Seasonal Differences in Performance of the Ranger School Qualifying Road March

Authors

  • William J Tharion U.S. Army Research Institute of Environmental Medicine (USARIEM)
  • Anthony J Karis U.S. Army Research Institute of Environmental Medicine (USARIEM)
  • Adam W Potter U.S. Army Research Institute of Environmental Medicine (USARIEM)
  • Reed W Hoyt U.S. Army Research Institute of Environmental Medicine (USARIEM)

DOI:

https://doi.org/10.12922/jshp.v2i2.47

Keywords:

Army Ranger School, road march, backpack, military, performance, physiology

Abstract

The U.S. Army Ranger School conducts a 61-day training course several times per year to train soldiers in combat skills.  One of the qualifying tests is a timed road march.  Warmer weather imposes greater thermal strain on the body which in turn compromises endurance performance.  This presents a problem in assessing performance across classes and making the road march fair for all students since some will be doing this event in cold or cool conditions (winter, spring and fall classes), whereas others will be doing it in hot conditions (summer classes).  Purpose: To assess the influence of seasonal differences on road march performance.  Methods: Road march times and per-mile pace were obtained from three Ranger School course classes (total: n = 66; [spring: n = 24, summer: n = 23, and winter: n = 19]).  Road marches were ~19.3 km for the spring and winter marches and ~12.9 km for the summer march.  Heart rates (HRs) and core body temperatures (Tcores) were obtained throughout each march. Weather conditions were spring: air temperatures (Ta): 17.2 to 21.0 °C; relative humidity (% RH): 53 to 75%; summer: Ta: 24.4 to 25.0 °C, RH: 82 to 89%; and winter: Ta:  −4.4 to −6.2 °C, RH: 51 to 60 %.  Results:  The per-mile pace of the spring class (15:35 + 0:45) [min: sec] was significantly slower (p < 0.05) than the summer class (14:57 + 0:58) or the winter class (14:46 +1:19).  A significant main effect of Tcore was observed by class; with the summer class students exhibiting significantly (p < 0.05) higher Tcore than spring or winter students (spring: 37.7 + 0.4 °C; summer: 38.2 + 0.5 °C; winter: 37.7 + 0.5 °C).  Conclusions: The Ranger School’s goal of having equally challenging road marches across classes was not met.  Even with the shorter course, the thermal strain was greatest for summer students, and a greater number of spring class students passed the standard with less than maximum effort.

Author Biography

Adam W Potter, U.S. Army Research Institute of Environmental Medicine (USARIEM)

Adam Potter is the Research Program Coordinator and Deputy Chief of the Biophysics and Biomedical Modeling Division at the United States Army Research Institute of Environmental Medicine (USARIEM). Mr. Potter served on active duty in the U.S. Marine Corps, participating in real-world operations in Kosovo, Iraq, and Liberia. Prior to working at USARIEM, he performed numerous in-patient clinical research trials. He holds a Bachelor of Arts in Psychology from Cambridge College, a Masters of Business Administration and Master of Science in Sports and Health Sciences from American Military University.  Mr. Potter's current research interests include: thermo-physiology and thermoregulation modeling; estimating metabolic cost over complex terrain; exercise dosimetry for early detection of overuse injuries; and biophysics and clothing impacts on human performance.

References

Department of the Army. Army Regulation 600-9, The Army Weight Control Program. Washington, D.C.: Headquarters Department of the Army, 27 November 2006.

Department of the Army and Air Force. Army Regulation TB MED 507 and Air Force Regulation AFPAM 48-152, Heat Stress Control and Heat Casualty Management. Washington, D.C.: Headquarters Department of the Army and Department of the Air Force, 7 March 2003.

Ely MR, Cheuvront SN, Roberts WO, Montain SJ. Impact of weather on marathon-running performance. Med Sci Sports Exerc. 2007; 39(3): 487-493.

Gonzales-Alonzo, J, Teller C, Andersen SL, Jensen FB, Hyldig T, Nielsen B. Influence of body temperature on the development of fatigue during prolonged exercise in the heat. J Appl Physiol, 1999; 86(3):1032-1029.

Goodman DA, Kenefick RW, Cadarette BS, Cheuvront SN. Influence of sensor ingestion timing on consistency of temperature measures. Med Sci Sports Exerc, 2009; 41(3): 597-602.

Jones SB, Knapik JJ, Sharp MA, Darakjy S, Jones BH. The validity of self-reported physical fitness test scores. Mil Med, 2007; 172(2): 115-120.

Knapik JJ, Ang P, Meiselman H, Johnson W, Kirk J, Bensel C, Hanlon W. Soldier performance and strenuous road marching: influence of load mass and load distribution. Mil Med, 1997; 162(1): 62-67.

Knapik J, Staab J, Bahrke M, Reynolds K, Vogel J, O’Connor J. Soldier performance and mood states following a strenuous road march. Mil Med, 1991; 156(4): 197-200.

Moore RJ, Friedl KE, Kramer TR, Martinez-Lopez LE, Hoyt RW, Tulley RE, DeLany JP, Askew EW, Vogel JA Changes in Soldier Nutritional Status and Immune Function During the Ranger Training Course. Technical Report T13-92. Natick, MA: U.S. Army Research Institute of Environmental Medicine, 1992.

Sawka, MN, Latzka WA, Montain SJ, Cadarette BS, Kolka MA, Kraning KK, Gonzalez RR. Physiologic tolerance to uncompensable heat: intermittent exercise, field vs. laboratory. Med Sci Sports Exerc, 2001; 33(3): 422-430.

Simpson RJ, Gray SC, Florida-James GD. Physiological variables and performance markers of serving soldiers from two “elite” units of the British Army. J Sport Sci, 2004; 24(6): 597-604.

Tharion WJ, Lieberman HR, Montain SJ, Young AJ, Baker-Fulco CJ, DeLany JP, Hoyt RW. Energy requirements of military personnel. Appetite, 2005; 44: 47-65.

Tharion WJ, Karis AJ, Potter AW. Mood states of U.S. Army Ranger students associated with a competitive road march. J Sport Hum Perform, 2013; 1(3): 1-9.

Weather Underground Web site [Internet]. Atlanta, GA: Weather Underground; [accessed 2013 Feb 3] Available from http:/www.wunderground.com/history/airport/KCSG

Wilkinson DM, Carter JM, Richmond VL, Blacker SD, Rayson MP. The effect of cool water ingestion on gastrointestinal pill temperature. Med Sci Sports Exerc, 2008; 40(3): 523-528

Downloads

Published

2014-11-01

How to Cite

Tharion, W. J., Karis, A. J., Potter, A. W., & Hoyt, R. W. (2014). Seasonal Differences in Performance of the Ranger School Qualifying Road March. Journal of Sport and Human Performance, 2(2). https://doi.org/10.12922/jshp.v2i2.47

Issue

Vol. 2 No. 2 (2014): Journal of Sport and Human Performance

Section

Original Research Articles

License

Authors who publish with this journal agree to the following terms:

    1. Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
    2. Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.
    3. Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access).