Costa R J S, Jones G E, Lamb K L, Coleman R, Williams J H H
Chester Centre for Stress Research, and Department of Sport and Exercise Science, University College Chester, Parkgate Road, Chester CH1 4BJ, England, UK.
Int J Sports Med. 2005 Dec;26(10):880-5. doi: 10.1055/s-2005-837467.
The present study observed the effects of a 6-day high carbohydrate (H-CHO) diet on salivary cortisol and IgA during a period of increased exercise workload. Thirty-two competitively trained male triathletes were randomly allocated into a self-selected (SS), or an H-CHO (12 g CHO kgbm (-1) . day (-1)) dietary group. In addition to their training regimes, all subjects performed a 1-hour running exercise bout at 70 % V.O (2max) . d (-1), for six days. Saliva samples were taken pre, immediately post, and morning post-exercise bout on days 1, 4, and 6. The concentrations of s-IgA and cortisol were determined by ELISA assays. There was a significant (p < 0.001) interaction between Group x Time for cortisol, with a marked increase in concentrations occurring in the SS dietary group pre to post exercise, and pre to morning post-exercise (p < 0.01). Conversely, a significant (p = 0.009) Group x Time interaction reflected higher post exercise s-IgA concentrations (p < 0.005) than pre exercise in the H-CHO diet group. Blood glucose concentration decreased pre to post exercise in the SS diet group (p < 0.01), whilst remaining stable in the H-CHO group. It is concluded that the consumption of a high CHO diet throughout a 6-day period of overtraining had a favourable effect on markers of immune activity and thereby reduced the susceptibility of these endurance athletes to upper respiratory tract infection URTI.
本研究观察了在运动负荷增加期间，为期6天的高碳水化合物（H-CHO）饮食对唾液皮质醇和免疫球蛋白A（IgA）的影响。32名经过竞技训练的男性铁人三项运动员被随机分为自选饮食（SS）组或H-CHO（12 g CHO·kgbm⁻¹·d⁻¹）饮食组。除训练计划外，所有受试者每天以70%最大摄氧量（V.O₂max）进行1小时跑步运动，持续6天。在第1、4和6天运动前、运动后即刻以及运动后次日早晨采集唾液样本。采用酶联免疫吸附测定法（ELISA）测定分泌型IgA（s-IgA）和皮质醇的浓度。皮质醇的组×时间交互作用显著（p < 0.001），SS饮食组运动前至运动后以及运动前至运动后次日早晨皮质醇浓度显著升高（p < 0.01）。相反，显著的（p = 0.009）组×时间交互作用表明，H-CHO饮食组运动后s-IgA浓度高于运动前（p < 0.005）。SS饮食组运动前至运动后血糖浓度降低（p < 0.01），而H-CHO组血糖浓度保持稳定。得出结论，在为期6天的过度训练期间摄入高碳水化合物饮食对免疫活性标志物有有利影响，从而降低了这些耐力运动员上呼吸道感染（URTI）的易感性。
