Journal of Applied Physiology, Vol 71, Issue 1 125-130, Copyright © 1991 by American Physiological Society
Cold exposure during military operations: effects on anaerobic performance
A. C. Hackney, J. M. Shaw, J. A. Hodgdon, J. T. Coyne and D. L. Kelleher
Department of Physical Education, Exercise, and Sport Science, University of North Carolina, Chapel Hill 27599.
This study examined the effects of military field operations (MFO) under
different environmental conditions on anaerobic performance. US Marines
were tested in the field under the following conditions: 1) noncold
environment (NC; n = 30, 10-32 degrees C) and 2) cold environment (CO; n =
32, -2 to -22 degrees C). Subjects performed 30-s Wingate tests (WIN) pre-
and immediately post-MFO to assess anaerobic performance. The MFO consisted
of approximately 4.5 days of combat training maneuvers while carrying field
equipment (packs and weapon, approximately 25 kg). WIN measures obtained
were absolute and relative mean power (MP), 5-s peak power (PP), and
fatigue index (% decline). Significant main effects (P less than 0.01) were
observed for time (pre-post MFO). Reductions occurred in absolute MP [651.8
+/- 30.3 to 616.4 +/- 28.5 (SE) W] and PP (897.8 +/- 41.6 to 857.0 +/- 39.1
W); however, no effect on fatigue index was seen. Significant interaction
effects (P less than 0.05) were observed in relative measures. Reductions
(pre-post) in MP (NC = 8.64 +/- 0.16 to 8.37 +/- 0.14 W/kg; CO = 8.91 +/-
0.26 to 8.04 +/- 0.15 W/kg) and PP (NC = 11.80 +/- 0.24 to 11.61 +/- 0.33
W/kg; CO = 12.23 +/- 0.35 to 11.20 +/- 0.19 W/kg) were greater under CO
than NC conditions. These changes were found despite significant (P less
than 0.05) but comparable pre-post weight reductions in both CO and NC
conditions.(ABSTRACT TRUNCATED AT 250 WORDS)
