The probiotics can be useful to improve the immune response in experimental challenges, like the exhausting exercise, that cause immunosuppression. We have evaluated a probiotic yogurt and a probiotic whey beverage using an exhausting physical-exercise protocol with rats. Wistar rats were given a daily 4-mL supplement of each type of conventional or probiotic yogurt and whey beverage, manufactured with lactic culture Streptococcus thermophilus TA040 and Lactobacillus bulgaricus LB340, and probiotic culture Lactobacillus acidophilus LA 14 and Bifidobacterium longum BL 05. The effects on the immune system were compared to those of pair-treated cohorts receiving for 14 days. Results demonstrated that the probiotic yogurt outperformed the probiotic whey beverage in blood-cell indicators (neutrophils and lymphocytes), cytokines (TNF-alpha and IL-1 beta) and various standard health parameters. In conclusion, in this study, the treadmill exercise assay successfully produced immunosuppression in the rat and the combination of the nutrients and probiotic bacteria of the yogurt reduces more effectively the adverse effects developed over the prolonged strenuous exercise than did a similar probiotic whey beverage. (C) 2013 Elsevier Ltd. All rights reserved.541118124