Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Byrom Street, Liverpool, L3 3AF, UK.
Institute of Sport, University of Chichester, Chichester, UK.
Eur J Appl Physiol. 2018 Jun;118(6):1265-1272. doi: 10.1007/s00421-018-3858-3. Epub 2018 Apr 4.
New Zealand blackcurrant (NZBC) extract has previously been shown to increase fat oxidation during prolonged exercise, but this observation is limited to males. We examined whether NZBC intake also increases fat oxidation during prolonged exercise in females, and whether this was related to greater concentrations of circulating fatty acids.
In a randomised, crossover, double-blind design, 16 endurance-trained females (age: 28 ± 8 years, BMI: 21.3 ± 2.1 kg·m, VO: 43.7 ± 1.1 ml·kg·min) ingested 600 mg·day NZBC extract (CurraNZ) or placebo (600 mg·day microcrystalline cellulose) for 7 days. On day 7, participants performed 120 min cycling at 65% VO, using online expired air sampling with blood samples collected at baseline and at 15 min intervals throughout exercise for analysis of glucose, NEFA and glycerol.
NZBC extract increased mean fat oxidation by 27% during 120 min moderate-intensity cycling compared to placebo (P = 0.042), and mean carbohydrate oxidation tended to be lower (P = 0.063). Pre-exercise, plasma NEFA (P = 0.034) and glycerol (P = 0.051) concentrations were greater following NZBC intake, although there was no difference between conditions in the exercise-induced increase in plasma NEFA and glycerol concentrations (P > 0.05). Mean fat oxidation during exercise was moderately associated with pre-exercise plasma NEFA concentrations (r = 0.45, P = 0.016).
Intake of NZBC extract for 7 days elevated resting concentrations of plasma NEFA and glycerol, indicative of higher lipolytic rates, and this may underpin the observed increase in fat oxidation during prolonged cycling in endurance-trained females.
新西兰黑加仑（NZBC）提取物先前已被证明可在长时间运动中增加脂肪氧化，但这一观察结果仅限于男性。我们研究了 NZBC 摄入是否也能在女性长时间运动中增加脂肪氧化，以及这是否与循环脂肪酸浓度的增加有关。
在一项随机、交叉、双盲设计中，16 名耐力训练的女性（年龄：28±8 岁，BMI：21.3±2.1 kg·m，VO₂：43.7±1.1 ml·kg·min）分别摄入 600mg·天 NZBC 提取物（CurraNZ）或安慰剂（600mg·天微晶纤维素）7 天。在第 7 天，参与者以 65%VO₂进行 120 分钟的自行车运动，使用在线呼出空气采样，在基线和运动期间每隔 15 分钟采集一次血液样本，用于分析血糖、非酯化脂肪酸（NEFA）和甘油。
与安慰剂相比，NZBC 提取物使 120 分钟中等强度自行车运动期间的平均脂肪氧化增加了 27%（P=0.042），而平均碳水化合物氧化趋于降低（P=0.063）。新西兰黑加仑摄入后，静息状态下的血浆 NEFA（P=0.034）和甘油（P=0.051）浓度升高，尽管两种条件下运动引起的血浆 NEFA 和甘油浓度升高无差异（P>0.05）。运动期间的平均脂肪氧化与运动前的血浆 NEFA 浓度呈中度相关（r=0.45，P=0.016）。
NZBC 提取物摄入 7 天可提高静息状态下的血浆 NEFA 和甘油浓度，表明脂肪分解率更高，这可能是耐力训练女性在长时间自行车运动中脂肪氧化增加的原因。
