It's always the non-knowledgeable running fans talking about the sudden improvement from Farah. Here's Canova explaining his improvement:
About Mo Farah, the eviolution is not exactly how many of you think.
At the end of October 2009, after Berlin WCh, Mo Farah asked me, when we were in Iten, to help him to become faster. In WCh, with 7 athletes together at the bell, Mo was n. 7, while James Kwalia won bronze behind Kenenisa and Bernard, and Mo was sure to be stronger than Kwalia.
He came Iten withou program, and started to train with my group, with something different that I gave him to do, because his characteristics were not the same of many athletes of my group.
What he started to use, that never had used before, were : short sprint uphill, in order to increase the frequency and to reduce the length of every step, really too long for thinking possible a fast last lap ; couples of lactic distances, one longer one shorter, with short recovery between tests and long recovery between sets (for example, 4-5 times 1200m in 3'03"/3'06", 2' recovery, 300m in 39", wit recovery 6' between every couple ; and lon run that never he did before (for example, one time 30 km in 1h39').
He trained in Iten all winter, I adviced him to look at 10000m (he didn't like the distance), because in my opinion had more chances for a medal in London Olympics in 10000 than in 5000, and we planned to run the first 10 km on road on 31st May 2010, the UK Championships of 10 km in Manchester. He went arriving the day before from Iten, and won with 27'45" beating Kogo.
Five days later, he competed in Marseille in the European Challenge of 10000m on track, and I sent a pacer for helping him (Philemon Limo), who lead till 6800m. After this, Mo went alone winning in 27'28"86, and decided to run in European Ch, both the distances.
He went in altitude in Font Romeau, and trained following my programs till ECh in Barcelona, when he won 5000 and 10000.
The next plan was to try two National Records : 3000m of Moorcroft in Birmingham against Bernard Lagat, and the first under 13' in Zurich.
When I spoke with him, he told me "Forget Birmingham, after Barcelona I didn't have any training, because I had so many appointments with Media that only I went for easy run, once per day".
He ran, if I well remeber, in 7'42", behinf Lagat. Few days later, he ran Zurich, and I was surprised to see him running 12'57" in that condition.
Mo was an Adidas athlete, so I was surprised when I received an email from Steve Magness, who informed me Nike was interested to have Mo with the Company, offering him the opportunity to train in Portland with Salazar's group. Steve asked me some info about what we used in training, and I sent him all the plan we used during the last 9 months.
So, his change was due to a change of training system, at the beginning, and, when in Oregon, at the very high level of professionalism he found in Alberto's group, and at his incredible motivation in training. He absolutely didn't use any substance during the period in Iten, and without any supplement ran 12'57" with a last period of poor training, so I don't see any reason for thinking that, for running 12'53" when in Oregon, with perfect training and a lot of assistance, he need to take some illegal substance.