Eccentric and concentric resistance exercise induced changes on insulin sensitivity and inflammation

Abstract

Purpose: The aim of this study was to compare the effects of an acute bout of eccentriconly (ECC) resistance exercise to an acute bout of concentric-only (CON) resistance exercise on glucose tolerance and to investigate the role of inflammation in any observed differences. Methods: Fourteen overweight, untrained participants (BMI = 33.6 ± 1.2) performed either an ECC (N = 7) or CON (N = 7) resistance exercise session. An oral glucose tolerance test was administered days before and 24-hours post-exercise. The exercise session consisted of 1-repetition maximum (1RM) testing followed by three sets of ten repetitions at 75% of their contraction specific 1RM on a knee extension machine and leg curl machine. Blood samples were analyzed for IL-6 and TNFa and delayed onset muscle soreness (DOMS) was measured. Results: ANOVA calculations indicated a trend on glucose tolerance between the groups' pre- and post-exercise sessions (p = 0.098). There was also a trend observed in IL-6 between the 1h and 24h measurements (p = 0.097), but no differences between the groups. No changes in TNFa were observed. ECC exercise increased soreness that peaked at 48h and CON exercise induced no soreness changes. Conclusions: These data suggest that in an overweight, untrained population, an acute bout of ECC-only or CON-only resistance exercise may cause opposite effects on glucose tolerance; ECC exercise decreasing glucose tolerance, CON exercise increasing glucose tolerance. Opposing effects on glucose tolerance from the exercise occurred in lieu of a similar response in IL-6 and TNFa to the exercise.