Background: Pre-workout multi-ingredients are designed to enhance energy levels and acutely increase exercise performance. This study compared the effectiveness of ingesting an admixture providing caffeinated ingredients and plant-based protein enriched with amino acids versus carbohydrates alone on body composition, hypertrophy and physical performance.

Methods: Forty-three middle-aged physically active individuals (26 peri- and post-menopausal females and 17 males) completed the study after being randomly assigned to one of the following intervention groups: pre-workout (PREW n = 24, 54 ± 4 years, body mass 77.6 ± 16.0 kg) or a carbohydrate-only comparator (COMP n = 19, 52 ± 4 years, body mass 80.6 ± 16.0 kg). Measurement of fat and fat-free mass (via plethysmography), waist and hip circumferences, muscle thickness (via ultrasound), strength, power output and muscle endurance performance were collected before and after a 6-week resistance training programme performed 3 times per week. Treatment consisted of ingesting 30g of the assigned supplement, mixed with 400mL of plain water, 15min before each workout session.

Results: Both groups significantly (p < 0.05) reduced fat mass (mean ± SD) (PREW -1.4 ± 1.6 kg; COMP -1.0 ± 1.5 kg), increased fat-free mass (PREW +0.9 ± 1.1 kg; COMP + 0.8 ± 0.9 kg); vastus lateralis (PREW +0.2 ± 0.2 cm; COMP + 0.1 ± 0.6 cm), and elbow flexors (PREW +0.5 ± 0.3 cm; COMP + 0.4 ± 0.2 cm) muscle thickness. Only the PREW group showed a significant reduction in the waist circumference (-1.8 ± 1.8 cm, p < 0.01). However, no significant differences between groups (PREW vs. COMP) were identified at post-intervention. Isometric force, countermovement jump, medicine ball throw, and upper and lower body muscle endurance performance improved (p < 0.05) for both treatments, with no difference between groups.

Conclusion: Except for waist circumference reduction, ingesting a pre-workout vegan protein-based caffeinated supplement promotes no further resistance training benefits in middle-aged individuals.

Keywords: Multi-Nutrient; Nutrition; caffeine; fat mass; fat-free mass; supplementation.

背景：

运动前多成分补充剂旨在提升能量水平，并在短期内提高锻炼表现。本研究比较了摄入提供含咖啡因成分和富含氨基酸的植物蛋白混合物与单纯碳水化合物对身体组成、肌肉增长及体能表现的效果。

方法：

43名中年活跃人士（包括26名围绝经期和绝经后女性以及17名男性）被随机分配到以下干预组之一：运动前补充剂组（PREW，n=24，平均年龄54±4岁，体重77.6±16.0kg）或单纯碳水化合物对照组（COMP，n=19，平均年龄52±4岁，体重80.6±16.0kg）。在为期六周、每周三次的抗阻训练计划前后测量体脂和去脂体重（通过容积法）、腰围和臀围、肌肉厚度（通过超声波）以及力量、功率输出及肌耐力表现。治疗包括在每次锻炼前15分钟摄入30克指定补充剂，混合400毫升纯净水。

结果：

两组均显著减少了体脂（PREW减少1.4±1.6kg；COMP减少1.0±1.5kg），增加了去脂体重（PREW增加0.9±1.1kg；COMP增加0.8±0.9kg）；股直肌厚度（PREW增加0.2±0.2cm；COMP增加0.1±0.6cm）和屈肘肌肉厚度（PREW增加0.5±0.3cm；COMP增加0.4±0.2cm）。然而，只有运动前补充剂组显著减少了腰围（减少1.8±1.8cm，p

结论：

除了减少腰围外，摄入一种基于植物蛋白的含咖啡因运动前补充剂对中年人群的抗阻训练没有进一步的好处。

关键词：

多营养素；营养；咖啡因；体脂；去脂体重；补充剂。