Exercise Physiology Laboratory, Camilo José Cela University, Madrid, Spain.
Faculty of Health Sciences, Universidad Francisco de Vitoria, Pozuelo, Spain.
Eur J Nutr. 2020 Sep;59(6):2525-2534. doi: 10.1007/s00394-019-02100-7. Epub 2019 Nov 5.
Recent investigations have established that the ingestion of a moderate dose of caffeine (3-6 mg kg) can increase exercise and sports performance in women. However, it is unknown whether the ergogenicity of caffeine is similar during all phases of the menstrual cycle. The aim of this investigation was to determine the ergogenic effects of caffeine in three phases of the menstrual cycle.
Thirteen well-trained eumenorrheic triathletes (age = 31 ± 6 years; body mass = 58.6 ± 7.8 kg) participated in a double-blind, cross-over, randomised experimental trial. In the (1) early follicular (EF); (2) preovulation (PO); (3) and mid luteal (ML) phases, participants either ingested a placebo (cellulose) or 3 mg kg of caffeine in an opaque and unidentifiable capsule. After a 60-min wait for substance absorption, participants performed an incremental maximal cycle ergometer test until volitional fatigue (25 W/min) to assess peak aerobic cycling power (Wmax).
In comparison to the placebo, caffeine increased Wmax in the EF (4.13 ± 0.69 vs. 4.24 ± 0.71 W kg, Δ = 2.7 ± 3.3%, P = 0.01), in the PO (4.14 ± 0.70 vs. 4.27 ± 0.73 W kg, Δ = 3.3 ± 5.0%; P = 0.03) and in the ML (4.15 ± 0.69 vs. 4.29 ± 0.67 W kg, Δ = 3.6 ± 5.1%; P = 0.01) phases. The magnitude of the caffeine ergogenic effect was similar during all of the menstrual cycle phases (P = 0.85).
Caffeine increased peak aerobic cycling power in the early follicular, preovulatory, and mid luteal phases. Thus, the ingestion of 3 mg of caffeine per kg of body mass might be considered an ergogenic aid for eumenorrheic women during all three phases of the menstrual cycle.
最近的研究表明，摄入适量的咖啡因（3-6 毫克/千克）可以提高女性的运动表现。然而，目前尚不清楚咖啡因在月经周期的所有阶段是否具有同样的增强作用。本研究旨在确定咖啡因在月经周期三个阶段的作用。
13 名训练有素的月经正常的三项全能运动员（年龄=31±6 岁；体重=58.6±7.8 千克）参加了一项双盲、交叉、随机实验试验。在（1）卵泡早期（EF）；（2）排卵前（PO）；（3）和中期黄体（ML）阶段，参与者要么服用安慰剂（纤维素），要么服用 3 毫克/千克的咖啡因胶囊。在等待物质吸收 60 分钟后，参与者进行递增最大自行车测力计测试，直到自愿疲劳（25 W/min），以评估峰值有氧自行车功率（Wmax）。
与安慰剂相比，咖啡因增加了 EF（4.13±0.69 对 4.24±0.71 W/kg，Δ=2.7±3.3%，P=0.01）、PO（4.14±0.70 对 4.27±0.73 W/kg，Δ=3.3±5.0%，P=0.03）和 ML（4.15±0.69 对 4.29±0.67 W/kg，Δ=3.6±5.1%，P=0.01）期的 Wmax。在所有月经周期阶段，咖啡因的增强效果大小相似（P=0.85）。
咖啡因增加了卵泡早期、排卵前和中期黄体期的最大有氧自行车功率。因此，对于月经正常的女性，在月经周期的所有三个阶段，每公斤体重摄入 3 毫克的咖啡因可能被认为是一种增强运动表现的辅助手段。
