The 23-year-old had experienced a number of injury problems before the Scot arrived at the club in summer 2012.
However, a different training regime has now seen Delph become one of the first-team regulars at Villa Park.
"When I originally came back from injury I wasn't training every day and for someone like me I think I have to train every day," he told the Birmingham Mail.
"When Paul Lambert came, I thought I would have been training twice a week. But he was like 'no chance - you're training every day'. He got the medical team to push me on. I don't think I've missed a training session since he's been here.
"He got me back training every day. We've had good fitness coaches throughout my time here. I've taken bits from every one of them and managed to just do my strength work and be consistent with that. It seems to be working."
Delph joined Villa from Leeds United in 2009.