Last week, his 'double' saw Stoke claim a shock win over champions Manchester United.
Hughes said: "All the credit should go to Charlie. He's always had the ability.
"He's doing lots of extra work - and all football-related. It's not about doing laps and laps around the pitch. It's football specific stuff that will make him sharper and make him more durable during games.
"It's helped him and it's part of his working week now.
"Credit to him. He's embraced the extra workload. You get nothing for free in this life, certainly not the football life, so he's put the hours in.
"He will tell you himself, at times he struggled to sustain an impact in matches. I'm not saying he couldn't complete games but his strengths and qualities would wane towards the end of games and I'd have to make changes but that's not the case now.
"He's finishing games as strongly as he's starting them and that's credit to him and the work he's done."