The Effect of Consuming 500 mL Low-Fat Milk on Cortisol Response and Salivary CRP After Resistance Training Among Young Healthy Women
Background: During acute severe muscular activities, the levels of inflammatory markers, including cortisol and C-reactive protein (CRP), significantly increase, which can be the underlying factor and the initiator of atherosclerosis and cardiovascular diseases. Given the complications and high prices of sports supplements consumed to neutralize these undesirable effects following acute severe muscular activities. Objectives: The purpose of this study was to evaluate the effect of consuming 500 mL of low-fat milk on cortisol and salivary CRP response after resistance training in young healthy women. Methods: In this study, two groups with the age range of 20 - 25 years and the body mass index (BMI) from 20 - 24.9 kg/m2 were recruited. Then, a group of 10 individuals performed two protocols at two intervals and were then compared together. The resistance training program included three sets with 10 reps and 75% intensity of a maximum rep in two one-hour sessions. On the first day, salivary sampling was carried out in fasting conditions, immediately before and after training, and also at the 60th and 120th minutes following it. One week later, in the second phase, the above-mentioned steps were fulfilled using 250 mL of low-fat milk in two sessions during sports activities. Descriptive statistics were also used to determine the mean and the standard deviation; and repeated measures analysis of variance (ANOVA) was employed at the inferential level. This test was employed to examine the main and the combined effects within four different times (immediately before and after training as well as one and two hours after training) in the experimental group in two different situations. The significance level of the tests was also considered as P < 0.05. Results: The results of the study did not reveal significant changes in the between-group comparisons of low-fat milk consumption in terms of cortisol and salivary CRP response after one-session resistance training program (P > 0.05). Conclusions: Based on the findings of this study, it was concluded that low-fat milk consumption was not able to adjust cortisol and CRP levels as inflammatory markers following one session of resistance training. Although milk consumption had reduced the CRP levels after training, this was not reported as a significant decrease. Definitely, measurement times in this test were of utmost importance.