No football fan needs to be reminded that a match lasts 90 minutes or slightly longer. But while that hour and a half is plenty of time for a player to make his mark, precious few are capable of remaining effective for the whole duration.
It takes a special kind of energy and focus to maintain standards from start to finish - so imagine France's fortune to boast two such livewires in Florian Thauvin and Lucas Digne. That the dynamic duo have two lungs like everybody else is almost a minor miracle.
The industrious pair have excelled for their country at the FIFA U-20 World Cup Turkey 2013, helping Les Bleuets advance to the quarter-finals, where they will face Uzbekistan. France's marathon is far from over yet, which means Thauvin and Digne – winger and left-back respectively – will have to keep their foot on the pedal for a little while longer. "It's true that since we play on the wing, we can't allow ourselves the slightest easing-off and we're constantly working hard," Lille defender Digne explained to FIFA.com.
"My first priority is to defend well, but I also have to do everything I can to help out offensively. That's the job of a modern full-back. The coach gives me his instructions, but there's also an element of intuition, knowing when you can get forward and when to hold back so as not to unbalance the team."
Playing in a more advanced role, Thauvin faces the opposite conundrum. Like a good wing partner, he quickly expanded on his team-mate's theme. "It's true that a striker stays up front and a centre-back stays central to do his job, but we need to have the legs to do both," added the 20-year-old, who will continue to perfect his understanding with Digne next term after swapping Bastia for Lille.
"The instructions to fall back and help defensively are very important, giving you a certain responsibility. Obviously, to keep going at this rhythm every three days means that how you recover is crucial," he added. Digne could hardly agree more: "In general, I sleep really well after a match."
France have never won this tournament and we realise we have what it takes to do it, this year more than any other.
The defender no doubt enjoyed particularly sweet dreams after France's superb 4-1 victory against Turkey in the last 16, with many predicting a nightmare for Les Bleuets in front of the host nation's passionate supporters.
"We played a perfect match," said Digne. "Although we had a little trouble in the group stage, we're already in the quarter-finals, so we can be satisfied. And I get the impression that we're getting better and better." Turkey would surely attest to that as well, with the home side having possibly expected a less polished display from opponents who drew 1-1 against USA and lost 2-1 to Spain in Group A.
"What changed between that game and the ones before it? It was a decisive match and we had no room for error," explained Thauvin. "This was a benchmark game for us. Everything worked and we put all our heart into pulling off the best performance possible." Perhaps, but it would only be fair to point out that the two friends have been putting their heart into their football for quite some time now, both in terms of their extraordinary work rate down the left and at key stages in their careers.
Thauvin nearly had no career to speak of, in fact, his progress having been interrupted by physical problems. "I suffered a serious back injury when I was younger and I almost stopped playing," he said, recalling his early days at Grenoble.
Thankfully, he was able to make a full recovery. "When you dream of having a professional career, that's a huge blow, but I kept on working towards becoming a professional. Since then, I've been aware that everything can change quickly and that gives me the strength to fight for every ball."
Digne has so far managed to steer clear of any such setbacks – at least on a personal level. Instead, he derives motivation from the example of his older brother, a former Lille youth academy member who brought his sibling on board with Les Dogues but had to quit the game after injury.
"He had a lot of quality, but he got injured and never regained his previous level and never got the chance to break into the professional squad," said Digne. "I know that he's now living his dream through me, and that gives me the strength to never admit defeat."
The two southpaws will therefore be raring to go against Uzbekistan as they look to take another step closer to the final in Istanbul. Having come this far, neither player will be content with anything short of lifting the trophy.
"Our goal has been clear since the start," explained Thauvin, a huge admirer of Lionel Messi and Ronaldinho but who feels closer in style to Angel Di Maria. "France have never won this tournament and we realise we have what it takes to do it, this year more than any other."
Few would dispute that given the pedigree of the teams still involved, with Brazil and Argentina having failed to even qualify and Colombia, Mexico and Portugal all suffering early exits. In their absence, Les Bleuets now look to be one of the hot favourites alongside Spain.
"Of course, the fact that certain big teams aren't here makes the tournament more open," said Digne, who pinpoints Philipp Lahm as the model full-back. "Either way, whenever you start a tournament you go there to win it, whichever teams are there at the starting line."
As for the finishing line, any athlete will tell you that the competitor who crosses first tends to be the one with the most juice left in his or her legs. Able to draw upon the resources of tireless wing pair Digne and Thauvin, France could yet be leaving everyone in their dust.