France coach Bernard Laporte insists his choice of players for the World Cup in 2007 will be determined by their physical fitness.
Over 50 players were summoned to take part in tests in August and early this month while a third series will take place in a few weeks time.
More tests will be carried out on the squad during the autumn before France face Australia on November 5 in Marseille, Canada on November 12 in Nantes, Tonga on November 19 in Toulouse and finally South Africa a week later at the Stade de France.
''The physical side is extremely important in my eyes,'' said Laporte.
''Our example are the three southern hemisphere nations (Australia, New Zealand and South Africa) as well as England in the north.
''If we want to be competitive at the highest level we must be capable of challenging our rivals in terms of intensity and ability to repeat our efforts for 80 full minutes.''
France travelled to the southern hemisphere in June and July, and were dealt some harsh lessons, losing 27-13 to South Africa and 37-31 to Australia.
''The best in terms of endurance, speed and strength are the teams in the southern hemisphere and in June we took a lot of young players with us so that they could realise that," Laporte added.
''They saw how huge the physical intensity was on a pitch. In Brisbane seven of my guys had cramps. They understood fast.
''That's why those who do not obtain the minimum results required during those physical tests will not be considered competitive for the World Cup.
''The tests will reveal who can come or not. The results of the tests carried in August will be given to me in the next few days and I can't wait to see them.''
Laporte is confident that good physical preparation allied with France's intelligent game can help Les Bleus lift the much-coveted trophy on home soil in less than two years time.
''I know we will be a success,'' he told L'Equipe.
''The most important thing is that in two years time, when we start to play our first match, we feel we have no regrets about our preparation, that we have done what we had to do.
''But the players must take their responsibilities, be motivated, stop watching the others win and fight.
''Winning the World Cup is a magnificent challenge in a player's life.
''A career lasts 10 years but in this case, we are talking about being world champions.
England's preparations for the Autumn International series were potentially dealt a further blow as Maro Itoje was forced to undergo an x-ray after Saracens' European victory over Scarlets on Saturday night.