Eccentric cycling exercise (ECE) features lower metabolic demand and higher improvement of muscle strength compared to traditional concentric cycling exercise (CCE). Mitochondria can regulate energy metabolism and adaptive immune quality in T lymphocytes. However, the effects of ECE on mitochondrial functions in T-lymphocytes have not yet been established.

Method: A total of 33 healthy sedentary males were randomized and divided into ECE (n=11), CCE (n=11), and control groups (n=11). These subjects progressively performed CCE or ECE from 60% to 80% maximal workload on a bicycle ergometer for 40 min/day, 5 days/week for 6 weeks. A graded exercise testing and an isokinetic strength test were conducted to evaluate cardiopulmonary fitness and muscle strength, respectively. Phenotypes and mitochondrial respiratory capacity in T lymphocyte were analyzed using flow cytometry and high-resolution respirometer, respectively.

Eccentric exercise training (EET) increases physical performance while having lower metabolic demand than concentric exercise training (CET).

Mitochondria of lymphocytes are essential for cell proliferation, death, and differentiation, and play a critical role in establishing lymphocyte phenotypes and their functions.

Whether EET influences lymphocyte bioenergetic efficiency remains unclear. The study was to investigate the effects of ECE and CCE regimens on adaptive immune functions and mitochondrial bioenergetics of T lymphocytes in sedentary males.

Inclusion Criteria:

1. Sedentary lifestyle.
2. Nonsmokers, nonusers of medications/vitamins.
3. No any cardiopulmonary/hematological risks.

Exclusion Criteria:

1. Have regular exercise habits (i.e., exercise frequency once per week, duration >20 min).
2. Have retabolic or musculoskeletal disease.