KneesUp
Guru
Maybe the smoking is the reason for the performance increase?
Altitude training has also become common among endurance athletes, because it has been associated with an increase in performance and in serum hemoglobin and hematocrit levels. However, this response is transient — the physiologic variables return to their baseline soon after the athlete returns to sea level.2 This moderate performance benefit is outweighed by several severe and life-threatening risks, including pulmonary edema,3 cerebral edema4 and severe flatulence.5
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3001541/
While athletes endanger their careers and well-being in attempts to gain small benefits with illicit or inconvenient practices, a legal, nonprescription alternative has been largely ignored by athletes, coaches and exercise physiologists alike. Cigarette smoking has been shown to increase serum hemoglobin and hematocrit levels, increase lung volume and stimulate weight loss — characteristics all known to enhance performance in endurance sports.