• Robin Orr Tactical Research Unit, Bond University, Australia
  • Filip Vladimir Kukic Abu Dhabi Police
  • Eduardo Marins Superior School of Physical Education, Federal University of Pelotas, Pelotas, Rio Grande do Sul, Brazil
  • Cheryl Lim Soldier Systems Integration Laboratory, Centre of Excellence for Soldier Performance, Singapore
  • Jay Dawes Tactical Fitness and Nutrition Lab, School of Kinesiology, Applied Health, and Recreation, Oklahoma State University, Stillwater, OK, USA
  • Robert Lockie Center for Sport Performance, Department of Kinesiology, California State University, Fullerton, Fullerton, California, USA
Keywords: law enforcement, fitness, training, specialists



Tactical personnel such as Special Weapons and Tactics (SWAT) police are required to carry occupational loads of approximately 20 kg and, on occasion, more than 40 kg. These occupational loads have been found to negatively impact officer mobility. The aim of this study was to investigate the impact of load carriage on lower-body power in SWAT Police.


Six active male officers of a state police SWAT unit (mean age = 34.0 ± 7.4 years, mean height = 184.2 ± 3.3 cm, mean body mass = 96.3 ± 6.4 kg, mean years of SWAT experience = 6.0 ± 6.8 years) volunteered to participate. Ethics approval for the study was obtained by Bond University Human Research Ethics Committee (RO1585). Lower-body power was measured using a repeated vertical jump (VJ) test of three jumps with data collected using an uni-axial portable force plate sampled at 600 Hz and filtered using a 4th order Butterworth filter with a cut-off frequency of 50 Hz. Force-time data were subsequently analysed. The VJ variables, peak velocity, peak force, peak power, and jump height and landing force were measured. Officers randomly completed the VJ in both an unloaded condition (5.5 kg – fatigues and M4 weapon slung) and a tactically loaded condition (23.5 ± 2.8 kg: 24.5 ± 3.4% body mass) with all operational equipment. The VJ heights of all three jumps were averaged to provide a final VJ height for analysis.


Paired sample t-tests were used to evaluate differences between the tests in loaded and unloaded conditions. Magnitude of differences was calculated according to Cohen’s effect size. Pearson’s correlations were conducted to investigate relationships between the unloaded and loaded condition for each variable. The significance level for all data was set at p < .05.


The results of the paired samples t-test revealed no statistical difference between the initial and third VJ height performed in the repeated VJ test, for either the unloaded (p = .864) or loaded (p = .898) conditions. There were significant differences (p < .001) between the unloaded and loaded conditions in VJ height (0.34 ± 0.02 m; 0.26 ± 0.02 m, respectively) and peak velocity (2.57 ± 0.07 m.s-1; 2.26 ± 0.08 m.s-1, respectively) with large effect sizes (d=-1.73 and -1.71 respectively). All measures, with the exception of landing force (r=.46, p=.35) were significantly and strongly correlated


Lower body power in SWAT Officers is reduced during load carriage. This can potentially lead to decreased tactical performance in critical tasks, such as seeking, or moving between, cover. Officers should train in both unloaded and loaded conditions to increase lower body power and mitigate landing impacts.

