S66 Abstracts / Journal of Science and Medicine in Sport 20S (2017) S61–S71 109 A job task analysis of digging duties conducted by the ground close combat roles in the UK Armed Forces Ben J. Lee 1,∗ , Stephen D. Myers 1 , Ella F. Walker 1 , Sarah L. Coakley 1 , Carla A. Rue 1 , Tessa R. Flood 1 , Julianne Doherty 1 , Christopher A.J. Vine 1 , Mark P. Rayson 2 , Joseph J. Knapik 3 , Deborah L. Gebhardt 4 , Bradley Nindl 5 , Pieter E.H. Brown 6 , Sarah Jackson 7 , Julie P. Greeves 7 , Sam D. Blacker 1 1 University of Chichester, United Kingdom 2 Mark Rayson Consulting Limited, United Kingdom 3 Independant Consultant, USA 4 Human Resources Research Organization, USA 5 University of Pittsburgh, USA 6 Institute of Naval Medicine, UK 7 Army Personnel Research Capability, UK Purpose: A job task analysis (JTA) involves collecting subjective and objective data to quantify the physical demands of criterion tasks performed in a job role and is fundamental in developing physical employment standards (PES). The aim of this study was to conduct a JTA to quantify the requirements and physical demands of digging activity for personnel serving in Ground Close Combat (GCC) roles in the UK Armed Forces. Methods: Subjective data to describe the process of manually preparing a defensive position were gathered through 10 focus groups (one with each of 10 defined GCC roles) which were rat- ified through rank stratified surveys (n = >1495 personnel). On a separate occasion eight male GCC personnel (mean ± SD: age 22 ± 3 years; stature 179 ± 5 cm; body mass 87.85 ± 11.64 kg) were instru- mented with heart rate monitors and observed over a period of ∼52 h whilst preparing a defensive position. Video footage of the defensive position construction and doctrine were used to define a typical slow (12 shovels min -1 ) and fast (22 shovels min -1 ) digging rate. The metabolic cost (VO 2 ) of the digging at the slow and fast rates was measured using the Douglas bag method in 18 personnel at the slow rate and 19 personnel at the fast rate. Data are expressed as mean ± SD or (range) and differences between groups assessed using independent sample t-tests. Results: The focus groups and surveys identified that digging trenches, filling sand-bags, and shovelling debris were the key dig- ging tasks involved in preparing defensive positions. Mean (range) heart rate during de-turfing, trench excavation, sandbag filling, and re-turfing were 59 (54–65), 50 (40–71), 46 (39–53) and 58 (52–86) percent of age predicted maximum heart rate, respectively. Dur- ing digging, VO 2 was 1.46 ± 0.22 L min -1 at 12 shovels min -1 which increased to 1.86 ± 0.33 L min -1 at 22 shovels min -1 (p < 0.001), with no difference in respiratory exchange ratio observed between 12 and 22 shovels min -1 (0.92 ± 0.04 vs. 0.94 ± 0.08, p = 0.303). Conclusion: Manually preparing a defensive position requires personnel to dig at varying rates which requires a significant contri- bution from aerobic energy provision. The measured VO 2 of these tasks can be used to model the aerobic capacity required to sus- tain digging tasks for given duration to inform future GCC PES and investigate whether adopting a faster digging rate may be more efficient than a slower rate. Support: This study was funded by the UK Ministry of Defence, Army Research Personnel Capability (APRC) through the Defence Human Capability Science and Technology Centre (DHCSTC). https://doi.org/10.1016/j.jsams.2017.09.124 110 The application of a mathematical model to estimate the aerobic capacity required to complete an 8-mile loaded march from an individual’s body mass Sarah L. Coakley 1,∗ , Stephen D. Myers 1 , Ella F. Walker 1 , Beverley Hale 1 , Joseph J. Knapik 2 , Sarah Jackson 3 , Julie P. Greeves 3 , Sam D. Blacker 1 1 Occupational Performance Research Group, Department of Sport and Exercise Sciences, University of Chichester, UK 2 Independent Consultant, Fitness, Injury, and Performance Analysis, USA 3 Army Personnel Research Capability, Army HQ, UK Introduction: The British Army Annual Fitness Test (AFT) for Infantry personnel is an 8-mile Loaded March (LM) that must be completed in 2 h, carrying 25 kg. The study aims were (1) to develop a mathematical model to estimate the minimum ˙ VO 2 max and 2.4 km run time (RUN) to successfully complete the AFT and (2) quantify the proportion of a sample of British Army recruits who could meet the pass standard. Methods: Steps were as follows: [S1] The metabolic cost (watts) of the AFT was calculated 1 and converted to a rate of energy expenditure (kcal min -1 ) by multiplying watts by 0.014. [S2] Abso- lute ˙ VO 2 (L min -1 ) was calculated by dividing the rate of energy expended by 5.0. [S3] Relative ˙ VO 2 was calculated for a 50th per- centile British Army male (81 kg) and female (67 kg) by dividing the absolute VO 2 by the given body mass and multiplying the outcome by 1000. [S4] Maximum % ˙ VO 2 max that can be sustained for the AFT was estimated using a Sustainment Time Model (STM). 2 [S5] Esti- mated relative ˙ VO 2 from S3 was divided by the % ˙ VO 2 max derived from the STM to get the minimum ˙ VO 2 max required to success- fully complete the AFT. [S6] Corresponding RUN for the estimated ˙ VO 2 max was calculated using reference tables 3 relating ˙ VO 2 max to a multistage shuttle run test and converting to RUN. From a database of 60,139 British Army Recruits [55,406 males; 4733 females] min- imum RUN were predicted for each individual using S1–S6, and compared to actual RUN to quantify the proportion of recruits who could meet the pass standard. Results: The minimum ˙ VO 2 max required to complete the AFT for a 50th percentile male and female was 42.3 and 44.7 ml kg -1 min -1 respectively, corresponding to ∼58% ˙ VO2max, and equating to minimum RUN of 11:36 and 10:52 min:s for males and females respectively. It was estimated 84% of males and 4% of females would pass the AFT at their current level of fitness. Conclusions: The method presented provides a simple model to predict the aerobic capacity required to complete a LM using an individual’s body mass. Further research is required to validate the model by comparing predicted versus actual ˙ VO 2 max and RUN required to pass the LM. The successful completion of the AFT is likely to be higher in incumbents compared to recruits’. Support: This study was funded by the UK Ministry of Defence, Army Research Personnel Capability (APRC) through the Defence Human Capability Science and Technology Centre (DHCSTC). References 1. Pandolf et al. J Appl Physiol 1977; 43:577. 2. Drain et al. Appl Ergon 2016; 52:85. 3. Ramsbottom et al. Br J Sports Med 1988; 22:141. https://doi.org/10.1016/j.jsams.2017.09.125