Complement Proteins (C1est, C4, C6), Circulating Immune Complexes and the Repeated Bout Effect

Abstract

Purpose. To determine if the complement system is activated following strenuous eccentrically-biased exercise. Secondly, to determine if com plement activation is attenuated (repeated bout effect) following a second bout of the same exercise. Basic procedures. Healthy, active but untrained males performed 2 × 60 min bouts of downhill running, 14 days apart. Samples were taken pre, immediately post (IP), then every hour for twelve hours, and at 24, 48, 72, 96, 120 and 144 h post exercise. concentrations of c1est, c4, and circulating immune complexes (cIc's) were determined using standardised nephelometery. c6 was determined using radial immunodifusion. The variables were analysed using a repeated measures ANOVA, with significance set at p < 0.05. Main findings. A significant ( p < 0.01) run effect was observed for c1est, c4, c6 and cIc's with the concentrations elevated after run 2 compared with run 1. c1est and c4 exhibited significant time effects ( p < 0.001). Conclusions. The complement system is activated following a strenuous bout of downhill running. complement proteins and circulating immune com plexes do not exhibit the same traditional 'repeated bout effect' as many other common markers of muscle damage/inflammation. The increase in complement proteins following the second bout may indicate enhanced innate immune function and/or an amplification of the immune response to tissue damage through interaction with the adaptive immune system.

The Repeated Bout Effect of Multiarticular Exercises on Muscle Damage Markers and Physical Performances: A Systematic Review and Meta-Analyses

“…For studies that incorporated running activities to cause EIMD, the majority consisted of downhill running protocol on a motorized treadmill (9,10,26,28,38,(44)(45)(46)(48)(49)(50)(51)53,54), with 2 studies that included level ground running (40,56) (Table 1). The downhill running protocol was either conducted as continuous running for 12-60 minutes at 210% to 220% gradient or intermittent running of 5 to 9 sets of 5-8 minutes of running at 28.5% to 212% gradient.…”

“…The characteristics of subjects from each study are presented in Table 1, with a total of 244 subjects (males 5 203; females 5 41). The descriptions regarding exercise backgrounds varied between physically active individuals (26,(44)(45)(46)50,51,53,54), recreationally active in sports or endurance exercise (7,8), recreational athletes (28), recreational runners (23,24,38), moderately trained (48) and well-trained team sports players (40), and collegiate athletes (56), whereas some studies did not provide information regarding exercise backgrounds (3,9,49). Most studies reported age, height, and body mass, with mean 6 SD values of 22.2 6 2.9 years, 75.2 6 6.6 kg, and 177.1 6 5.7 cm, respectively.…”

“…Most studies reported age, height, and body mass, with mean 6 SD values of 22.2 6 2.9 years, 75.2 6 6.6 kg, and 177.1 6 5.7 cm, respectively. Only about half the number of studies (3,7,8,23,24,40,(44)(45)(46)48,51,53,54) reported maximal oxygen uptake, with an average of 50.2 6 3.2 ml•kg 21 •min 21 .…”

“…However, there are also studies that have reported no differences in muscle performance measures (26,40,49), running economy (24), and running time-to-exhaustion (23) between 2 bouts of multiarticular muscle-damaging exercises. In addition, for studies that reported lower levels of CK and DOMS after the second bout of running activities (3,9,26,28,44–46,49–51,54,56), the magnitude of changes varied substantially between studies, making overall interpretations difficult. Collectively, the magnitude of the RBE trend seems to be influenced by several methodological factors.…”

Acute protease supplementation effects on muscle damage and recovery across consecutive days of cycle racing

“…Consecutive days of high-intensity exercise, as experienced by endurance cyclists during competitive cycle tours, have been associated with an acute pro-inflammatory response (Semple et al, 2006). Markers of muscle damage such as creatine kinase (CK) and lactate dehydrogenase (LDH; Chan, Heist, DePaoli, Veldhuis, & Mantzoros, 2003) have previously been reported to be elevated following endurance cycling (Greer, Woodard, White, Arguello, & Haymes, 2007) and this damage has been associated with a reduction in power output (Greer et al, 2007), affecting cycling performance.…”