夏季越野锻炼对负重行军铁代谢的影响

Effect of the Cross-country Race Training on Iron Metabolism during War-load Marching in Summer

20名健康战士在热气候下(三球温度指数—WBGT 31.73℃)越野锻炼连续10次(天),锻炼期前、后进行一次标准热应激试验,即在热气候下(WBGT 30.3℃)负重行军90min(7km),以比较评价热锻炼对机体铁代谢的影响。结果显示:经越野锻炼10次(天)后,标准试验后血清铁含量由锻炼前显著降低变为增高34.0%,汗铁浓度显著降低,负重行军190rain内汗铁丢失由0.905mg降至0.553mg,全天汗铁丢失由4.772mg降至2.250mg(p<0.05),粪、尿铁排出量增加不多,全日铁总排泄量由5.962mg降至3.892mg,体温调节功能增强,体力得到明显改善。锻炼期间每日人均摄取铁34.4—36.8mg,而锻炼后的清晨血清铁含量降低非常显著,血红蛋白(Hb)和红细胞(RBC)较锻炼前稍降,因此应适当增加动物性食物铁为宜。

Twenty physically fit soldiers were asked to perform the cross-country race training once a day for ten days under hot climate (WBGT=31.73℃). Before and after the training period, a standard heat stress test of 90 min marching (7 km) with war-load in the natural hot climate (WBGT=30.3 ℃) was done by every subject to evaluate the effect of heat training on iron metabolism. The results showed that the standard heat stress test after training caused a 34 increase of serum iron content,while it caused a distinct decrease of serum iron content before training. Sweat iron concentration reduced significantly after training, loss of iron from sweat during 90 min marching decreased from 0.905 mg before training to 0.553 mg after training ,and whole day loss of iron through sweat decreased from 4.772 mg before training to 2.250 mg after training (p<0.05). Iron excreted from stool and urine increased not obviously. Total amount of iron excreted decreased from 5.962 mg/day before training to 3.892 mg/day after training. Body temperature regulation and physical strength improved markedly. The average iron intake was 34.4-36.8 mg/day during the training period. However,the contents of serum iron in the early morning reduced significantly after training for ten days, and HB and RBC decreased slightly when compared with those before training, so it should be appropriate to supply suitable amount of iron by animal food.