Well I found at
http://www.thesportjournal.org/sport...l14no1/lin.asp
Hetzler et al (1989) pointed out that excellent martial players should have the characteristics of very good physical ability, high speed and great strength, blood lactate ranging from 1.51-3.23 mol/100 ml, and blood pH value decreasing from 7.39 to 7.34 mg/dl.
Is there a way to tell if that's linear?