Author(s): PENG, S.C., LU, T.Y., LO, K.M., WANG, J.S., Institution: CHANG GUNG UNIVERSITY, Country: TAIWAN, Abstract-ID: 437

INTRODUCTION:
Eccentric cycling training improves exercise performance via lower metabolic demand. Assistive devices like neuromuscular electrical stimulation (NMES) and compressive garments (CG) are reported to attenuate muscle damage following high-intensity eccentric exercise. Mitochondria in T lymphocytes dominate acquired immunity and metabolism. The current understanding of eccentric cycling exercise combined with assistive devices on mitochondrial functions in T-lymphocytes remains unclear. This study attempted to evaluate the effects of eccentric cycling exercise training combined with assistive devices on phenotypes and mitochondrial metabolism of T lymphocytes.
METHODS:
Twenty sedentary healthy males were randomly assigned to either eccentric cycling with assistive devices (ECA, n=10) or eccentric cycling only (ECC, n=10). Cardiopulmonary exercise testing (CPET) was conducted to determine aerobic fitness. All subjects performed ECA or ECC at an intensity of 60% to 120% maximal workload progressively on a bicycle ergometer for 40 min/day, 5 days/week for 5 weeks. A high-resolution respirometer and flow cytometer were used for analyzing mitochondrial metabolism and phenotypes in T lymphocytes. Statistics were presented using two-way repeated measures ANOVA with Bonferroni post-hoc test.
RESULTS:
The ECA (176 ± 7 vs. 190 ± 8 watts, p<0.05) and the ECC (174 ± 2 vs. 192 ± 7 watts, p<0.05) both increased work rates of CPET after training for 5 weeks. The ECA decreased the pain visual analogue scale on the first week of exercise training (ECA:2.0 ± 0.5 vs. ECC:4.0 ± 0.2, p<0.05), compared to the ECC. An elevation of the percentage of central memory T cells (CD45RO+62L+) was observed in the ECC (20.9 ± 0.9 vs. 26.3 ± 2.4 %). Moreover, the intervention enhanced mitochondrial fatty acid oxidation (FAO) of lymphocytes in both ECA (29.0 ± 2.7 vs. 37.7 ± 2.9 pmol/s/106 cells, p=0.044) and the ECC (28.4 ± 3.3 vs. 38.3 ± 2.5 pmol/s/106 cells, p=0.039), the latter also increased respiration of Complex II of electron transport chain (ETC) (17.8 ± 2.2 vs. 23.7 ± 1.6 pmol/s/106 cells, p=0.023).
CONCLUSION:
The ECA predominately alleviates perceived muscle soreness during exercise training. In addition, both ECA and ECC increase mitochondrial FAO capacity, whereas only the ECC enhances ETC Complex II metabolism, and there is no significant difference between the two regimens.