New Wales fitness coach Andrew Hore has revealed Wales players will have to work on their anaerobic fitness and leg strength.
The 30-year-old, who worked with Wales coach Steve Hansen at Canterbury, has been putting players through their paces with a series of physical tests since arriving on Monday.
One of his main roles will be to form close ties with club coaches to establish a structure to improve players' fitness levels.
The Kiwi believes Wales are generally in good shape ahead of next year's World Cup in Australia.
"Wales had a rough time during the Six Nations but have improved during the last few months and recently ran South Africa close.
"If we can start building now and get the structure right this side can grow.
"At the moment only about half of the squad have been tested and we do need to look at anaerobic fitness and leg strength.
"It is too early to judge overall fitness levels but, from what I have seen, there is a huge amount of potential in the side.
"I am testing the lads and the way they train and co-ordinating a plan to improve overall fitness levels.
"I will be looking to forge close relationships with the club trainers and that is the key.
"If we can start working together for the good of the players then we can start getting some good results."
Nearly 40 players were involved in the first Wales Under 18 training session of the season. WRU National Performance Manager Gethin Watts is excited at the potential shown by the group and expects the Regional Under 18 Championship to hone their skills even further.