Strength endurance training but not intensive strength training reduces senescence-prone T-cells in peripheral blood in community-dwelling elderly women.

Ageing is characterized by a progressive decline in immune function known as immunosenescence (IS). While the causes of IS are likely to be multi-factorial, an age-associated accumulation of senescent T-cells and decreased naïve T-cell repertoire are key contributors to the phenomenon. On the other hand, there is a growing consensus that physical exercise may improve immune response in ageing. However, the optimum training modality required to obtain beneficial adaptations in older subjects is lacking. Therefore, we aimed to investigate the effects of exercise modality on T-cell phenotypes in older women. 100 women (aged ≥65 years) were randomized to either intensive strength training (80% of one-repetition maximum (1RM)), strength endurance training (SET, 40% 1RM), or control (stretching exercise) for 2-3 times/week during 6 weeks. The T-cell percentages and absolute counts were determined using flow cytometry and hematology analyzer. C-reactive protein was measured using immunonephelometry. We report for the first time that 6 weeks of SET significantly decreased the basal percentage and absolute counts of senescence-prone T-cells, which was positively related to the number of training sessions performed. Conceivably, training protocols with many repetitions - at a sufficiently high external resistance - might assist the reduction of senescence-prone T-cells in older women.