VLamax estimated

Hello to all.

I’m looking for an explanation of VLamax estimation (as sites like Inscyd, Aerotune, Sentiero… can do). This is a subject I am interested in and have read the Mader and Heck Papers, however, estimating Vlamax without lactate intake is a real mystery to me.

Do you have any information on this subject?

Thanks in advance to all!