Interval and Continuous Exercise Regimens Reduce Senescent T‐Lymphocyte Subsets in Blood

Abstract

The integration and control of systemic immune responses depends on the regulated trafficking of T‐lymphocytes. This study elucidates how interval and continuous exercise regimens affect phenotypic characteristics of T‐lymphocyte subsets in blood. Twenty‐four sedentary males were randomized to perform either aerobic interval training (AIT; 3‐minute intervals at 40% and 80%VO2max, n=12) or moderate continuous training (MCT; sustained 60%VO2max, n=12) for 30 minutes/day, 5 days/week for 6 weeks. At rest and immediately after hypoxic exercise test (HE, 100W under 12%O2 for 30 min), the senescent (CD57), co‐stimulatory (CD28), homing (CD11a and CD62L), and naïve/memory (CD47Ra/CD47Ro) molecules on T‐lymphocyte subsets were measured by flow cytometry. The results showed that HE increased the mobilization of CD4, CD8, or CD8bright lymphocytes expressing CD11a or CD57 molecules into the peripheral blood compartment before performing AIT or MCT. Following the 6‐week intervention, both MCT and AIT up‐regulated CD28, CD11a, and CD45Ra molecules and depressed CD57 expression on CD4, CD8, or CD8bright lymphocytes at rest or following HE. Therefore, we conclude thateither AIT or MCT regimen effectively reduce senescent and enrich homing and co‐stimulatory T‐lymphocyte subsets in blood. These findings can help to determine an effective exercise regimen to minimize immune dysfunction by retarding T‐lymphocyte senescence.