Hook said: "There's a lot of competition at fly-half but it's now time for me to step out of the development stage and do it for real.
"I've been working hard and got huge gains from doing weights, speed and fitness work. It's the strongest I've ever felt and I'm really happy.
"At the Ospreys we've been pulling trucks and flipping tractor tyres during pre-season which was good fun. Our new fitness coaches Alex Lawson and Mike McGurn have been great and we're being monitored all the time. The fitness work has really benefited us."
Hook has found himself bowing to the experience of British Lion Jones for the coveted number ten jersey under the tenure of Warren Gatland.
But the 23-year-old showed his versitility at full-back on Wales' summer tour against the Springboks, when Jones retained his place, and Hook says that fighting for his place in the side is perfect motivation.
"Competition between Stephen and myself is nothing new. It's been there for the last few years. But I only played 18 minutes at fly-half in South Africa and now I need to impress.
"What I do at regional level will count for Wales selection and the Ospreys have some huge games early in the season. So my aim is to send a message to Warren by producing some good performances. I really want to start against South Africa on November 8."
Wales face all three southern hemisphere giants - South Africa, Australia and New Zealand - as well as Canada this November. And 27-cap Hook believes Wales can claim a major scalp.
He added: "We've got to take confidence from the Grand Slam and the way we matched South Africa in the second Test on tour. So we know we're not a million miles away from success against them."