Fermented Whey Protein Supplementation Improves Muscular Strength, Muscle Parameters, and Physical Performance in Middle-Aged Korean Adults: An 8-Week Double Blind Randomized Controlled Trial
Cheol‐Hyun Kim, Yu-Bin Jeon, Dong-Gyu Yoo, Ki-Hong Kim, Hwan-Jong Jeong, Byung-Kwan Kim, Mi-Houn Park, Ki-Hwan Kim, Joon‐Ho Hwang, Gun Hee Cho, Sung‐Kyu Kim, Ki-Woong Lee, Sung-Han Kim
Abstract
This study aimed to evaluate the effects of fermented whey protein using kimchi lactic acid bacteria Lactobacillus casei DK211 on skeletal muscle mass, muscular strength, and physical performance in healthy middle-aged males undergoing regular resistance exercise. To improve muscular health, effective protein supplementation and regular exercise are two important factors. Therefore, the effects of consuming fermented whey protein twice a day were investigated here in comparison with non-fermented supplementation. Forty-eight males with an average age of 44.8 were randomly assigned to two groups: Fermented whey (FWPS, Fermented whey protein supplementation) and non-fermented (WPCS, Whey protein concentration supplementation) groups. Each group ingested 37g of FWPS or WPCS consumed twice a day for eight weeks. Body composition, muscular strength, and physical performance were all assessed pre- and post-intervention. Independent T tests or chi-square tests for the categorical variables were subsequently performed for analysis of the results. Fermented whey protein supplementation was found to be effective in promoting the physical performance of dynamic balance measurement, and muscle health, as indicated through increment of grip strength (left), upper arm circumference, and flat leg circumference from the baseline. However, similar improvements were not observed in the non-fermented group. These results suggested that fermentation of whey protein by Lactobacillus casei DK211 exhibited an effective protein supplement for enhancing muscular health in male subjects undergoing regular resistance exercise.