An Analysis of Thermoregulatory Sweating and Heat Balance in American Football Linemen and Backs

• Main Author: Deren, Tomasz
• Other Authors: Jay, Oliver
• Language: en
• Published: Université d'Ottawa / University of Ottawa 2012
• Subjects: Thermoregulation; Core Temperature; Football; Sweating; Morphology; Training Camp; Backs; Linemen; Heat Stress; Heat Stroke; Convection
• Online Access: http://hdl.handle.net/10393/20644; http://dx.doi.org/10.20381/ruor-5348

This thesis examined why NCAA Division 1 American football “linemen” experience greater heat strain than “backs” during summer training camps. In study #1, exercise at a heat production of 350 W/m2 in a hot environment (Tdb:32.4±1.0ºC; Twb:26.3±0.6ºC) resulted in greater local sweating on the upper body (head, arm, shoulder and chest; all <0.05) and a greater core temperature (P=0.033) in linemen despite a ~25% lower heat production per unit mass (L:6.0±0.5 W/kg; B:8.2±0.8 W/kg). In study #2, greater convective and evaporative heat transfer coefficients (P<0.05) were found in backs during live summer training camp drills, but these did not lead to a greater dry heat transfer or evaporative capacity. However, the maximum metabolic rate per unit mass was lower in linemen due to differences surface area-to-mass ratio. In conclusion, the greater heat strain previously reported in linemen likely arises, in part, from differences in sweating efficiency and body morphology.