乳清蛋白為優質的蛋白質來源，可從乳清中分離出來，含有大量的必需胺基酸，尤其是支鏈胺基酸（白胺酸、異白胺酸、纈氨酸）。乳清蛋白已被證實具有刺激肌肉蛋白合成、減少肌肉損傷以及增加運動表現之效果，故為世界知名運動營養補充品之一。過去研究報告亦顯示，乳清蛋白具有多樣生物活性，包括：抗發炎、抗氧化、預防骨質疏鬆以及降低心血管疾病危險因子，並且具有調節血糖以及改善肥胖與第二型糖尿病之效果。儘管過去許多研究已指出補充乳清蛋白對於體能與肌力訓練具有提升肌肉量與促進運動表現的好處。然而有氧運動訓練合併使用乳清蛋白的生物作用與功效，則是較少有研究成果報導。我們實驗室最近的實驗數據證實，乳清蛋白對於密集有氧運動訓練具有顯著提升運動表現表現與降低體重之效果。因此，希望透過本文獻回顧，能夠讓從事現場訓練工作的教練、運動訓練員、專業體能指導員或運動選手以及熱愛運動健身的對象，瞭解知名運動營養補充品─乳清蛋白的特性與最新研究報告。並期望能夠對於推動我國競技運動發展及奧亞運動項目之重要實務應用有所助益。

Whey protein (WP) is derived from milk and rich in high quality protein. WP contains all essential amino acids, particularly branched-chain amino acids (i.e., leucine, isoleucine and valine). WP is one of the world’s wellknown sports nutrition supplements, it has been demonstrated to stimulate muscle protein synthesis, reduce muscle damage and improve exercise performance. Many reports have indicated that WP possesses a wide spectrum of activities in biological systems including anti-inflammation, anti-oxidation, osteoporosis prevention, reduction of cardiovascular risk factors, glycemic control, and treatment of obesity and Type 2 diabetes. While the benefit of WP supplementation during strength training and conditioning is becoming increasingly well-documented, little is known with respect to WP supplementation and long-term aerobic exercise training. Recent report also demonstrated that WP supplementation improved exercise performance, body composition and clinical biochemistry, and may be an effective ergogenic aid in aerobic exercise training. The aim of this literature review is to introduce the nutritional characteristics and novel biological functions of WP for coaches, athletic trainers, strength and conditioning specialists, athletes and exercise enthusiasts. We also expected this review article could contribute to the promotion and development of our practical applications and athletic achievements in the Olympic and Asian games.