The Wales team management - increasingly happy with the high fitness levels of their players - invited the media to witness the VO2 testing which gauges the amount of oxygen each individual player can consume in the space of a minute.
The gruelling test involves running at full tilt on a treadmill for about 10 minutes and breathing into a scuba-style face-mask for the final 60 seconds of the run, at which point the treadmill is switched to its steady incline setting.
The players have to keep going until heart monitors reach a certain level, then the masks go on, which means the fitter you are the longer the test takes.
'The test measures how much oxygen the body can consume in one minute,' said Wales fitness trainer Andrew Hore.
'Basically the more you can consume the fitter you are, aerobically, and this is the most direct way to measure capacity.
'We have also done a 3km run test which does the same thing, but there can be discrepancies with that dependant on individual power and leg speed.
'Someone who gets one result on the 3km run could get significantly better results in this test and this is the one that would give the accurate reading.
'The results enable us to tailor training regimes to the specific needs of individual players.'
A special machine measures the content of oxygen in the air the players breathe out and blood tests immediately after the run determine how much oxygen has been taken in by the players.
Hore will receive results from the fortnight of testing tomorrow and he is expecting to be pleased by the standards the players have been setting.