Figure 4. Carnosine content of gastrocnemius muscle in male and female active elite runners, according to their best running distance.

All male (n = 22) and female (n = 12) elite runners were ranked according to their best running distance (using the IAAF scoring tables of athletics). The X-axis displays running distance (m) in a logarithmic fashion and the Y-axis shows the carnosine content, expressed in Z-scores. A Y-value of zero corresponds to the average of the male/female reference population. The median Z-score per group is shown and the best sigmoidal fit is presented.