Acute Inflammatory Responses To Three Different Isokinetic Bench Press Loading Protocols

Abstract

Introduction: Exercise disturbs the homeostasis in the body and induces a transient inflammatory response leading to an acute increase in acute phase proteins, cytokines and enzymes, which can be classified as an acute inflammatory response to exercising. The purpose of this study was to evaluate the effects of an isokinetic bench press protocols consisting of eccentric-only (ECC), concentric-only (CON) and combined (COMB) concentric-eccentric muscle actions on the acute inflammatory markers interleukin-6 (IL-6), C-reactive protein (CRP) and muscle damage marker creatine-kinase (CK).

Methods: Twelve healthy resistance-trained males completed the study. Subjects completed three different maximal isokinetic loadings: CON, ECC and COMB with each consisting of 5 sets of 10 maximal repetitions separated by 14 days in a randomized order. Maximal isometric force (ISOM) was measured before, immediately after (post-45s) and 24-hours after the protocol (post-24h). IL-6, CRP, CK and Blood lactate (LAC) was measured before (pre), 5-minutes (post-5min) and 24-hours after each protocol.

Results: ISOM force decreased significantly at post-45s and remained significantly decreased at post-24h after all protocols. No significant increases were found in IL-6 at any measured time-point. A significant increase was found in CRP at post-5min after the ECC protocol. No significant increases were found in CRP at any other time-point or protocol. CK increased significantly at post-5min in all protocols but no significant differences were found at any other time-point or protocol. A significant increase was found in blood lactate after all protocols at post-5min and a significant difference at post-5min between the ECC and COMB protocols.

Conclusions: Five sets of ten repetitions of maximal isokinetic bench press was sufficient to decrease maximal isometric force production to a moderate degree. However, no increases of acute inflammatory markers or markers of muscle damage was present 24 hours after the completion of the protocols, despite the difference in force loss at the post-45s between protocols and the lower metabolic cost of the ECC protocol.