Phil Taylor vowed to rediscover his best form after picking up his 11th PDC World Darts Championship title.
Taylor won an enthralling final against Kevin Painter in which 'The Power' was forced to recover from 4-1 down before clinching an epic deciding set 6-5.
"I think I dropped a fraction on what I can do," he said after his 7-6 win.
"My 'A-game' is not as consistent as it used to be and I've got to work at it.
It's a sign that I'm getting a little bit older."
But Taylor insisted his appetite for the game had not diminished.
"My target is to win every tournament I enter, and the world championship is extra special," said the 43-year-old, who lost another epic final against John Part 12 months ago.
"I'm going to dedicate myself to getting really fit this year. I'm going to be on the rowing machine, on the treadmill and will also be doing a bit of boxing.
"These young lads are coming through and they've got more energy than me. I can't practice as much as I used to do and it's annoying me. I get tired.
"Yesterday I only practised for 90 minutes whereas other days I practice for three or four hours."
Painter allowed 4-1 and 5-3 leads to slip but said he had no regrets after missing out on his first title at the Circus Tavern.
"To get to the final is great. Obviously I wanted to win but I'll come back another time," he said.
"If I had missed a shot at a double to win, then I would have been in a bit of mess. But I just didn't get a shot, so there you go."