Single-Cell RNA Sequencing Analysis Reveals Exercise-Induced Transcriptional Dynamics in Half-Marathon Runners

Previous studies in sports science suggested that regular exercise has a positive impact on human health. However, the effects of endurance sports and their underlying mechanisms are still not completely understood. One of the main debates regards the modulation of immune dynamics in high-intensity exercise. As part of the "Run 4 Science" project in Verona, Italy, we conducted a single-cell RNA sequencing analysis on half-marathon amateur runners to investigate the transcriptional dynamics of peripheral blood mononuclear cells following endurance exercise. Blood samples were collected from four participants before and after running a half-marathon to carry out a comprehensive transcriptomic analysis of immune cells at the single-cell level. Our analysis revealed significant alterations in the transcriptional profiles following endurance physical exercise. Modulations in myeloid cells suggested the activation of stress response (6 related pathways, p < 0.04) and pathways related to viral processes (4 related pathways, p < 0.03), while in lymphoid cells they hinted to a shift towards immune activation (24 related pathways, p < 0.01). Additionally, transcriptional changes in platelets point to an activation of the coagulation process (5 related pathways, p < 0.005). Single-cell data was also analyzed following a pseudo-bulk approach (i.e., simulating a bulk RNAseq experiment) to gain further biological insights. Our findings suggest that a pseudo-bulk analysis could offer complementary findings to classical single-cell analysis methods and demonstrate that endurance physical exercise, such as running a half-marathon, induces substantial changes in the transcriptional dynamics of immune cells. These insights contribute to a better understanding of the immune modulation mediated by endurance exercise and may inform future training routines or nutritional guidelines based on individual gene expression levels.