Comment by mantas

Enduramce athletes go just bellow lactic threshold most of the time. The body is OK to go above threshold, but only for a limited time. The key is to correctly time usage of that above-threshold capability.

I race MTB. Both quick races and long, 100 miles or even 24h solo events. In a quick <3h race, I just go all-out and stay above threshold most of the time. But I try to time my above-threshold usage in long races. In one of the 24h races, the course had a single climb. I was riding everything but that climb bellow threshold. It would have been very hard to stay bellow threshold on it. While it was just a couple minutes effort above threshold.