After a rest day, which Greg spent with his family, the Tour entered the Alps. By this time, three of Greg's teammates had abandoned the race. The remaining ADR riders were not strong climbers. This left Greg exposed on the major climbs of stage 16, a vulnerability that the other contenders exploited by taking turns attacking him. As the wearer of the maillot jaune, Greg had to answer each new assault, and he did so successfully, finishing the stage with Delgado and 13 seconds ahead of Fignon to increase his overall lead on the Frenchman to 53 seconds. Afterward, Greg spoke openly to reporters for the first time about the possibility of winning the Tour.
"If I have another good day tomorrow," he allowed, "I'd say I was in a strong position to win."
Alas, he did not have another good day. Greg cracked on the final climb of stage 17, hitting a wall on the fabled switchbacks of L'Alpe d'Huez. Delgado and Fignon pedaled away to steal 69 seconds from the American. The yellow jersey belonged once again to Fignon. In stage 18, the new leader dropped Greg and Delgado on the approach to another summit finish, padding his lead by 24 seconds.
The mountains had taught Greg that, despite his high hopes, he was not quite as strong as he'd been when he won the Tour in 1986, nor—as he would confess after his retirement—would he ever be. He was riding with 30 shotgun pellets in his body, after all. What's more, he was up against two past Tour winners who'd been caught doping and perhaps were cheating still. If Greg was to beat them, his mind would have to find a way to do more with less—to become stronger to the same degree that his body was weaker.
There was one more mountain stage left to survive. Greg knew that he could not afford to lose any more time to Fignon, or all hope of overtaking him in the final showdown of stage 21 would be gone. Fignon, Delgado, and Greg showed all their cards in stage 19, a 125km race from Villard de Lans to Aix les Bains that passed over three major climbs. The three rivals formed a "royal breakaway" with the fourthand seventh-place riders in the General Classification, leaving the rest of the field far behind as they traded attacks. Greg won the stage in a sprint with Fignon. He recovered no time, but gained a moral victory.
Stage 20 was flat and relatively easy, leaving the overall rankings unaffected. It ended at L'Isle d'Abeau, where the competitors boarded a train bound for Versailles, site of the start of stage 21. The following afternoon, Greg would have one last chance to make up 50 seconds on Fignon. If he fell short in the 24.5-km individual time trial—and if he did, it would likely be by a few ticks—he would be crushed. He was no longer the same man who had said he would be happy to crack the top 20.
Despite the daunting challenge he faced, Greg was his usual congenial self during the train ride to Versailles, chatting casually with journalists the whole way. Meanwhile, Fignon, also true to form, cursed and spat at a Spanish camera crew that tried to approach him. Perhaps both men felt, in their heart of hearts, that what seemed impossible was not.
A 24.5-km cycling time trial is an exercise in pacing. So are all races that last longer than 30 seconds. In races that last less than 30 seconds, competitors go all-out, pedaling, striding, or stroking at absolute maximum intensity from start to finish. They hold nothing back and utilize their full physical capacity. In races that last longer than 30 seconds, competitors do hold back. They pedal, stride, or stroke at less than maximum intensity at all points of the race except perhaps the very end. Instead of going all-out, they maintain the highest intensity they feel capable of sustaining through the full race distance.
Why 30 seconds? Because humans cannot sustain maximumintensity exercise longer than about 30 seconds without exceeding the highest level of perceived effort they can tolerate. Athletes are conscious of their effort in shorter races, of course, but because they know their suffering will end quickly they do not use this perception to control their pace, which is constrained only by their physical capacity. But when an athlete starts a race that he knows will last longer than 30 seconds, he holds back just enough that his perceived effort limit is not reached until he is at the finish line. That is the art of pacing.
What happens when an athlete tries to sustain a maximum intensity of exercise longer than 30 seconds? Anna Wittekind of the University of Essex answered this question in a 2009 study published in the British Journal of Sports Medicine. Nine subjects were asked to ride stationary bikes outfitted with power meters as hard as they could for 5 seconds, 15 seconds, 30 seconds, and 45 seconds on separate occasions. When she reviewed the results, Wittekind found that the subjects had generated slightly less power during the first 15 seconds of the 45-second test than they had in the 15-second test. In other words, they had not pedaled as hard as they could at the start of the longest test ride, even though they had been instructed to do so. Instead, they had unconsciously paced themselves.
Wittekind speculated that, on the basis of past experience, the subjects recognized that they could not sustain a true maximal effort for 45 seconds without exceeding their maximum tolerance for perceived effort, so they held back just a little without even realizing it. These results suggest that the limit of maximum perceived effort tolerance is so impenetrable that athletes are not psychologically capable of even trying to sustain a maximum exercise intensity longer than approximately 30 seconds.
The fact that pacing is required to maximize performance in all races lasting longer than half a minute has some interesting implications. A sprinter finishes every race knowing he went as fast as he could (technical errors notwithstanding). Longer races are different. Because it is necessary to hold back to some degree at almost every point in these races, it is impossible for the athlete to know upon finishing whether he might have gone faster—if only by a second or two—if he'd held back just a bit less somewhere along the way.