Intensity-dependent stimulation of leukocyte telomerase activity by endurance exercise – a pilot study

Abstract Objectives Exercise induces telomerase activity and regulates shelterin expression. These effects are believed to preserve telomeres. However, the impact of exercise intensity on telomerase and shelterins has not been studied systematically. This pilot study investigated the kinetics of leukocyte telomerase activity (LTA) and the expression of telomere-related genes in response to exercise at different intensities. Methods Seven healthy women completed three exercise sessions at low, moderate and high intensity on a stationary bicycle ergometer. Blood was collected before, 24 and 48 h after each session. LTA, leukocyte telomere length (LTL), expression of telomerase reverse transcriptase (TERT), telomeric repeat binding factor 1 (TERF-1), 2 (TERF-2) and the serum concentration of telomeric repeat binding factor-1 protein (TRF-1) were determined. Results LTA increased 24 h after moderate and high intensity exercise and returned to baseline levels after 48 h. TERF-2 expression showed a tendency to decrease 24 h after high-intensity exercise. Other markers (TERT, TERF-1, LTL, TRF-1) were not affected by any intensity. Conclusions From the present results it can be concluded that the telomeric effects of exercise are short-lived and depend on the intensity level. Future studies should confirm these results in a larger cohort focusing on the first 24 h post-exercise.