運動與肥胖專論

Exercise and Obesity

郭家驊(Chia-Hua Kuo) ； 陳九州(Jyh-Jung Chen) ； 陳志中(Chiu-Chou Chen)

《北體學報》 7期 (2000/04) Pp. 180-192

https://doi.org/10.6167/TPEC/2000.7.15

摘要

肥胖（特指腹圍脂肪增加者）被認為是大部分慢性疾病的重要導因。與肥胖相關的疾病，佔工業化國家所有死因的75%（佔臺灣十大死因的50%以上），成為許多國家醫療資源極大的負擔。現代醫藥對肥胖所衍生出來的慢性疾病均束手無策，運動與飲食控制，為兩種目前最常用的減肥策略。過度節食減肥易使肌肉與肝臓肝醣儲存量降低，導致維持血糖的能力大打折扣，因而應付環境壓力的能力降低，同時造成血液酮體濃度增加。血糖降低導致免疫及神經細胞能量供給不足，以致於抵抗力低與精神萎靡。另外為補償維持體內血糖濃度的能力，肌肉（骨骼肌）蛋白必須分解出氨基酸，提供作為糖質新生作用。長期運動為健康且自然的一種減肥方式，運動除可避免上述節食減肥造成的缺點，研究證明有規律運動的人，除了免疫能力較強、肝醣儲存較多外（身體儲備更多可被快速使用的能量物質），身體組成可以逐漸改變使肌肉質量增加與脂肪質量減少。運動雖然增加身體能量支出，但並不會因此增加食慾。運動減低脂的主要原因，至少包括下列兩項：1)運動可使肌肉血流量增加數倍，造成攜帶養份的血液流向肌肉較多，對脂肪細胞的養份補給相對減少；2)運動後脂肪組織lipoprotein lipase (LPL)的活性減少且LPL在肌肉組織的活性增加，此效應也使得血液輸送的三酸甘油脂，較易進入肌肉且不易進入脂肪織儲存。長期耐力性運動，可使所訓練的肌肉粒腺體數目增加。此結果可使得肌肉對於脂肪的燃燒能力增加。因此可藉由長期規律運動，來限制脂肪細胞的成長。運動減肥可以藉由消耗熱量，達到減肥效果為目前一般的大衆理論。雖然運動可以達到減肥效果，但由於運動所消耗的熱量非常有限，不足以解釋運動減肥的效果。

並列摘要

Obesity has been considered as a major cause of most age-onset diseases. Obesity-related diseases account for 75% of mortality in the western industrialized countries (more than 50% in Taiwan). A great deal of national resources in health care has been consumed to encounter these diseases. However, no effective medical strategy was developed for the disease control. Apparently, exercise and diet are common ways to attenuate these obese-related health problems. Dietary restriction without physical activity sometime can lead to poor control of plasma glucose level, which will in turn reduced the capability for stress management against environment. Additionally, plasma ketone body concentration may also be elevated. It is known that the nervous system and the blood cell including immune cell almost exclusively use carbohydrates as the energy source. These phenomena are most likely due to the consequences of inadequate of liver and muscle glycogen storage. Under these circumstances, muscle protein has to be degraded in order to provide precursor for gluconeogenesis. Regular exercise seems to be the ultimate choice for weight controlling. It can prevent the disadvantage as previously mentioned, but also increase glycogen storage and boost immune function in the body. Furthermore, exercise has no effect on appetite. There are several mechanisms that can explain why exercise can reduce body fat: 1) Exercise increases muscle blood flow and, therefore, reduced blood flow in adipose tissue. This will lead to the nutrient redistribution. 2) Exercise can increase muscle LPL (lipoprotein lipase) activity and reduce that in adipose tissue. This will reduce triglycerides being uptake by adipose tissue. Regular exercise increase the muscle mitochondria numbers. The result can increase body capability of fat utilization. Therefore, regular exercise can effectively restrict fat cell growth. Exercise can reduce body fat via energy consumption during muscular contraction per se, are most likely a false concept. In fact, the energy consumed during heavy exercise is to small to explain the fat burning.