"I still feel Alex Zulle is perhaps the most dangerous, even though he is that far behind," the Texan said of his Swiss rival who lost time after crashing in the first week. Faced with six mountains, notably the finish at the Italian ski resort of Sestriere, Armstrong is also determined to stave off a hidden threat.
"I have never been exposed to a media onslaught like this, even when I won the world road race championship. I have to be calm. If I let all this attention get to me, and I don't sleep or eat correctly then physically I will not be the same.
"Yet having the yellow jersey is not the most stressful thing to happen to me," said the American, who in his own words "was a half-way dead man" after cancer two years ago.
He had won the 1993 World Championship and competed for the US Olympic team in 1992 and 1996, and had just signed a two-year contract with Cofidis, when he started feeling sick in October 1996. He felt some soreness "down there." Then he started coughing blood. "This wasn't drops - this was buckets," he said. Headaches, blurred vision, flu-like symptoms and dizziness followed.
Did he think he was going to die? "Sure. I was scared, when they first told me. Of course they told me it was 95 per cent curable - but that's when they catch it early. I knew I had a more advanced case."
Armstrong had surgery to remove his right testicle and brain lesions, then three months of chemotherapy. He was out for the 1997 season, and began his comeback last May.
The Frenchman Christophe Moreau is Armstrong's nearest rival on time, 2 minutes 20 seconds behind, but the specialist climbers can do untold damage.
"They may not win the overall classification, but they will be chasing stage wins," Armstrong said. "The climb to Sestriere is long and demanding, and it will be decisive. We have to keep as many team-mates with us for as long as possible, and not allow anyone to break away. If either of the Alpine stages suits me better it is l'Alpe d'Huez. It will be more selective."
The "serpent" of the Alps tomorrow has 22 bends and its 14 kilometres will be jammed with camper vans, tents, and a capacity audience once estimated at close on 250,000.
Yesterday Armstrong's sponsors, US Postal, announced that they were extending their sponsorship by two years and that their leading light had also signed until the end of 2001.
The American Bobby Julich will be out for a month with fractures of the left elbow and two ribs after his crash in the time trial. Chris Boardman, for his part, is determined to finish this year despite admitting he may be coming to the end of his career.
The 30-year-old Briton is 123rd overall after the first week, 19 minutes behind Armstrong. But after crashing out in both the last two years, Boardman wants to make sure he reaches Paris for the first time.
"That's why I'm here, that's why I have looked after myself during the first week," he said. "I have already identified the hard stages where I have got to dig very deep. Whether I am coming to the end of my career I don't know, but I will just give it my best shot and see what the end result is."
1 L Armstrong (US, US Postal) 33hr 34min 16sec; 2 C Moreau (Fr, Festina) +2min 20sec; 3 A Olano (Sp, ONCE) +2:33; 4 S O'Grady (Aus, Credit Agricole) +3:25; 5 A G Galdeano (Sp, Vitalico Seguros) +4:10; 6 J Voigt (Ger, Credit Agricole) +4:10; 7 L Dufaux (Swit, Saeco) +4:19; 8 A Peron (It, ONCE) +4:22; 9 S Gonzalez (Sp, ONCE) +4:37; 10 D Nardello (It, Mapei) +4:46; 11 J Kirsipuu (Est, Casino) +4:57; 12 A Casero (Sp, Vitalico Seguros) +5:01; 13 P Tonkov (Rus, Mapei) +5:10; 14 M Backstedt (Swe, Credit Agricole) +5:15; 15 L P Rodriguez (Sp, ONCE) +5:17; 16 S Heulot (Fr, La Francaise de Jeux) +5:38; 17 P Savoldelli (It, Saeco) +6:00; 18 K Livingston (US, US Postal) +6:06; 19 S Wesemann (Ger, Telekom) +6:08; 20 E Dekker (Neth, Rabobank) +6:09. Selected: 37 R Virenque (Fr, Polti) +7:21; 97 M Boogerd (Neth, Rabobank) +16:01; 123 C Boardman (GB, Credit Agricole) +19:04. Points category: 1 Kirsipuu 215; 2 Cipollini 182; 3 O'Grady 181. Mountains category: 1 M Piccoli (It, Lampre) 37pts; 2 L Brochard (Fr, Festina) 15; 3 L Lebreton (Fr, Big Mat) 13.Reuse content