2.4. Whey Protein Supplement and Placebo
The whey protein supplement and placebo contained the same calorie content of 99 kcal per pack and were administered to the PSG and CON respectively. The whey protein supplement and placebo were formulated in powder form by Maeil Health Nutrition Co. Ltd. (Gyeonggi-do, Republic of Korea). One pack of whey protein powder supplement contained 20 g of whey protein isolate, 8 g of carbohydrate, and 6.4 g of dietary fiber, and one pack of placebo contained 25 g of carbohydrate instead of protein. Each participant consumed either a whey protein supplement or a placebo 3 times a day: morning, post-exercise, and evening. All powders were flavored with chocolate to mask their contents and were provided in unlabeled packaging to ensure that the study participants or researchers could not tell them apart.