SOY PROTEIN BAR INGESTION DOES NOT IMPROVE RUNNING PERFORMANCE
Huang, Z.-M., Hsu, S.-Y., Wen, Z. K., Chang, W.-H. (2014). Anti-fatigue effects of long-term supplementation with soy protein bar in college sports teams. Medicine & Science in Sports & Exercise, 46(5), Supplement abstract number 380.
The study determined the effects of long-term consumption of soy protein bars on lean mass and markers of fatigue in college sports team students (N = 60). Ss participated in a randomized crossover-design study. Each S consumed three soy protein bars per day or maintained their previous dietary habits (Control group) for seven days with a one-week washout period. The fatigue-inducing physical test consisted of a continuous run at a speed corresponding to 70% maximum heart rate for 30 minutes, and then the running speed was increased by 1 km/hour every minute until exhaustion. Fatigue markers were evaluated two ways: i) physical performance [running time and rating of perceived exertion score]; and ii) key blood biochemical parameters [blood glucose, lactate, ammonia, and creatine phosphokinase levels]. Blood samples were taken before, during, and at exhaustion, 30, 60, and 90 minutes after exercise.
Compared to the control group, soy protein bar consumption showed a significant increase in muscle mass and significant decrease in serum creatine phosphokinase and ammonia concentrations. The pattern of change between the two groups was significant for blood glucose with the soy protein bar intervention sustaining higher levels. There were no significant differences for running time, rating of perceived exertion, and serum lactate levels.
Implication. Consumption of soy protein bar for seven days could promote gains in lean body mass and improve glucose and lactate metabolism after exercise but does not improve performance.
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