Funny how nobody seems to actually know what jetlag is.
Travel fatigue comes straight after travel and can take a couple days for full recovery, especially after very many hrs travel.
Jetlag is a slow poison, comes later, weeks later, as you lose sleep because of the timezone jumps and taking time for biological clock to acclimatize/adapt to new day/night routine vs home.
Was why our SR teams traditionally did well 1st/2nd week to fall off the weeks 3rd and 4th and why little impact on NZ/Aus teams with their shorter tours here (not to mention the difference between east to west travel vs west to east).
Heneke Meyer won SR trophies with this understanding, choosing to send the Bulls as late as possible on tour, not as early as possible, to try squeeze 3rd game in before the lag would start to hit.
How rugby somehow oblivious to the reality all these decades of professionalism vs other sports to this day boggles my mind.
The other joke is the nonsense of altitude. Neither Jhb or Pretoria are actually high enough for altitude to impact professional sportsman, its a mental block from amatuer days and the reality is that its about the harshness of the climate in winter in those areas vs the coast that actually hits the Aus and NZ players, its the dryness that causes that burn they describe, a dry, harsh climate not experienced in other tier rugby playing nations.
Aus want to win at Loftus/Ellis Park, they just need to go play some rugby in their backyard, the outback, instead of only along the coast.