前言:負荷監控對運動員相當重要，這會影響訓練效果與傷害風險，目前尚未出現結合內外在負荷及網球專項特性的負荷指標。穿戴式裝置常被用於測量網球之擊球負荷，能夠辨別擊球動作及球速，但並沒有研究針對動作強度等擊球負荷指標做探討。目的: 1.探討隨著強度增加或疲勞累積時，外在負荷及運動表現與疲勞特徵的相關性。2.觀察擊球表現隨負荷漸增的變化。方法：十二名受試者配戴心率帶、Zepp2 sensor和IMU進行網球專項耐力測試，每分鐘增加送球頻率並詢問RPE分數，至受試者力竭則停止測試。結果: PlayerLoad與內在負荷指標皆呈現顯著相關，其中HRR%(r = 0.605)、RPE(r = 0.639)、TRIMP值(r = 0.481)、平均HR(r = 0.602)，皆呈現中度相關; 擊球負荷(Hitting Load)與內在負荷皆呈現顯著相關，其中RPE(r = 0.508)呈現中度相關，HRR%(r = 0.365)、TRIMP值(r = 0.276)、平均HR(r = 0.367)則呈現弱相關。結論: PlayerLoad和擊球負荷能實際應用在實際網球訓練中，且對比與單一外在負荷指標，運動表現參數以迴歸公式計算後有更佳的相關性，透過這些方法，能提升未來外在負荷指標應用於網球運動上的可能性。

Introduction: Load monitoring holds significant importance for athletes, as it is highly related to training outcomes and injury risks. Wearable devices are frequently utilized to measure the hitting load in tennis to distinguish different stroke motion and measure ball speed, however research addressing indicators of hitting load and other factors, remains scarce. Purpose: 1. Investigate the correlation between external loads, sports performance, fatigue characteristics, as exercise intensity increases or fatigue accumulates. 2. Understand the variations in hitting performance as the load graded increases. Method: Twelve subjects underwent a tennis-specific wearing heart rate monitor, Zepp2 and IMU sensor, ball delivery frequency increases every minute and asking for RPE scores until exhaustion occurred. Results: Both PlayerLoad and internal Load shows significant correlations, including HRR% (r = 0.605), RPE (r = 0.639), TRIMP value (r = 0.481), and average HR (r = 0.602). RPE (r = 0.508) exhibited moderate correlation, while HRR% (r = 0.365), TRIMP (r = 0.276), and average HR (r = 0.367) showed a weak correlation. Conclusion: PlayerLoad and Hitting Load are valuable for real tennis training. They show stronger correlations with sport performance parameters when compared to single external load indicators, thanks to regression formulas. These methods bolster the potential for future use of external load indicators in tennis training.

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