Steven Fletcher admitted that the Dundee United squad weren't fit enough before the arrival of new manager Jim Goodwin last month.
The club ended a 12-game wait for a win after beating Hibs 2-1 on Sunday.
“We showed that character against Hibs," said Fletcher. "That’s down to the gaffer, he has come in and filled the boys with confidence in the weeks he’s been here. Our fitness levels and standards; everything is higher.
"The gaffer came in and said, ‘listen, you aren’t fit enough’. We knew that, he’s come in given us a mini pre-season, it was good. The boys bought into it straight away, which is half the battle when a new manager is coming in.”