Bourque S P, Pate R R, Branch J D
Department of Health, Physical Education, and Recreation, University of North Carolina at Wilmington 28403-3297, USA.
J Am Diet Assoc. 1997 Oct;97(10):1116-21. doi: 10.1016/S0002-8223(97)00272-1.
This study examined the effects of 12 weeks of endurance exercise training on iron status measures in previously inactive women and compared the effects of weight-bearing endurance exercise training and non-weight-bearing endurance exercise on iron status measures.
Randomized, experimental study.
Thirty-one healthy, inactive women (aged 23 to 43 years) with apparently normal iron stores (serum ferritin concentration > or = 20 micrograms/L) were recruited from the local area by newspaper advertisements and campus mailings. Twenty-one subjects completed the study (mean +/- standard deviation for age = 32 +/- 5 years, for body mass index = 23.1 +/- 4.9, and for maximum oxygen consumption [VO2max] = 33.8 +/- 6.3 mL/kg per minute).
Subjects were randomly assigned to one of three groups: an inactive control group, a walking/running group, or a cycling group. Subjects in the two exercise groups trained three to four times per week at 80% VO2max for 12 weeks. Exercise training sessions were monitored and energy expenditure increased from 150 kcal per session (week 1) to 375 kcal per session (weeks 9 to 12). Subjects in the inactive control group were instructed to maintain their normal activity patterns for the duration of the study. All subjects were instructed to maintain their normal dietary habits.
Serum ferritin concentration, serum iron concentration, percentage saturation of transferrin, total iron-binding capacity, serum haptoglobin concentration, and other selected hematologic variables were measured at baseline and at weeks 2, 4, 8, and 12.
Repeated measures analysis of variance was used to examine group x time interactions in changes in iron status measures. Statistical significance was reached at P < .05.
Analysis of variance indicated that serum ferritin concentration did not change significantly (P = .59) during the 12 weeks in the walking/running group (mean +/- standard deviation from 41.28 +/- 14.22 to 27.41 +/- 9.74 micrograms/L) or the cycling group (from 65.81 +/- 37.62 to 41.06 +/- 26.38 micrograms/L) compared with the control group (from 47.55 +/- 15.87 to 31.56 +/- 10.57 micrograms/L). Values for serum iron, total iron-binding capacity, percentage saturation of transferrin, and haptoglobin also did not change significantly (P > .30) in the walking/running or cycling groups compared with the control group.
APPLICATIONS/CONCLUSIONS: Results of this study suggest that participation in 12 weeks of moderate-intensity endurance exercise training (walking/running or cycling) is not associated with negative effects on selected measures of iron status in healthy, previously untrained women with normal iron stores (serum ferritin > or = 20 micrograms/L).
本研究探讨了为期12周的耐力运动训练对既往缺乏运动的女性铁状态指标的影响，并比较了负重耐力运动训练和非负重耐力运动对铁状态指标的影响。
随机实验研究。
通过报纸广告和校园邮件从当地招募了31名健康、缺乏运动的女性（年龄23至43岁），她们的铁储备明显正常（血清铁蛋白浓度≥20微克/升）。21名受试者完成了研究（年龄的均值±标准差=32±5岁，体重指数=23.1±4.9，最大耗氧量[VO2max]=33.8±6.3毫升/千克每分钟）。
受试者被随机分为三组之一：非运动对照组、步行/跑步组或骑自行车组。两个运动组的受试者每周训练三到四次，以80%的VO2max强度训练12周。运动训练课程受到监测，能量消耗从每次训练150千卡（第1周）增加到每次训练375千卡（第9至12周）。非运动对照组的受试者被要求在研究期间保持正常的活动模式。所有受试者都被要求保持正常的饮食习惯。
在基线以及第2、4、8和12周时测量血清铁蛋白浓度、血清铁浓度、转铁蛋白饱和度百分比、总铁结合力、血清触珠蛋白浓度以及其他选定的血液学变量。
采用重复测量方差分析来检验铁状态指标变化中的组×时间交互作用。P<0.05时具有统计学意义。
方差分析表明，与对照组（从47.55±15.87微克/升降至31.56±10.57微克/升）相比，步行/跑步组（从41.28±14.22微克/升降至27.41±9.74微克/升）或骑自行车组（从65.81±37.62微克/升降至41.06±26.38微克/升）在12周内血清铁蛋白浓度没有显著变化（P=0.59）。与对照组相比，步行/跑步组或骑自行车组的血清铁、总铁结合力、转铁蛋白饱和度百分比和触珠蛋白的值也没有显著变化（P>0.30）。
应用/结论：本研究结果表明，对于铁储备正常（血清铁蛋白≥20微克/升）、健康且既往未受过训练的女性，参与为期12周的中等强度耐力运动训练（步行/跑步或骑自行车）与所选铁状态指标的负面影响无关。
