epoepo wrote:
Think it was early EPO plus way harder training.
A 2007 study from another Danish group showed that time-to-exhaustion at 80% of VO2max was increased by about 54% after just 4 weeks of EPO. Over the same time period, VO2max (i.e. maximal oxygen transport) increased by just 12.6%.
So while VO2MAX improves and allows faster times and recovery from mileage and workouts, the key thing here is being able to get in 50% more volume at threshold. They were able to do ridiculous amount of threshold training due to EPO training, which made them so fast.
That's also the reason why many people question El Guerrouj, his super-hero workouts and training would kill any clean 3:30 runner after a few days/weeks.