Sample Size: 90 subjects will be recruited, following the first set of tests and experiments will randomly be divided into two matched groups experimental and experimental groups. The rational for sample size calculation is based on detecting a defined effect size with 5% statistical significance and 80% power. Effect size reflects the difference in the treatment effect between the groups will be calculated as the difference in measurement values between the experimental (probiotics) and control (placebo) groups divided by the standard deviation. Cyclists' cohort will include 34 subjects which will demonstrate effect size of 1.0. Masters runners' cohort will include 60 subjects which will demonstrate effect size of 0.75.