Background: Different exercise intensity has a various effect on the immune system. Lactate is one of the factors that releases in exercise, on one hand, higher lactate concentration not also apoptosis of peripheral blood mononuclear cells (PBMCs) decrease but also the survival of the PBMCs increase (Elsaser et al., 2017), on the other hand, lactate enhance proinflammatory cytokines in the lymphocytes (Pedersen, 2000). 

Methods: In this study, ten sedentary young women aged 22 to 29 years performed walking or running on the treadmill at either 60 percent and 90 percent of maximal heart rate (HRmax). After two weeks, subjects switched crossover their groups and began working with other intensity, 60 or 90 percent, that they did not do the last two weeks. Blood samples were taken before and five minutes after the test for measuring lactate level, apoptosis, necrosis, and survival of peripheral blood mononuclear cells (PBMCs). 

Results: The main effect of the two different types of the intensity of the exercise on the lactate was statistically significant (p< 0.001). Moreover, the main effect of the two different types of the intensity of the exercise on apoptosis and survival of the PBMCs were statistically significant (p< 0.031 and p< 0.038, respectively). 

In conclusion, Increase the level of the amount of lactate during the exercise with 90 HRmax may influence the immune system through enhance survival and decrease the apoptosis of the PBMCs.