Keywords: law enforcement, fitness, training, specialists


Baran, K., Dulla, J., Orr, R., Dawes, J., & Pope, R. (2018). Duty loads carried by the LA sheriff's department deputies. Journal of Australian Strength and Conditioning, 26(5), 34-38.
Carbone, P. D., Carlton, S. D., Stierli, M., & Orr, R. M. (2014). The impact of load carriage on the marksmanship of the tactical police officer: A pilot study. Journal of Australian Strength and Conditioning, 22(2), 50-57.
Carlton, S. D., & Orr, R. M. (2014). The impact of occupational load carriage on carrier mobility: a critical review of the literature. Int J Occup Saf Ergon, 20(1), 33-41.
Cocke, C., & Orr, R. (2015). The impact of physical training programs on the fitness of tactical populations: a critical review. Journal of Australian Strength and Conditioning,23(1)39-52.
Cormack, S. J., Newton, R. U., McGuigan, M. R., & Doyle, T. L. (2008). Reliability of measures obtained during single and repeated countermovement jumps. Int J Sports Physiol Perform, 3(2), 131.
Dawes, J., Orr, R., Flores, R. R., Lockie, R. G., Kornhauser, C., & Holmes, R. (2017). A physical fitness profile of state highway patrol officers by gender and age. Ann Occup Environ Med, 29(1), 16. doi:
Dawes, J., Orr, R. M., Elder, C. L., Krall, K., Stierli, M., & Schilling, B. (2015). Relationship between selected measures of power and strength and linear running speed amongst Special Weapons And Tactics Police Officers. Journal of Australian Strength and Conditioning, 23(3), 22-26.
De Maio, M., Onate, J., Swain, D., Morrison, S., Ringleb, S., & Naiak, D. (2009). Physical Performance Decrements in Military Personnel Wearing Personal Protective Equipment (PPE). Naval Medical Center Portsmouth, VA:USA.
Dempsey, P., Handcock, P. J., & Rehrer, N. J. (2013). Impact of police body armour and equipment on mobility. Appl Ergon, 44(6), 957-961.
Dempsey, P. C., Handcock, P. J., & Rehrer, N. J. (2014). Body armour: the effect of load, exercise and distraction on landing forces. J Sports Sci, 32(4), 301-306. doi:10.1080/02640414.2013.823226
Irving, S., Orr, R., & Pope, R. (2019). Profiling the Occupational Tasks and Physical Conditioning of Specialist Police. Int J Exerc Sci, 12(3) 173-186.
Lewinski, W. J., Dysterheft, J. L., Dicks, N. D., & Pettitt, R. W. (2015). The influence of officer equipment and protection on short sprinting performance. Appl Ergon, 47, 65-71. doi:10.1016/j.apergo.2014.08.017
Mala, J., Szivak, T. K., & Kraemer, W. J. (2015). Improving Performance of Heavy Load Carriage During High-Intensity Combat-Related Tasks. Strength Cond J, 37(4), 43-52.
Martin, P. E., & Nelson, R. C. (1985). The effect of carried loads on the combative movement performance of men and women. Medicine, 150(7), 357-362.
Mukaka, M. M. (2012). A guide to appropriate use of Correlation coefficient in medical research. Malawi Med J, 24(3), 69-71.
Orr, R. (2010). The history of the soldier's load. Australian Army Journal, 7(2), 67-88.
Orr, R., Dawes, J., Lockie, R. G., & Godeassi, D. (2019). The Relationship Between Lower-Body Strength and Power, and Load Carriage Tasks: A Critical Review. Int J Exerc Sci, 12(6), 1001.
Orr, R., Kukić, F., Cvorovic, A., Koropanovski, N., Janković, R., Dawes, J., & Lockie, R. (2019). Associations between Fitness Measures and Change of Direction Speeds with and without Occupational Loads in Female Police Officers. Int J Environ Res Public Health, 16(1947). doi:10.3390/ijerph16111947
Orr, R., Pope, R., Johnston, V., & Coyle, J. (2014). Soldier occupational load carriage: a narrative review of associated injuries. Int J Inj Contr Saf Promot, 21(4), 388-396. doi:10.1080/17457300.2013.833944
Pazin, N., Berjan, B., Nedeljkovic, A., Markovic, G., & Jaric, S. (2013). Power output in vertical jumps: does optimum loading depend on activity profiles? Eur J Appl Physiol, 113(3), 577-589.
Pryor, R. R., Colburn, D., Crill, M. T., Hostler, D. P., & Suyama, J. (2012). Fitness characteristics of a suburban special weapons and tactics team. Journal of Strength and Conditioning Research, 26(3), 752-757.
Shephard, R., & Bonneau, J. (2002). Assuring gender equity in recruitment standards for police officers. Can J Appl Physiol, 27, 263-295. doi:10.1139/h02-016
Son, S.-Y., Lee, J.-Y., & Tochihara, Y. (2013). Occupational stress and strain in relation to personal protective equipment of Japanese firefighters assessed by a questionnaire. Ind Health, 51(2), 214-222.
Stubbs, D., David, G., Woods, V., & Beards, S. (2008). Problems associated with police equipment carriage with Body Armour, including driving. In Contemporary Ergonomics 2008: Proceedings of the International Conference on Contemporary Ergonomics (CE2008), 1-3 April 2008, Nottingham, UK, 23-28.
Sullivan, G. M., & Feinn, R. (2012). Using effect size—or why the P value is not enough. J Grad Med Educ, 4(3), 279-282.
Suzovic, D., Markovic, G., Pasic, M., & Jaric, S. (2013). Optimum load in various vertical jumps support the maximum dynamic output hypothesis. Int J Sports Med, 34(11), 1007-1014.
Taylor, N. A., Burdon, C. A., van den Heuvel, A. M., Fogarty, A. L., Notley, S. R., Hunt, A. P., . . . Peoples, G. E. (2016). Balancing ballistic protection against physiological strain: evidence from laboratory and field trials. Appl Physiol Nutr Metab, 41(2), 117-124. doi:10.1139/apnm-2015-0386
Walsh, M. S., Ford, K. R., Bangen, K. J., Myer, G. D., & Hewett, T. E. (2006). The validation of a portable force plate for measuring force-time data during jumping and landing tasks. J Strength Cond Res, 20(4), 730.
Effects of Physical Activity on Anthropological Status in Security Agency Per