Department of Human Movement Sciences, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Centre, Maastricht, The Netherlands.
Med Sci Sports Exerc. 2012 Apr;44(4):692-700. doi: 10.1249/MSS.0b013e31823a40ef.
Both protein and caffeine coingestion with CHO have been suggested to represent effective dietary strategies to further accelerate postexercise muscle glycogen synthesis in athletes.
This study aimed to assess the effect of protein or caffeine coingestion on postexercise muscle glycogen synthesis rates when optimal amounts of CHO are ingested.
Fourteen male cyclists were studied on three different test days. Each test day started with a glycogen-depleting exercise session. This was followed by a 6-h recovery period, during which subjects received 1.2 g·kg⁻¹·h⁻¹ CHO, the same amount of CHO with 0.3 g·kg⁻¹·h⁻¹ of a protein plus leucine mixture (CHO + PRO), or 1.7 mg·kg⁻¹·h⁻¹ caffeine (CHO + CAF). All drinks were enriched with [U-¹³C₆]-labeled glucose to assess potential differences in the appearance rate of ingested glucose from the gut. Muscle biopsies were collected immediately after cessation of exercise and after 6 h of postexercise recovery.
The plasma insulin response was higher in CHO + PRO compared with CHO and CHO + CAF (P < 0.01). Plasma glucose responses and glucose appearance rates did not differ between experiments. Muscle glycogen synthesis rates averaged 31 ± 4, 34 ± 4, and 31 ± 4 mmol·kg⁻¹ dry weight·h⁻¹ in CHO, CHO + PRO, and CHO + CAF, respectively (P = NS). In accordance, histochemical analyses did not show any differences between net changes in Type I and Type II muscle fiber glycogen content between experiments.
Coingestion of protein or caffeine does not further accelerate postexercise muscle glycogen synthesis when ample amounts of CHO (1.2 g·kg⁻¹·h⁻¹) are ingested.
有研究表明，在摄入碳水化合物（CHO）的同时摄入蛋白质和咖啡因，可以作为有效的饮食策略，进一步加速运动员运动后的肌肉糖原合成。
本研究旨在评估在摄入最佳量的 CHO 时，蛋白质或咖啡因共摄入对运动后肌肉糖原合成率的影响。
14 名男性自行车运动员在 3 个不同的测试日进行了研究。每个测试日均以耗竭糖原的运动训练开始。随后进行 6 小时恢复期，期间受试者摄入 1.2 g·kg⁻¹·h⁻¹ CHO，或相同量的 CHO 与 0.3 g·kg⁻¹·h⁻¹的蛋白质加亮氨酸混合物（CHO + PRO），或 1.7 mg·kg⁻¹·h⁻¹咖啡因（CHO + CAF）。所有饮料均用 [U-¹³C₆]-标记的葡萄糖进行强化，以评估肠道中摄入葡萄糖的出现率的潜在差异。运动结束后立即采集肌肉活检，并在运动后 6 小时进行采集。
CHO + PRO 组的血浆胰岛素反应高于 CHO 和 CHO + CAF 组（P < 0.01）。实验之间的血浆葡萄糖反应和葡萄糖出现率没有差异。CHO、CHO + PRO 和 CHO + CAF 组的肌肉糖原合成率分别为 31 ± 4、34 ± 4 和 31 ± 4 mmol·kg⁻¹干重·h⁻¹（P = NS）。相应地，组织化学分析显示实验之间 Type I 和 Type II 肌纤维糖原含量的净变化之间没有差异。
当摄入足够量的 CHO（1.2 g·kg⁻¹·h⁻¹）时，共摄入蛋白质或咖啡因并不能进一步加速运动后的肌肉糖原合成。
