Dimitriou Lygeri, Lockey J, Castell L
London Sport Institute, Middlesex University, London, UK.
Green Templeton College, University of Oxford, Oxford, Oxon, UK.
J R Army Med Corps. 2017 Feb;163(1):39-47. doi: 10.1136/jramc-2015-000608. Epub 2016 Feb 29.
Respiratory illnesses are a leading cause of morbidity and medical discharge in the military. This study aimed to investigate the effects of baseline aerobic fitness on haematological, salivary and mood variables, and simultaneously, in a novel approach, to identify factors precipitating illness and attrition rate in recruits during military training.
Thirty-five healthy male recruits from an Army Training Regiment undertaking 12 weeks of training were prospectively investigated. Their 2.4 km run time (RT) was used as a surrogate of baseline aerobic fitness. Saliva and venous blood samples were analysed for secretory IgA, full blood counts and cell cytokine production (interleukin (IL) 6 and IL-8), respectively. Each recruit completed questionnaires on mood profile, and gastrointestinal and upper respiratory tract symptoms (URTS).
Significant salivary and haematological perturbations were observed and coincided with increased duration of URTS/week and mood disturbance over this military training period. From Start to End: leucocyte count decreased by 28% (p<0.001); neutrophil percentage (%) decreased by 13% (p<0.01); lymphocyte % increased by 17% (p<0.05); the neutrophil:lymphocyte ratio decreased by 22% (p<0.01); eosinophil% increased by 71% (p<0.01). From Start to Mid to End: monocyte% increased by 68% at Mid (p<0.01) but only by 30% at End (p<0.01); IL-6 increased by 39% at Mid (p<0.01) and a further 61% by End. The 2.4 km RT was significantly associated with URTS duration (p<0.01). In addition, a 1-min increase in 2.4 km RT increased a recruit's risk 9.8-fold of developing URTS lasting, on average, 3.36 days/week. In recruits ranked with high-URTS duration their RT was 48 s slower (p<0.01) than those with low-URTS, and their attrition rate reached 45%.
The least fit recruits may have found training more physically demanding as reflected in the higher URTS duration, which may have led to a high attrition rate from the Army. It is worth considering that baseline aerobic fitness might be an important factor in illness development and attrition rate in recruits during this type of military training.
呼吸系统疾病是军队中发病和因病退伍的主要原因。本研究旨在调查基线有氧适能对血液学、唾液和情绪变量的影响，同时，采用一种新方法，确定新兵在军事训练期间引发疾病的因素和流失率。
对来自一个陆军训练团的35名健康男性新兵进行了为期12周的前瞻性调查。他们的2.4公里跑步时间（RT）被用作基线有氧适能的替代指标。分别对唾液和静脉血样本进行分泌型免疫球蛋白A、全血细胞计数和细胞细胞因子产生（白细胞介素（IL）-6和IL-8）分析。每名新兵完成了关于情绪状况、胃肠道和上呼吸道症状（URTS）的问卷调查。
在这段军事训练期间，观察到显著的唾液和血液学扰动，同时URTS/周持续时间增加和情绪紊乱。从开始到结束：白细胞计数下降28%（p<0.001）；中性粒细胞百分比（%）下降13%（p<0.01）；淋巴细胞%增加17%（p<0.05）；中性粒细胞：淋巴细胞比值下降22%（p<0.01）；嗜酸性粒细胞%增加71%（p<0.01）。从开始到中期再到结束：单核细胞%在中期增加68%（p<0.01），但在结束时仅增加30%（p<0.01）；IL-6在中期增加39%（p<0.01），到结束时再增加61%。2.4公里RT与URTS持续时间显著相关（p<0.01）。此外，2.4公里RT每增加1分钟，新兵患URTS的风险增加9.8倍，平均持续3.36天/周。在URTS持续时间较长的新兵中，他们的RT比URTS持续时间较短的新兵慢48秒（p<0.01），他们的流失率达到45%。
身体最不健康的新兵可能觉得训练对身体要求更高，这反映在较高的URTS持续时间上，这可能导致军队的高流失率。值得考虑的是，基线有氧适能可能是这类军事训练中新兵疾病发展和流失率的一个重要因素。
