不同體位大學生身體質量指數與爆發力之關係

The relationships between BMI and explosive strength for different weightstatus university students

緒論：本研究企圖使用國內某大學所收集的一批大學生縱貫資料，以一種比較創新的統計技術來探討正常／過重／肥胖體位大學生其身體質量指數（body mass index, BMI）與爆發力之間的關係，並且探討性別在這些關係上的交互作用效果。方法:使用結構方程模式的方法學設計我們稱為隨機係數自迴歸模式（random-intercept autoregressive model, RIAM），來檢定個人間BMI與個人間爆發力關係、個人內BMI與個人內爆發力關係、個人內BMI自迴歸關係以及個人內爆發力自迴歸關係。使用多群體模式檢定性別的交互作用效果。四個波段的樣本，參與者共3126位。男生1661位，女生1465位。結果：正常／過重／肥胖群大學生的個人間BMI越高，個人間爆發力的表現也越差。男女生具有交互作用效果，個人間BMI對個人間爆發力的效果，男生顯著地大於女生。個人內BMI與個人內爆發力也是顯著的負向影響，男女生不具交互作用，代表這個影響關係男女等同。個人內BMI的自迴歸顯著，男女生不具交互作用，表示個人內BMI具有延滯效果，此效果男女等同。個人內爆發力自迴歸則是男女等同，不具顯著性。結論：本研究提供了一個新的方法來檢定BMI與體適能的關係，新的發現也讓我們有新的視野來審視BMI與爆發力的關係，增進我們對BMI與爆發力之間的運作機制的理解。

Introduction: This four-wave longitudinal study used an innovative statistical technique to examine the association between BMI and explosive strength for normal/overweight/obese students of a university in Taiwan. The interaction effects of genderon the relationship were also evaluated. Methods: This study involved 3216 student participants, of which 1661 were men and 1465 were women. Structural equation modeling was used to design a random-intercept autoregressive model, which was applied to examine the association of between-person BMI and between-person explosive strength; and within-person BMI and within-person explosive strength. Theautoregessions of within-person BMI, and within-person explosive strength were also examined. A multiple group model was used to evaluate the interaction effect of gender. Results: A higher between-person BMI in normal/overweight/obese students was correlated with a lower performance of between-person explosive strength. Gender had an interaction effect on this association: there was a larger negative correlation in men than women. There was a significant negative correlation between within-person BMI and within-person explosive strength, which did not differbetween men and women. The autoregression of within-person BMI was significantly positive, and this carry-over effect for within-person BMI occurred to the same extent in both men and women. The autogressive effect of within-person explosive strength was the same for men and women, and not significant. Conclusion: The significant correlations between BMI and explosive strength identified from the application of an innovative statistical technique provide new perspectives for researchers investigating these relationships. These results enhanceour understanding of the operational mechanisms between BMI and explosive strength.