運動前攝取咖啡因對心臟自律神經之影響
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2007
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Abstract
目的：本研究的目的是探討運動前攝取咖啡因，對於安靜、運動、恢復狀態的心臟自律神經系統造成的影響。方法：受試者為11位健康的男性（年齡：24.8 ± 1.6歲、身高：175.0 ± 4.9公分、體重：70.7 ± 6.0公斤），採重複量數的雙盲實驗設計，排空期為3天，以平衡次序原則分別攝取6mg/kg的咖啡因或安慰劑，60分鐘後進行60%VO2max的運動30分鐘，恢復期為10分鐘。以重複量數二因子變異數 ( 2-way ANOVA ) 分析五個不同時間點（運動前、運動初期、運動中期、運動末期、恢復期）咖啡因與安慰劑兩組之間心率變異性的差異，以相依樣本t考驗咖啡因對於血壓、警覺度 ( alertness visual analog scale, AVAS ) 與運動強度自覺程度 ( rating of perceived exertion, RPE ) 的影響，顯著水準為p<.05。結果：運動前，咖啡因組的LF功率值 ( +121.9% ) 與LF% ( +46.1% ) 顯著增加，收縮壓 ( +7.7% ) 、舒張壓 ( +8.4% ) 以及AVAS ( +16.7%) 均顯著高於安慰劑組 ( p<.05 )。運動過程中，咖啡因組在運動初期的HF% ( +83.6% )顯著高於安慰劑組 ( p<.05 )。在運動中期的VLF功率值 ( +53.5% ) 、LF 功率值( +60% ) 以及總功率 ( +54.3% ) 顯著提高 ( p<.05 )，運動末期的LF功率值 ( +45% ) 也顯著高於安慰劑組 ( p<.05 )。恢復期的舒張壓 ( +7.1% ) 與AVAS ( +7.9% ) 顯著高於安慰劑組 ( p<.05 )。結論：單次攝取咖啡因會顯著提高休息時交感神經系統活性，使警覺度及血壓增加。在30分鐘中等強度運動過程中，咖啡因一樣會使交感神經活性較佔優勢。但在恢復期，咖啡因所提高的亢奮性，可能造成恢復期的各項變項恢復較慢。
Purpose: To investigate the effects of caffeine ingestion before exercise on cardiac autonomic nervous systems at rest, during exercise, and recovery. Methods: Subjects were 11 healthy male volunteers (age: 24.8 ± 1.6 yr, hight: 175.0 ± 4.9 cm, weight: 70.7 ± 6.0 kg). A double-blind repeated-measures design was used for the experiment. The testing order was counter-balanced with a 3-day washout period. Placebo or caffeine (6mg/kg) capsules were ingested 60 minutes before cycling on an ergometer for 30 minutes. The exercise intensity was at 60% of VO2max, and the recovery phase was 10 minutes. The effects of time and treatment were evaluated using a repeated-measures 2-way ANOVA to compare the heart rate variability between the trials at different phase (before exercise, primary phase, middle phase, last phase, and the recovery phase ). Student’s paired t-test was used for blood pressure ( BP ), alertness visual analog scale ( AVAS ) , and rating of perceived exertion ( RPE ). A p values of less than .05 were considered to be statistically significant. Data are expressed as mean ± SEM. Results: Before exercise the LF value ( +121.9% ), LF% ( +46.1% ), systolic pressure ( +7.7% ), diastolic pressure ( +8.4% ), and AVAS ( +16.7% ) were significantly increased for caffeine ingestion ( p<.05 ). During exercise, the HF% ( +83.6% ) of caffeine ingestion at the primary phase of exercise was significantly increased ( p<.05 ). The VLF value ( +53.5% ), LF value ( +60% ), and total power ( +54.3% ) were significantly higher at middle phase of exercise ( p<.05 ). The LF value ( +45% ) was significantly enhanced at last phase of exercise ( p<.05 ). The diastolic pressure ( +7.1% ) and AVAS ( +7.9% ) was significantly higher than placebo at the recovery phase ( p<.05 ). Conclusion: Acute caffeine ingestion can activate the sympathetic nervous system activity (SNSA), increase the alertness and BP at rest. During 30 min medium intensity exercise, the SNSA was more dominant for caffeine ingestion. However, the SNSA stimulation may also slow the recovery phase.
Purpose: To investigate the effects of caffeine ingestion before exercise on cardiac autonomic nervous systems at rest, during exercise, and recovery. Methods: Subjects were 11 healthy male volunteers (age: 24.8 ± 1.6 yr, hight: 175.0 ± 4.9 cm, weight: 70.7 ± 6.0 kg). A double-blind repeated-measures design was used for the experiment. The testing order was counter-balanced with a 3-day washout period. Placebo or caffeine (6mg/kg) capsules were ingested 60 minutes before cycling on an ergometer for 30 minutes. The exercise intensity was at 60% of VO2max, and the recovery phase was 10 minutes. The effects of time and treatment were evaluated using a repeated-measures 2-way ANOVA to compare the heart rate variability between the trials at different phase (before exercise, primary phase, middle phase, last phase, and the recovery phase ). Student’s paired t-test was used for blood pressure ( BP ), alertness visual analog scale ( AVAS ) , and rating of perceived exertion ( RPE ). A p values of less than .05 were considered to be statistically significant. Data are expressed as mean ± SEM. Results: Before exercise the LF value ( +121.9% ), LF% ( +46.1% ), systolic pressure ( +7.7% ), diastolic pressure ( +8.4% ), and AVAS ( +16.7% ) were significantly increased for caffeine ingestion ( p<.05 ). During exercise, the HF% ( +83.6% ) of caffeine ingestion at the primary phase of exercise was significantly increased ( p<.05 ). The VLF value ( +53.5% ), LF value ( +60% ), and total power ( +54.3% ) were significantly higher at middle phase of exercise ( p<.05 ). The LF value ( +45% ) was significantly enhanced at last phase of exercise ( p<.05 ). The diastolic pressure ( +7.1% ) and AVAS ( +7.9% ) was significantly higher than placebo at the recovery phase ( p<.05 ). Conclusion: Acute caffeine ingestion can activate the sympathetic nervous system activity (SNSA), increase the alertness and BP at rest. During 30 min medium intensity exercise, the SNSA was more dominant for caffeine ingestion. However, the SNSA stimulation may also slow the recovery phase.
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咖啡因, 運動, 心率變異性, 心臟自律神經, caffeine, exercise, heart rate variability, cardiac autonomic nervous systems