Estil finished the 2005/06 season in ninth place in the FIS World Cup standings, 456 points behind winner Tobias Angerer.

Estil finished fourth in the distance, 420 points behind Angerer, and again did not compete in the sprints.

In the 50 km race he won in a time of 2:30:10.1,[2] beating Anders Aukland by 0.7 seconds, and Odd-Bjørn Hjelmeset came third making it a Norwegian sweep.

In the relay, Norway (Hjelmeset, Estil, biathlete Lars Berger, and Tore Ruud Hofstad) won, with Germany second and Russia third.

At the 2007 FIS Nordic World Ski Championships in Sapporo, Estil won only one medal.

He lost the gold at the finish line of the 50 km event to fellow Norwegian Odd-Bjørn Hjelmeset.

However Mühlegg was found guilty of doping and disqualified by the IOC in February 2004, therefore upgrading Estil and Alsgaard to joint gold medalists.

[6] Estil also took part in the 50 km classic, but finished ninth, in a time of 2:10:44.8, 4:22.0 behind winner Mikhail Ivanov of Russia.

[7] At the 2006 Olympics in Turin, Italy, Estil won the silver medal in the men's 15 km + 15 km double pursuit competition despite taking a fall and breaking a ski at the start of the race which put him in last place.

Estil's results mirrored those of the Norwegian cross-country team who failed to win a single Gold medal in Turin, owing to stomach illness and waxing mistakes made by Norway's eight man strong service team.

Estil's Olympic medals include two golds and two silvers.. Estil has a high hemoglobin level, and has received a blood-certificate by the FIS, so that when his blood is tested the maximum hemoglobin allowed to race is 17.5 grams hemoglobin per 100 ml of blood, compared to 17 grams for men and 16 grams per 100 ml for athletes without this certificate.