixtures left to play, having been suspended since 13 March.
"I woke up even earlier than usual and then I realised it was my first day," Klopp told Liverpool's website.
"It felt like the first day at school - for me, it was 46 years ago, but it must have been similar.
"I dressed myself in my uniform again - and for the right reason, for going to training."
The easing of government restrictions have allowed players to train in small groups in staggered sessions, with all 20 clubs unanimously agreeing to stage one of the return-to-training protocols at Monday's "Project Restart" meeting.
As well as training in groups of no more than five, sessions must last no longer than 75 minutes for each player. Social distancing must be adhered to.
Liverpool are 25 points clear at the top of the table, with nine games to play, and need just two more wins to secure their first Premier League title.
The league had previously identified 12 June for matches to possibly start again, but there is now an expectation this will need to be pushed back.
Klopp said he was "really happy" to see his players again and that they were all in "good spirits" and "good shape".
"We don't know exactly how long we have, but we have some time to prepare the rest of this season and already the next season, because I don't think there will be a massive break between the two," he said.
"It's a pre-season for us. We don't know how long and we will not have test games or friendlies.
"Maybe we can organise it between us when we are allowed to, but it will not be the same like in other pre-seasons."
Klopp said he was glad his players had had a "real rest" during nine weeks off in lockdown, as opposed to two or three weeks of holiday per year.
However, he added: "Of course, you cannot rest when you are worried about the situation in the world, not in the same way like you do on a proper holiday."
Defender Adrian Mariappa and two staff members at Watford and Burnley assistant manager Ian Woan are among six positive Premier League tests for coronavirus revealed on Tuesday.
A total of 748 players and staff were tested in the first round of twice-weekly testing as part of the return-to-training measures.
Official protocols sent to players and managers last week, and obtained by the BBC, revealed corner flags, balls, cones, goalposts and even playing surfaces will be disinfected after each training session.
Klopp said the the protocols are "brilliant" and that he felt his side were able to train in a "very, very safe place".
He added: "Then hopefully for all of us we will get good news because that always would mean the development was in the right direction for the whole country and then for the league as well."