Tokyo - Quick turnarounds of as little as four days at the Rugby World Cup are stretching the squads of established nations and making life especially hard for lesser teams unused to the punishing physicality of top-class rugby.
The five-team pool system makes some short gaps between games inevitable but also gives teams extended lay-offs of as many as 10 days, creating a stop-start schedule.
Unlike in previous World Cups, all teams are under the same scheduling conditions, but the impact of playing two games in four days is being felt most keenly by the smaller countries with less strength in depth.
Minnows Russia opened the tournament with a brave but energy-sapping loss against hosts Japan, visibly tiring in the second half. But four days later, they had to face the physically imposing Samoans, who were playing their first game.
After a disappointing and low-energy 34-9 loss, Russia coach Lyn Jones pointed the finger at the scheduling - suggesting he had not had enough time to prepare his players.
"The short turnaround has affected us tactically and mentally... it's hurt us. We needed more time to prepare," said Jones.
"We played a World Cup final on Friday night and we were just trying to regather - the motivation and focus and concentration on the game was the biggest challenge," fumed the Welshman.
The so-called Tier One nations have the luxury of rotating their players in the knowledge that even a second-string side should have too much firepower for some of their pool opponents.
South Africa, for example, made 13 changes from the team that played New Zealand for their next match against Namibia, while England changed 10 for their second game against USA.
But wholesale changes carry risks for teams outside the very elite - just ask Fiji. The Pacific islanders swapped 12 players for their match against unfancied Uruguay, who played a blinder and recorded the tournament's first shock.
Four days earlier, Fiji had themselves threatened an upset against Australia. Coach John McKee also admitted the short turnaround had caused difficulties.
"For us, obviously with the short turnaround, though it isn't an excuse, it is a challenge," admitted the coach.
Players are used to longer periods of rest between matches in professional club rugby and have had to adjust rapidly. As French forward Arthur Iturria said: "Two matches in four days, no one has really experienced that except at an U20 World Cup."
Ireland fly-half Jack Carty described it as a "unique" situation as his team is used to six or seven-day gaps. His head coach Joe Schmidt has voiced "frustration" at the impact on his injury-hit squad.
The flip-side of the short turnaround - again unavoidable given the five-team pool -- is the lengthy lay-off. New Zealand had 10 days off after the South Africa match and went to a hot springs resort.
France also find themselves with an 10-day gap, a situation Iturria described as "a bit strange. It came as a bit of an abrupt halt after how things were previously... we came to play".
Les Bleus then find themselves facing Tonga and then 'Le Crunch' against England in quick succession - the latter match potentially deciding the fate of Pool C.
Thibault Giroud, in charge of getting the French in top physical shape, admitted: "It will be tough for the boys that play both those games."
It is "impossible at this level" for any player to last the full 80 minutes twice in four days, said Giroud.
Despite the occasional grumble, many teams faced a similar challenge at the 2015 World Cup and are managing as best they can with a 31-man squad.
England coach Eddie Jones told the BBC his team had done a "fair bit of homework" surrounding the tight turnaround, including trialling a four-day gap in Japan last autumn.
And some players take a more philosophical view.
"You cut out the training and it's just the fun part, which is the game," joked All Black forward Scott Barrett.