The camp sits at 2,400 metres and has, by Mensah's count, produced nine athletes who reached a major final and one who won it. It has never had a written training plan.
"It is written," he says, tapping his head, and then, because he can see the question coming: "That is the problem. I know."
The knowledge nobody wrote down
Mensah is one of eighty-two coaches in the first cohort of Kenya's certification programme — most of them over fifty, several with medallists on their record, none of whom held a certificate before this year.
The programme's syllabus was built by interviewing the cohort rather than importing a European curriculum, a decision its funders initially resisted and its designers now describe as the only reason it worked.
"They came with a book from Germany," Mensah says. "Good book. For Germany. Here the athlete runs to the camp before the session because there is no bus. That is in nobody's book, and it is the most important thing about the session."
What certification changed, and what it did not
The certificate has changed his life in exactly one way: grant conditions. Funding that requires certified staff was, until this year, closed to the camp. It is now open.
It has changed nothing about the training, which he says plainly and slightly wearily, as though he has been asked to justify a thing that does not need justifying.
What worries him is the layer below: the camp coaches working unpaid, who cannot afford to lose a week to a course however cheap the course is.
"I could take the week. I am old and I have a house. The young ones cannot. So the certificate goes to the people who least needed it."
The export problem
Mensah has watched his own methods appear in European training literature, uncredited, for two decades. He is less bitter about it than everyone who asks him about it expects.
"They took the intervals. They could not take the hill or the altitude or the boy who has run eleven kilometres to get here. They took the part that travels."
He is more interested in a different question, one the certification programme has forced into the open: what happens to thirty years of undocumented practice when the person holding it stops.
"That is why I sat in the classroom. Not for me. So that somebody writes it down while I am still here to correct it."