研究目的：探討優秀大專女壘投手於長時間反覆投球，疲勞後對於投球球速及控球能力的影響。研究方法：招募七名大專女子壘球投手，透過每局15顆快速直球，最多10局的模擬比賽來誘發疲勞；分析疲勞前、後的投球球速、好球率與誤差目標距離表現，透過無母數統計相依樣本z檢定考驗，疲勞前、後表現的差異。研究結果顯示：首兩局的球速為54.53 ± 2.21英哩/小時、好球率為59.05 ± 16.97%、誤差距離為21.91±1.83公分，大部分投手經投擲約8局，投球數約120顆達到疲勞，疲勞後球速顯著下降為52.90 ± 2.19英哩/小時，誤差距離也顯著增加至31.53±0.40公分。研究結論：誘發性疲勞確實造成投球球速與控球能力會顯著衰退，尤其是控球能力。建議壘球教練及選手，未來可透過監控投球數量或觀察球速或控球來了解投手疲勞情況。

The purpose of this study was to investigate the effect of subjective fatigue on ball velocity and control ability after long-time repeated pitching among women’s softball pitchers. 7 elite college female softball pitchers were recruited to perform a simulated game consisting of 15 fastball pitches per inning up to 10 innings to approach subjective fatigue. Ball velocity, strike ratio and error distance per inning were analyzed. Difference of pitching performance between pre and post subjective fatigue was analyzed using dependent sample z test of nonparametric statistics. Performance of first two innings was shown that the ball velocity was 54.53 ± 2.21 mile/hr, pitching accuracy ratio was 59.05 ± 16.97%, and error distance was 21.91±1.83 cm. Most pitchers felt fatigue after pitching 8 innings, the pitching counts were 120. The ball velocity was drop to 52.90 ± 2.19 mile/hr with significance, and the error distance was significant lager to 31.53±0.40 cm. The conclusion of this study was that ball velocity and control ability were a downward trend with increase of pitching innings. Suggest the softball coaches and players could monitoring the pitching count, or observation pitching accuracy to determine the status of pitcher fatigue. There will be a recommendation for softball coaches and players, we could observe pitcher’s fatigue condition through monitoring pitching counts and control ability.