DSpace community: 運動科學研究所

低氧環境對耐力運動表現及認知功能之影響：探討相關生理機制與營養增補策略

title: 低氧環境對耐力運動表現及認知功能之影響：探討相關生理機制與營養增補策略 abstract: 低氧環境使空氣的氧分壓降低，促使體內組織使用氧氣能力下降，中樞及周邊疲勞也較海平面來的更高。雖然，目前已知在高海拔從事耐力運動，會讓身體面對低氧環境，無法發揮正常生理機能而降低運動表現，同時，氧氣壓力減少會導致大腦動脈局部產生組織缺氧，降低認知功能、訊息處理注意力功能以及反應時間增加等，進而影響運動中各種判斷能力上的表現。在眾多高強度耐力運動競技項目，競賽過程需要大腦認知功能去處理臨場反應，判斷各種戰術情境與環境因素等策略，做出對比賽當下最有利的決定，因此每個階段都是勝負的關鍵。例如：鐵人三項運動，其中在自行車項目，利用選手組成集團可以減低風阻效應來達成比賽策略，藉此保留體能進而提升最後一項跑步的表現。然而，在低氧環境進行耐力運動競賽，生理機能會受到更大的挑戰，造成體能上的負擔，而大腦也需要不停判斷、比賽配速、策略及多個運動項目的轉換等問題，且大腦前額葉血流狀態與競賽時所需的認知、思考及判斷有高度相關性，此外前額葉皮層減少氧合作用與降低肌肉力量有關連性，更近一步影響動作控制及判斷能力等問題。目前學界在低氧對腦部血流調控與認知功能之影響仍尚未十分清楚；此外，適當營養增補是否具有改善低氧降低運動表現的正面效益及認知功能，亦是值得進一步深入探討的方向之一。

複合式訓練對擊劍運動員下肢等速肌力之影響

title: 複合式訓練對擊劍運動員下肢等速肌力之影響 abstract: 本研究目的在探討5週先重量後增強與先增強後重量之複合式訓練順序對下肢肌力之影響。以33名的高中擊劍運動員為研究對象，隨機分成重量訓練（weight training，以下簡稱W）+增強式訓練（plyometric training，以下簡稱P）組（先實施W，再實施P）及P+W組（先實施P後，再實施W）兩組，展開為期5週之訓練計畫，依組別分別進行每週3次，每次60分鐘之複合式訓練，並融入訓練計畫中。研究結果顯示在P+W跟W+P兩組膝關節60°/s的慣用腳屈肌的峰力矩、相對峰力矩、平均功率及平均力矩均達到顯著差異。伸肌峰力矩、相對峰力矩、平均功率及平均力矩亦達到顯著差異。在60°/s的非慣用腳屈肌及伸肌，未達到顯著差異。P+W跟W+P兩組膝關節180°/s之慣用腳及非慣用腳屈、伸肌，除180°/s慣用腳總作功量及平均力矩經訓練後達到顯著差異，其餘皆未達到顯著差異。本研究結論：先增強後重量之複合式訓練順序，較能有效提升慣用腳在60°/s能顯著增加下肢等速膝屈肌最大力矩，建議可將複合式訓練應用於擊劍項目之肌力與體能訓練，藉以增強擊劍長刺技術時小腿前跨帶動及後腿負重推蹬力量。

Resveratrol increases stem cell function in the treatment of damaged pancreas

title: Resveratrol increases stem cell function in the treatment of damaged pancreas abstract: Pancreatic damage results in insufficient insulin secretion, leading to type 1 diabetes. Stem cell-based therapy has recently shown potential in the treatment of type 1 diabetes. Resveratrol supplementation has demonstrated a beneficial effect in treating diabetes. This study investigates if adipose-derived stem cells (ADSC), preconditioned with resveratrol, show better effects on experimental diabetic animals. Wistar rats were randomly divided into four groups including sham (normal rats), DM (diabetic rats induced by SZT injection), DM+ADSC (DM rats with receiving autologous ADSC transplantation) and DM+R-ADSC (DM rats receiving resveratrol preconditioned ADSC). The experimental results show that SZT induced pancreatic damage (DM group), including reduction of islet size, fibrosis pathway activation, survival signaling suppression, and apoptotic pathway expression, lead to serum glucose elevation. Autologous ADSC (DM+ADSC group) transplantation shows improvement in the above observations in DM rats. Furthermore, ADSC precondition with resveratrol (DM+R-ADSC group) reveals significant improvement in the above pathological observations over both DM and DM+ADSC groups. We found that ADSC precondition with resveratrol increases the survival marker p-Akt expression, leading to enhanced ADSC viability. This study suggests that ADSC precondition with resveratrol shows potential in the treatment of patients with type 1 DM.

Twelve-weeks protocatechuic acid administration improves insulininduced and insulin-like growth factor-1-induced vasorelaxation and antioxidant activities in aging spontaneously hypertensive rats

title: Twelve-weeks protocatechuic acid administration improves insulininduced and insulin-like growth factor-1-induced vasorelaxation and antioxidant activities in aging spontaneously hypertensive rats abstract: Protocatechuic acid (PCA), a strong antioxidant, has been reported for its cardiovascular-protective effects. This study aimed to investigate the effects of PCA administration on vascular endothelial function, mediated by insulin and insulin-like growth factor-1 (IGF-1), and antioxidant activities in aging hypertension. Thirty-six-week-old male aging spontaneously hypertensive rats were randomly divided into vehicle control (SHR) and PCA (SHR+PCA) groups, while age-matched Wistar–Kyoto rats (WKY) served as the normotensive vehicle control group. The oral PCA (200 mg/kg/day) was administered daily for a total of 12 weeks. When the rats reached the age of 48 weeks, the rat aortas were isolated for the evaluation of vascular reactivity and Western blotting. Also, nitric oxide (NO) production and antioxidant activities were examined among the three groups. The results showed that, when compared with the SHR group, the insulin-induced and IGF-1-induced vasorelaxation were significantly improved in the SHR+PCA group. There was no significant difference in the endothelium-denuded vessels among the three groups. After the pre-incubation of phosphatidylinositol 3-kinase (PI3K) or NO synthase (NOS) inhibitors, the vasorelaxation was abolished and comparable among the three groups. The protein levels of insulin receptors, IGF-1 receptors, phospho-protein kinase B (p-Akt)/Akt, and phospho-endothelial NOS (p-eNOS)/eNOS in aortic tissues were significantly enhanced in the SHR+PCA group when compared with the SHR group. Moreover, significant improvements of nitrate/nitrite concentration and antioxidant activities, including superoxide dismutase, catalase, and total antioxidants, were also found in the SHR+PCA group. In conclusion, the 12 weeks of PCA administration remarkably improved the endothelium-dependent vasorelaxation induced by insulin and IGF-1 in aging hypertension through enhancing the PI3K–NOS–NO pathway. Furthermore, the enhanced antioxidant activities partly contributed to the improved vasorelaxation.