Long time lurker of this site, all year round. I never post because I do not have much to contribute. But on this topic I do know a little. I am from norway and I was an active xc skiier in one of Norways best clubs from childhood till I was 20. I know many of the best norwegian skiiers on a personal level. Also my fathers circle of friends contains many people who work with the norwegian xc team. I personally do not believe that the norwegians ever doped, at least not the entire team. But ofc that is just my opinion and I am not here to debate the doping, just to share some information.
Ive been skiing all my life. I was never on the national team or ever in consideration for it, but I have skiied with and against many of the best norwegians and even beaten some in competition. But clearly I am and never was anywhere near as well conditioned as they are. But I have skied a ton and I have skied with some of the best equipment available. I think a lot of you underestimate how crucial good skis are. The difference between good and amazing skies is huge. In my experience this difference escalates with altitude too. I had a two month stay in Boulder Colorado and at the altitudes there I just died when I had bad skis. It is not nearly that significant when skiing at near sea level around Oslo. Of course my experience, not a scientific fact (but everyone I talk to who has experience with this have the same opinion).
I skied with a guy who has skied for the national team and still to this day competes for them. He was (probably still is) considered one of the best in Norway at preparing skis and I had the fortune of having him prepare skis for me a lot. the skis he prepared vs the ones that my club helped me prepare was quite significant. And this is one of Norways best clubs.
The Norwegian team that was sent to Sochi is not our best team. Some of the skiiers should definatly be there, but others should not. There were better performing skiiers. But there are a lot of politics inside the team, the standards required for those who ski for private teams are much higher than those who ski for the national team. A hint here could be looking at the results from the norwegian championship just prior to sotchi. So I would think some who are there simply arent peaking formwise.
The womans team. As you may be aware of Astrid Jacobsens brother died during the olympics. The media has not reported it, but it was suicide. He was supposedly recently romantically involved with Therese Johaug. This is likely to have impacted the girls a lot.
I am not saying there never was or there is no doping in the norwegian team. I just wanted to emphasise that regardless of doping the equipment in skiing makes a huge difference. its not like any other sport I competed activly in (with the exception of sailing where if you count the boat as equipment the details can make huuuuge differences). Between the age of 6 and 20-22 I have been doing pretty much anything I could get my hands on activly: Soccer, Downhill, cycling, long distance running, bandy (scandinavian+russian soccer on ice with with sticks and small ball thing), sailing and ski jumping.
I know nothing about the golden era of the 90s when I was still young, only what my dad told me (as I mentioned earlier he has many friends who are insiders int he norwegian xc team and other wintersport things). He says he never heard anything about the xc team, but that he is confident Johan Olav Koss was doped. Anyway let me tell you one thing here. I have childhood friend who was much better than me at skiing. My childhood friend skied activly untill he was 23. Like many other norwegians he skied as a college athelete in the US while taking his education. He is an amazing skier and his brother skis professionally and has posted some great results (winning professional circuit races). I believe my friend was more of a talent than his brother, but he never had ambition to be a professional. for the last 3 years we shared an apartment in Oslo and spent almost every day together, even on vacations. he has finished his education and works a fulltime job with a lot of extra hours. He still trains a lot and skis every opportunity he has, but never in competition. The guy doesnt take supplements outside of vitamin pills. I know he can follow his brother who has won races on the professional circuit when training and he himself beleives he could beat him in competition. I have seen him train with nationalteam skiers and the gap between them and him is not big, if there even is a gap at all. He is not unique, we have a ton of good skiers who either lack the ambition or are just slightly not good enough for the national team. The two skiers that I know fairly well on the national team never had a jump in performance. I skied with them before they went pro and if anything their performances have been slightly worse or more inconsistant since they got on the national team. If its doping in the current national team then it is not widespread. And in fact a few of our biggest talents in xc skiing the last 7-8 years had very significant drops in performance after they joined the national team, but seem to now to have regained their form on private teams. Simen Østensen is a good example.
TL;DR Doping or not, the main problem in Sotchi is definatly skis.