攝取不同劑量咖啡因對半蹲舉運動表現之影響

Abstract

目的：探討增補不同劑量咖啡因，對半蹲舉運動表現與動力學指標之影響。方法：招募12名有阻力訓練經驗男性。受試者於半蹲舉運動前60分鐘以隨機平衡次序之方式接受三種不同實驗處理，包括3 mg/kg咖啡因膠囊 (CAF3)、6 mg/kg咖啡因膠囊 (CAF6) 與安慰劑膠囊 (PLA)。在每次實驗處理後，受試者需在測力板上進行4組半蹲舉測驗，負荷設定為70% 1 RM (repetition maximum)，並於第4組半蹲舉測驗中，要求受試者盡可能多地實施半蹲舉運動至衰竭。蒐集實驗過程前、中與後的運動自覺量強度 (rating of perceived exertion, RPE) 及疼痛自覺程度 (visual analog scale, VAS)，並計算半蹲舉第4組的反覆次數和訓練量，以及計算每組力量、功率、速度的最大值與平均值，以及平均力量與速度的遞減率指標。結果：在半蹲舉測驗平均速度，CAF6顯著高於PLA (CAF6 vs. PLA, 第一組: 0.49 ± 0.06 vs. 0.46 ± 0.08 m/s, 第二組: 0.48 ± 0.08 vs. 0.45 ± 0.07 m/s, 第三組: 0.49 ± 0.06 vs. 0.44 ± 0.08 m/s, 第四組: 0.48 ± 0.07 vs. 0.44 ± 0.07 m/s, p< .05)。在第1至3組最大力量遞減率，CAF6顯著低於CAF3 (CAF6 vs. CAF3, 第一組: 3.90 ± 2.92 vs. 16.45 ± 16.15 %, 第二組: 3.53 ± 1.89 vs. 5.66 ± 6.77 %, 第三組: 3.64 ± 1.43 vs. 7.64 ± 8.98 %, p < .05)。在第1至3組最大功率遞減率，CAF6顯著低於CAF3 (CAF6 vs. CAF3, 第一組: 7.12 ± 2.09 vs. 19.15 ± 16.43 %, 第二組: 6.86 ± 2.54 vs. 8.87 ± 5.33 %, 第三組: 6.71 ± 1.88 vs. 12.42 ± 11.82 %, p < .05)。此外，在半蹲舉時的反覆次數、訓練量、力量、功率、最大速度、RPE和VAS，在3種處理之間均無顯著差異。 結論：不同劑量咖啡因可能無法改善半蹲舉運動的反覆次數和訓練量，不過，6 mg/kg咖啡因可能提升半蹲舉的平均速度，並延緩最大力量與最大功率流失的效果。

Purpose: To investigate the effect of different doses of caffeine on half-squat perfor-mance and kinetic variables.Methods: Twelve resistance-trained males performed half-squats under three conditions: 3 mg/kg caffeine capsules (CAF3), 6 mg/kg caffeine capsules (CAF6), and placebo (PLA) cap-sules, administered 60 minutes before exercise in a randomized order. Participants per-formed 4 sets of half-squat on the force platform with a load set at 70% of one repetition maximum. At the fourth set of half-squat, participants were asked to perform as many repeti-tions as possible until failure. The rating of perceived exertion (RPE) and visual analog scale (VAS) for muscle pain were measured before, during, and after each trial. The number of repetitions and exercise volume of the 4th set were calculated. The peak and mean force, ve-locity, power, and performance decrement scores of mean force and velocity were also cal-culated.Results: The average half-squat velocity in the CAF6 was significantly higher than in the PLA (CAF6 vs. PLA, SET1: 0.49 ± 0.06 vs. 0.46 ± 0.08 m/s, SET2: 0.48 ± 0.08 vs. 0.45 ± 0.07 m/s, SET3: 0.49 ± 0.06 vs. 0.44 ± 0.08 m/s, SET4: 0.48 ± 0.07 vs. 0.44 ± 0.07 m/s, p< .05). The decrement rate of maximum force in the 1st to 3rd sets was significantly lower in CAF6 compared to CAF3 (CAF6 vs. CAF3, SET1: 3.90 ± 2.92 vs. 16.45 ± 16.15 %, SET2: 3.53 ± 1.89 vs. 5.66 ± 6.77 %, SET3: 3.64 ± 1.43 vs. 7.64 ± 8.98 %, p < .05). Similarly, the decrement rate of maximum power in the 1st to 3rd sets was significantly lower in CAF6 compared to CAF3 (CAF6 vs. CAF3, SET1: 7.12 ± 2.09 vs. 19.15 ± 16.43 %, SET2: 6.86 ± 2.54 vs. 8.87 ± 5.33 %, SET3: 6.71 ± 1.88 vs. 12.42 ± 11.82 %, p < .05). However, no signifi-cant differences were found among treatments in repetitions, training volume, force, power, maximum velocity, RPE, and VAS. Conclusion: Different doses of caffeine might not improve half-squat repetitions and vol-ume, however, CAF6 might increase half-squat velocity and prevent the decline in maximal strength and power.