Sir Alex Ferguson says Manchester United's summer tour of the Far East was one reason why they ended last season without a trophy.
United took on Thailand, Singapore and Malaysia last July.
They then went on to lose the Charity Shield to Liverpool before enduring a disastrous start to the Premiership campaign.
We always analyse these Far East trips and they're not the best preparation
"We got to the Charity Shield and you could see the difference in fitness as they were ahead of us in terms of games," Ferguson said.
"The players were playing catch-up in terms of fitness at the start of the season.
"We always analyse these Far East trips and they're not the best preparation.
"The games are played at a certain pace - not leisurely, but the opposition aren't the best and there's no real edge to it.
"The players can't move. They're stuck in the hotel all the time. They go out of the door and there are thousands of fans there."
But Ferguson admitted such tours were important in promoting United in the Far East.
"From a fans' point of view and the fact that the Far East is an emerging market for United, it has to be done," he said.
"We have to do it, but we really need to look at condensing it, making it an in-and-out situation."
United strolled to the Premier League title in 2000 even though they toured the Far East and Australia that pre-season and Liverpool also visited the Far East last summer.
United took on Thailand, Singapore and Malaysia last July.
They then went on to lose the Charity Shield to Liverpool before enduring a disastrous start to the Premiership campaign.
We always analyse these Far East trips and they're not the best preparation
"We got to the Charity Shield and you could see the difference in fitness as they were ahead of us in terms of games," Ferguson said.
"The players were playing catch-up in terms of fitness at the start of the season.
"We always analyse these Far East trips and they're not the best preparation.
"The games are played at a certain pace - not leisurely, but the opposition aren't the best and there's no real edge to it.
"The players can't move. They're stuck in the hotel all the time. They go out of the door and there are thousands of fans there."
But Ferguson admitted such tours were important in promoting United in the Far East.
"From a fans' point of view and the fact that the Far East is an emerging market for United, it has to be done," he said.
"We have to do it, but we really need to look at condensing it, making it an in-and-out situation."
United strolled to the Premier League title in 2000 even though they toured the Far East and Australia that pre-season and Liverpool also visited the Far East last summer.