Evidence of negative energy balance using doubly labelled water in elite Kenyan endurance runners prior to competition
Evidence of negative energy balance using doubly labelled water in elite Kenyan endurance runners prior to competition
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DOI：
10.1079/bjn20051608
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发表时间：
2006-01-01
影响因子：
3.6
通讯作者：
Pitsiladis, YP
中科院分区：
文献类型：
--
作者：
Fudge, BW;Westerterp, KR;Pitsiladis, YP
先前的研究发现，肯尼亚耐力跑运动员在训练期间和比赛前处于负能量平衡状态。本研究的目的是评估能量平衡在9个精英肯尼亚耐力跑在繁重的训练。能量的摄入和支出，确定超过7天，分别使用称重膳食摄入量和双标记水。运动员平均处于负能量平衡（平均能量摄入13 241（SD 1330）kJ/d与平均能量消耗14 611（SD 1043）kJ/d; P=0.046），尽管体重没有减少（平均56.0（SD 3.4）kg与55.7（SD 3.6）kg; P=0.285）。计算的漏报率为13%（范围为-24至+9%），几乎完全由漏报（9%（范围为-55至+39%））解释，而不是缺乏显著的漏报（即总饮水量与失水量没有差异（平均4.2（SD 0.6）l/d v. 4.5（SD 0.8）l/d; P=0.496））。液体摄入量适中，主要包括水（0.9（SD 0.5）l/d）和奶茶（0.9（SD 0.3）l/d）。饮食中碳水化合物含量高（67.3（SD 7.8）%），蛋白质（15.3（SD 4.0）%）和脂肪（17.4（SD 3.9）%）充足。这些结果证实了之前的观察，即肯尼亚跑步者在高强度训练期间处于负能量平衡状态。负能量平衡会导致体重减少，当与高碳水化合物饮食相结合时，将有可能在短期内通过减少跑步的能量消耗来提高耐力跑步的表现。
Previous studies have found Kenyan endurance runners to be in negative energy balance during training and prior to competition. The aim of the present study was to assess energy balance in nine elite Kenyan endurance runners during heavy training. Energy intake and expenditure were determined over 7 d using weighed dietary intake and doubly labelled water, respectively. Athletes were on average in negative energy balance (mean energy intake 13 241 (SD 1330) kJ/d v. mean energy expenditure 14 611 (SD 1043) kJ/d; P=0.046), although there was no loss in body mass (mean 56.0 (SD 3.4) kg v. 55.7 (SD 3.6) kg; P=0.285). The calculation of underreporting was 13 % (range -24 to +9 %) and almost entirely accounted for by undereating (9 % (range -55 to +39 %)) as opposed to a lack of significant underrecording (i.e. total water intake was no different from water loss (mean 4.2 (SD 0.6) l/d v. 4.5 (SD 0.8) l/d; P=0.496)). Fluid intake was modest and consisted mainly of water (0.9 (SD 0.5) l/d) and milky tea (0.9 (SD 0.3) l/d). The diet was high in carbohydrate (67.3 (SD 7.8) %) and sufficient in protein (15.3 (SD 4.0) %) and fat (17.4 (SD 3.9) %). These results confirm previous observations that Kenyan runners are in negative energy balance during periods of intense training. A negative energy balance would result in a reduction in body mass, which, when combined with a high carbohydrate diet, would have the potential in the short term to enhance endurance running performance by reducing the energy cost of running.