Nielsen A N, Mizuno M, Ratkevicius A, Mohr T, Rohde M, Mortensen S A, Quistorff B
The Copenhagen Muscle Research Center, Department of Medical Biochemistry and Genetics, University of Copenhagen, Denmark.
Int J Sports Med. 1999 Apr;20(3):154-8. doi: 10.1055/s-2007-971110.
A double-blind placebo-controlled cross-over trial was undertaken to evaluate the effect of antioxidant supplementation on maximal oxygen uptake during bicycling, 31-phosphorus nuclear magnetic response spectroscopy (31P-NMRS) detected muscle energy metabolism during plantar flexion and muscle fatigue evaluated by 1-s electrical stimulation at low (10 Hz) and high (50 Hz) frequency. Seven male triathletes received daily oral antioxidant supplementation in capsule form including 100 mg coenzyme Q10 (CoQ10), 600 mg ascorbic acid and 270 mg alpha-tocopherol or placebo over a 6-week interval. Serum concentration of CoQ10 was significantly higher in the antioxidant phase (1.80+/-1 microg x ml(-1), mean +/- SD) than control (0.9+/-0.21 microg ml(-1)) or placebo phase (0.9+/-0.3 microg x ml(-1)) (P<0.01). Maximal oxygen uptake was 63.8+/-3.0 ml x min(-1) x kg(-1) in the control phase, and did not change significantly in the antioxidant (67.6+/-10.8 ml x min(-1) x kg(-1)) or the placebo phase (61.9+/-4.5 ml x min(-1) x kg(-1)). The combined 31P-NMRS/low frequency fatigue test (plantar flexion of the foot) did not show differences in the gastrocnemius muscle pH (6.77+/-0.14), phosphocreatine reduction at the end of exercise (23+/-14% of rest) and half-time for recovery of phosphocreatine (33+/-12 sec) between the placebo and the antioxidant trial. No difference in muscle fatigue at 10 Hz electrical stimulation was found between the three phases. In conclusion, the results demonstrate no effect of antioxidative vitamin supplementation on maximal oxygen uptake, muscle energy metabolism or muscle fatigue in triathletes.
进行了一项双盲安慰剂对照交叉试验,以评估补充抗氧化剂对骑行过程中最大摄氧量的影响,用31-磷核磁共振波谱法(31P-NMRS)检测跖屈过程中的肌肉能量代谢,并通过低频率(10Hz)和高频率(50Hz)的1秒电刺激评估肌肉疲劳。7名男性铁人三项运动员在6周的时间里每天口服胶囊形式的抗氧化剂补充剂,其中包括100mg辅酶Q10(CoQ10)、600mg抗坏血酸和270mgα-生育酚,或服用安慰剂。抗氧化剂阶段的CoQ10血清浓度(1.80±1μg·ml-1,平均值±标准差)显著高于对照阶段(0.9±0.21μg·ml-1)或安慰剂阶段(0.9±0.3μg·ml-1)(P<0.01)。对照阶段的最大摄氧量为63.8±3.0ml·min-1·kg-1,在抗氧化剂阶段(67.6±10.8ml·min-1·kg-1)或安慰剂阶段(61.9±4.5ml·min-1·kg-1)没有显著变化。联合31P-NMRS/低频疲劳试验(足部跖屈)在安慰剂试验和抗氧化剂试验之间,腓肠肌pH值(6.77±0.14)、运动结束时磷酸肌酸减少量(休息时的23±14%)和磷酸肌酸恢复半衰期(33±12秒)没有差异。在三个阶段之间,10Hz电刺激下的肌肉疲劳没有差异。总之,结果表明补充抗氧化维生素对铁人三项运动员的最大摄氧量、肌肉能量代谢或肌肉疲劳没有影响。