Now he aims to keep Cardiff on the front foot in the Heineken Cup against Castres Olympique.
"I'm the fastest I've ever been, the heaviest and probably the leanest, so I'm really happy with the way things are going in the gym," said Halfpenny.
"I've been working hard on my speed and footwork and now I want to show it on the pitch."
Cardiff stuttered to an unconvincing 18-17 win over Edinburgh on the opening weekend but Halfpenny reckons his side can call on their previous French experience to kick-start their European campaign at Stade Pierre Antoine.
"It's always hostile in France and the fans try to put you off your game. But that won't affect me. I don't think it can get any more hostile than the Amlin Cup final against Toulon last year in Marseille and we won that game," added Halfpenny.
"French teams are always strong but we're confident. We've won in France before and we can do it again. I'm looking forward to going out there and doing whatever it takes to get the win."
The European clash will serve as a final opportunity for Halfpenny to impress Warren Gatland with the Wales boss due to name his autumn squad next week. Wales will take on Australia, South Africa, New Zealand and Fiji as they look to build on a promising performance in the second Test defeat to the All Blacks in June.
"I'm really looking forward to the autumn internationals.
"There's nothing better than playing against the top three teams in the world and I'm looking forward to getting stuck into them.
"If we can get some results, our confidence will go through the roof."