Gov. Rick Perry says that fatigue associated with his recent back surgery is to blame for stumbles in some of his first debates, despite his team's repeated denials to reporters for months that the procedure had any impact on the candidate's performance.

"If there's one thing I could have changed in my campaign I would have moved that surgery I had the first of July back to January," Perry said Tuesday on Sean Hannity's radio program. "I didn't realize it was going to have as big an impact and frankly I didn't know the impact it was having on me from the standpoint of just being fatigued and it showed up in the first few debates."

Perry went on to use his oft-cited long distance runs as a sign of his recovery. "I have never felt better and I think you saw a glimpse of what you can expect out of me as we go forward in that last debate we had in Iowa."

The Texas governor, who had an advanced spinal fusion using adult stem cells this summer, admitted in an interview on Sunday with the Des Moines Register that the surgery had caused a delay in getting "back in the game" mentally and physically.

In the interview, Perry also took shots at the two top polling candidates in the race, repeating his slams of Mitt Romney's $10,000 bet and tying Newt GIngrich to Washington corruption.

"Mitt's from Wall Street. Newt's from Washington," Perry said after criticizing both for once supporting the individual mandate for health insurance. (He also cited several of the commonly used interview transcripts in which Romney talks about the successes of the mandate in Massachusetts.)

Without mentioning Gingrich by name, Perry also took aim at Washington lobbyists.

"We also need to know at the definition of lobbying. A lot of these members of the legislature, members of Congress, they become - quote - "consultants" to trade and lobbying organizations without actually registering as lobbyists. But you and I both know you're hiding behind a definition."

"Let's quit being politically correct here and call it what it is," he said. "You're trying to influence people, you're getting paid for it. Americans know that's lobbying."