Sarcomere Disruptions of Slow Fiber Resulting From Mountain Ultramarathon

Abstract

Since there is evidence of muscle damage after prolonged mountain running, the increase in SM serum concentration after a MUM could be indirect evidence of slow- (type I) fiber-specific sarcomere disruptions.

Fibre-type-specific and Mitochondrial Biomarkers of Muscle Damage after Mountain Races

“…The release of sarcomere proteins, such as myosin, from muscle fibres to the bloodstream has been reported previously as indirect evidence of sarcomere damage [7,9]. In the present study, only the 55 km MTR induced an increase in SM in serum that suggests the presence of slow (type I) fibre sarcomere damage.…”

“…To overcome these limitations, other biomarkers related with a different cellular structure have been used in order to characterize the exercise impact on muscle fibres. Serum levels of fast and slow myosin (FM and SM, respectively) isoforms have been used as indirect biomarkers of fibretype-specific sarcomere damage [7,9], and sarcomeric mitochondrial CK (sMtCK) to evaluate mitochondrial integrity [8]. Specifically , significant increases in SM, suggesting sarcomere disruption in slow (type I) fibres, were found in 85 km MTR participants who completed different overall distances during the whole race [9].…”

“…Serum levels of fast and slow myosin (FM and SM, respectively) isoforms have been used as indirect biomarkers of fibretype-specific sarcomere damage [7,9], and sarcomeric mitochondrial CK (sMtCK) to evaluate mitochondrial integrity [8]. Specifically , significant increases in SM, suggesting sarcomere disruption in slow (type I) fibres, were found in 85 km MTR participants who completed different overall distances during the whole race [9]. Moreover, increases in serum sMtCK could be indicative of the number of myofibrils that have died by either apoptosis (due to a process triggered by large increases in sMtCK) and/or necrosis [8].…”

Comparison of vitality states of finishers and withdrawers in trail running: An enactive and phenomenological perspective

“…In this case, studies are based on the assumption that performance is dependent on two types of factors: (a) before-the-race factors, which include, for example, training habits [6], the impact of training characteristics on running-related injuries [7], and physical, mental and tactical preparation [4], and (b) during-the-race factors, which include sleep-deprivation effects [8] and neuromuscular damage [9]. Other determinants of performance have been examined by isolating specific characteristics, without distinguishing between these two types of timed factors; these include mood states [10], cognitive functioning [11], personality traits [12], emotions [13], sarcomere disruption [14], and alteration of jump height mechanics after a mountain footrace [15]. However, these approaches partition the unity of runners’ activity into specific processes, which precludes the possibility of understanding runners from a holistic perspective ‒ that is, as capable of compensating a performance deficit in one phase of the race by heightened performance in another phase, or compensating one process by another, such as psychological coping with physiological problems [16].…”

Significant effusion in the joints of the lower extremity after running an ultramarathon in extreme conditions

“…The continuous muscular exertion during the run results in elevation of creatine kinase (CK) and there is evidence of type Ifibre sarcomere disruptions throughout mountain ultramarathons. (Magrini, Khodaee, San-Millán, Hew-Butler, & Provance, 2017) , (Carmona et al, 2015) Previously, researchers examined the Swiss Alpine Marathon (Davos, 67 km) and reported muscle soreness and elevated levels of C-reactive protein (CRP) and CK after the run. (Frey et al, 1994) Surprisingly, anthropometric data and data on lower extremities is scarce for ultramarathons, although these are frequently studied topics in other running disciplines especially in classic marathons.…”