PURPOSE: To characterize the impact of prolonged work, underfeeding, and sleep deprivation (i.e., sustained operations; SUSOPS) on physical and occupational related performance during military operational stress. METHODS: Ten male soldiers were tested on days 1 (D1), 3 (D3), and 4 (D4) of a control and an experimental week that included prolonged physical work (total daily energy expenditure approximately 4,500 kcal x d(-1)), underfeeding (approximately 1,600 kcal x d(-1)), and sleep deprivation (approximately 2 h x d(-1)). Body composition was measured with dual-energy x-ray absorptiometry (DEXA). Ballistic power was assessed by 30 repetitive squat jumps and bench-press throws. Military-relevant occupational performance was evaluated with a 10-min box lift, obstacle course, grenade throw, rifle marksmanship, and a 25-min wall-build task. RESULTS: Fat-free mass (-2.3%) and fat mass (-7.3%) declined (P </= 0.05) during SUSOPS. Squat-jump mean power (-9%) and total work (-15%) declined (P </= 0.05) during SUSOPS. Bench-press power output, grenade throw, and marksmanship for pop-up targets were not affected. Obstacle course and box-lift performances were lower (P </= 0.05) on D3 but showed some recovery on D4. Wall building was approximately 25% lower (P </= 0.05) during SUSOPS. CONCLUSION: Decrements in performance during SUSOPS are primarily restricted to tasks that recruit muscles that are over-utilized without adequate recovery. General military skill tasks and occupational physical performance tasks are fairly well maintained.
PURPOSE: To characterize the impact of prolonged work, underfeeding, and sleep deprivation (i.e., sustained operations; SUSOPS) on physical and occupational related performance during military operational stress. METHODS: Ten male soldiers were tested on days 1 (D1), 3 (D3), and 4 (D4) of a control and an experimental week that included prolonged physical work (total daily energy expenditure approximately 4,500 kcal x d(-1)), underfeeding (approximately 1,600 kcal x d(-1)), and sleep deprivation (approximately 2 h x d(-1)). Body composition was measured with dual-energy x-ray absorptiometry (DEXA). Ballistic power was assessed by 30 repetitive squat jumps and bench-press throws. Military-relevant occupational performance was evaluated with a 10-min box lift, obstacle course, grenade throw, rifle marksmanship, and a 25-min wall-build task. RESULTS: Fat-free mass (-2.3%) and fat mass (-7.3%) declined (P </= 0.05) during SUSOPS. Squat-jump mean power (-9%) and total work (-15%) declined (P </= 0.05) during SUSOPS. Bench-press power output, grenade throw, and marksmanship for pop-up targets were not affected. Obstacle course and box-lift performances were lower (P </= 0.05) on D3 but showed some recovery on D4. Wall building was approximately 25% lower (P </= 0.05) during SUSOPS. CONCLUSION: Decrements in performance during SUSOPS are primarily restricted to tasks that recruit muscles that are over-utilized without adequate recovery. General military skill tasks and occupational physical performance tasks are fairly well maintained.
Authors: Samuel N Cheuvront; Robert W Kenefick; Brett R Ely; Everett A Harman; John W Castellani; Peter N Frykman; Bradley C Nindl; Michael N Sawka Journal: Eur J Appl Physiol Date: 2010-04-09 Impact factor: 3.078
Authors: Stephen D Myers; Trevor D Dobbins; Stuart King; Benjamin Hall; Ruth M Ayling; Sharon R Holmes; Tom Gunston; Rosemary Dyson Journal: Eur J Appl Physiol Date: 2010-12-14 Impact factor: 3.078
Authors: Nancy E Murphy; Christopher T Carrigan; J Philip Karl; Stefan M Pasiakos; Lee M Margolis Journal: Sports Med Date: 2018-09 Impact factor: 11.136
Authors: F Proessl; M C Canino; M E Beckner; W R Conkright; A D LaGoy; A M Sinnott; S R Eagle; B J Martin; A J Sterczala; P G Roma; M N Dretsch; Qi Mi; F Ferrarelli; A Germain; C Connaboy; B C Nindl; S D Flanagan Journal: J Appl Physiol (1985) Date: 2021-12-02
Authors: Heikki Kyröläinen; Jari Karinkanta; Matti Santtila; Harri Koski; Matti Mäntysaari; Teemu Pullinen Journal: Eur J Appl Physiol Date: 2007-11-27 Impact factor: 3.078
Authors: Jordane G Grenier; Guillaume Y Millet; Nicolas Peyrot; Pierre Samozino; Roger Oullion; Laurent Messonnier; Jean-Benoît Morin Journal: PLoS One Date: 2012-08-22 Impact factor: 3.240