[[alternative]]Changes in Electrodermal Activity in College Females Following 6-weeks of Walking Training

[[abstract]] 背景：中等強度的步行對於個人健康與體能有正面的助益，對於自律神經也有助於其平衡。大多數的研究利用心跳變異率來探討步行與自律神經之關聯。此研究利用皮膚導電度的變化探討六周的步行練習對於交感神經的影響。 實驗步驟：47名大學在學女性(平均年齡21.15±0.91，平均BMI 19.71±1.78)，平時無運動習慣。其中22位被隨機選入步行組，另外25位屬於控制組。步行組須在跑步機上進行每次三十分鐘、每周三次，合計六周的步行訓練，速度依個人的運動自覺強度(rating of perceived exertion,RPE)而定。步行組參與者每隔兩週接受一次良導絡檢測，其中17位並於3個月後返校接受測量。六週實驗的前後並且記錄下受測者的BMI、體脂率、腰臀比。25位對照組基本上依照相同檢驗流程，但不進行步行訓練。 結果： 實驗發現，步行組組內的平均皮膚電導值在實驗進行2週後即有明顯增加；與對照組比較，六週實驗後也有顯著性差異。而且，上肢的平均電導值遠大於下肢(p=0.011)，經過六週步行訓練後所增加的幅度也較大。此一變化具可逆性，三個月後追蹤測量時，皮膚電導值已與基礎值無差異(p=0.993)。 結論：研究發現經過兩周步行後，皮膚導電度有明顯之增加，持續的運動可以維持皮膚導電度的增加直至六周實驗結束。步行中斷後三個月，皮膚導電度回復至實驗前之水平。皮膚導電度的增加與身體質量指數並無相關。在實際應用上，皮膚導電度的變化或許可以做為衡量體能的新指標。[[abstract]] BACKGROUND: Moderate intensity walk is beneficial to individual health and to improve physical fitness by balancing autonomic nervous system, which is found to be a major advantage to cardiovascular system. Most studies used heart rate variability (HRV) as the tool to study the relationship of walk exercise and the autonomic nervous system. This study, using a Ryodoraku device as the tool, investigated the changes in electrodermal activity (EDA) after 6-week walk. METHOD: Forty seven young females (mean age ±SD is 21.15±0.91) with average BMI of 19.71±1.78, and did not exercise regularily were recruited into this study. 22 of them were randomly chosen as the walk group, and the other 25, the control group. Walk group was asked to walk on a treadmill 3 times a week, 30 minutes each time for 6 weeks. The walking speeds were assigned according to individual rating of perceived exertion (RPE). The electrical conductances of the 24 Ryodoraku points were recorded by a Ryodoraku device every 2 weeks since the beginning of the experiment. 17 of the 22 participants returned 3 months later and were measured again. The BMI, body fatness, and waist-hip ratio were also checked before and after the experiment. The control group was measured following a similar protocol but without walk exercise. RESULTS: The within-subject averages of the skin conductance are significantly higher since 2 weeks after the execise started. The between-subject averages show significant difference at the end of 6-week exercise. This study also found the skin conductance of the upper limbs is significantly higher (p=0.011), and increase more after the 6 weeks training. This change is reversible and was found back to its baseline 3 months after the exercise stopped. CONCLUSIONS: Our study finds significant increase in skin conductance after 2 weeks of training. Continuing exercise sustains this level for at least 6 weeks, but would back to its baseline 3 months after withdrawal of exercise. The change of electrical conductance is unlikely BMI related, and may be used as an indicator of physical fitness