Fat and carbohydrate metabolism during exercise in elderly and young subjects
Fat and carbohydrate metabolism during exercise in elderly and young subjects
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DOI：
10.1152/ajpendo.1996.271.6.e983
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发表时间：
1996-12-01
影响因子：
5.1
通讯作者：
Klein, S
中科院分区：
文献类型：
--
作者：
Sial, S;Coggan, AR;Klein, S
我们评估了在中等强度运动中，衰老对脂肪和碳水化合物代谢的影响。对6名按性别和瘦体重匹配的老年人(73+/-2岁)和6名年轻人(2 6+/-2岁)进行60min功率自行车运动，测定血浆甘油、游离脂肪酸(FFA)、葡萄糖出现率(R(A))和底物氧化。老年组在最大摄氧量的56+/-3%的运动中被研究，而年轻人在运动中以与老年受试者相同的绝对和相似的相对强度进行研究。在相同的绝对或相似的相对强度下，老年受试者在运动中的平均脂肪氧化比年轻人低25%-35%(P<；0.05)。老年组的平均碳水化合物氧化量比年轻人在相同的绝对强度下运动高35%(P<；0.001)，但比年轻人在相同的相对强度下运动低40%(P<；0.001)。老年人的平均FFA R(A)比年轻人在相同的绝对强度下运动高35%(P<；0.05)，但比年轻人在相似的相对强度下运动的低35%(P<；0.05)。我们的结论是，在中等强度运动中，老年男性和女性的脂肪氧化减少，而碳水化合物氧化增加。底物氧化的变化是由骨骼肌呼吸能力的年龄相关变化引起的，因为脂解率和FFA利用率在老年受试者中不是速率限制。
We evaluated the effect of aging on fat and carbohydrate metabolism during moderate intensity exercise. Glycerol, free fatty acid (FFA), and glucose rate of appearance (R(a)) in plasma and substrate oxidation were determined during 60 min of cycle ergometer exercise in six elderly (73 +/- 2 yr) and six young adults (26 +/- 2 yr) matched by gender and lean body mass. The elderly group was studied during exercise performed at 56 +/- 3% of maximum oxygen uptake, whereas the young adults were studied during exercise performed at the same absolute and at a similar relative intensity as the elderly subjects. Mean fat oxidation during exercise was 25-35% lower in the elderly subjects than in the young adults exercising at either the same absolute or similar relative intensities (P < 0.05). Mean carbohydrate oxidation in the elderly group was 35% higher than the young adults exercising at the same absolute intensity (P < 0.001) but 40% lower than the young adults exercising at the same relative intensity (P < 0.001). Average FFA R(a) in the elderly subjects was 35% higher than in the young adults exercising at the same absolute intensity (P < 0.05) but 35% lower than the young adults exercising at a similar relative intensity (P < 0.05). We conclude that fat oxidation is decreased while carbohydrate oxidation is increased during moderate intensity exercise in elderly men and women. The shift in substrate oxidation was caused by age-related changes in skeletal muscle respiratory capacity because lipolytic rates and FFA availability were not rate limiting in the older subjects.