Figure 2. Peak and Average Heart rates of 1st and 2nd referees for each 10 minute spell of games

From

A Pilot Study of the Physiological Demands of Futsal Referees Engaged in International Friendly Matches

D. Dixon

American Journal of Sports Science and Medicine. 2014, 2(3), 103-107 doi:10.12691/ajssm-2-3-7