Biomarcadors sanguinis per a la caracterització del dany muscular induït per exercicis del tren inferior = Blood biomarkers for the characterization of muscle damage induced by lower limb exercises

[cat] L'objectiu d'aquesta tesi ha estat caracteritzar el dany muscular induït per diversos exercicis del tren inferior mitjançant l'anàlisi de l'evolució temporal i la magnitud de canvi de l'activitat o la concentració de marcadors bioquímics sèrics. Amb aquesta finalitat, el dany muscular induït per diversos exercicis del tren inferior s’ha avaluat mitjançant protocols de laboratori basats en exercicis d'alta intensitat (HIE) (estudis I, II i III) i protocols de camp consistents en exercicis de llarga durada (LDE) (estudis IV i V). Exercici d'alta intensitat En el primer estudi (I), el dany muscular induït per un exercici de mig esquat inercial d’alta intensitat es va avaluar mitjançant l'evolució en sèrum de l’activitat d'enzims musculars i la concentració de proteïnes del sarcòmer específiques del tipus de fibra (ràpida [tipus II] o lenta [tipus I]), com ara les isoformes ràpida (tipus II) i lenta (tipus I o ß) de la miosina (FM i SM, respectivament). Es van registrar els perfils sèrics de deu homes joves, sans i físicament actius a l'inici de l'estudi i en diversos punts temporals després de l'exercici. Mentre que l'augment sèric d’enzims musculars va suggerir un increment de la permeabilitat de la membrana tant de les fibres lentes (tipus I) com de les ràpides (tipus II), l’increment d’FM va suggerir la disrupció del sarcòmer, i també un increment de la permeabilitat de la membrana de fibres ràpides (tipus II). Per tant, vam concloure que un model molecular indirecte de dany muscular induït es pot construir mitjançant l’avaluació de l'evolució temporal de l'activitat o la concentració sèrica d'enzims i proteïnes musculars, d'acord amb el seu pes molecular, el compartiment de la fibra en la qual es troben i el tipus de fibra (ràpida [tipus II] o lenta [tipus I]) en les quals s'expressen. Durant el segon estudi (II) es va aplicar el model molecular indirecte d’EIMD per avaluar la resposta muscular. Concretament, es va avaluar, en un saltador de perxa entrenat (PV) i un estudiant d'educació física (PE), l'efecte d'un exercici de premsa de cames fins a l’extenuació (LPF). Els paràmetres mecànics de l’exercici es van utilitzar com a indicadors del rendiment i la fatiga induïda per LPF. El PV va revelar un perfil explosiu (orientat a la potència) que va induir a danys lleus i selectius de les fibres ràpides (tipus II). Per contra, el PE va mostrar un perfil resistent a la fatiga, i també una activitat enzimàtica superior i una elevada concentració sèrica d’SM, cosa que suggereix un grau més alt de dany de les fibres lentes (tipus I). En l'últim estudi d’HIE (III), es va investigar el grau de dany induït per un exercici excèntric intensiu sobre la musculatura isquiotibial i es van analitzar les diferències en el grau de dany intersubjectes i intrasubjectes (comparació entre extremitats d’un mateix subjecte). Amb aquesta finalitat, es va avaluar la relació entre biomarcadors sèrics i altres marcadors indirectes de dany muscular. Tretze homes van realitzar sis sèries de deu repeticions de rull femoral unilateral i en van executar només la fase excèntrica amb cada cama. Atès que deu dels tretze participants en l’estudi van patir nivells elevats de dany muscular, els resultats desafien la noció segons la qual el dany muscular greu en humans es limita a protocols d'estimulació elèctrica. També es van observar diferències en la comparació entre extremitats, fet que va revelar que els dissenys experimentals que utilitzen l’extremitat contralateral com a control han de tenir en compte que es poden induir diversos graus de dany sobre la musculatura isquiotibial en ambdues cames d’un mateix subjecte. A més, la creatina quinasa mitocondrial del sarcòmer (sMtCK) sembla ser un nou i prometedor biomarcador d’EIMD que permet la identificació de high responders. Finalment, quan es recupera la funció muscular, increments persistents del temps de relaxació transversal (T2) suggereixen un procés d'adaptació/remodelació més que no pas dany muscular. Exercici de llarga durada El primer estudi d’LDE (IV) aplica el model molecular indirecte de dany muscular per avaluar la resposta del múscul després d’una ultramarató de muntanya (MUM) en vuit atletes (amateurs) entrenats en disciplines de resistència. Els resultats permeten concloure que l'augment de la concentració en sèrum d’SM després d’una MUM podria ser una evidència indirecta de disrupcions selectives del sarcòmer de fibres lentes (tipus I). Finalment, a l'últim estudi (V) basat en protocols d’LDE es van comparar els canvis induïts per una cursa de muntanya de 35 km (MTR) i una MUM de 55 km en els nivells sèrics de biomarcadors de dany muscular. La mostra de l’estudi es va compondre d’un grup de deu homes (amateurs) entrenats en disciplines de resistència, que van competir a l’MTR, i d’un altre grup de sis homes amb nivells elevats d’entrenament, que van competir a la MUM. Els resultats indiquen que la major distància recorreguda a la MUM podria estar relacionada amb nivells superiors de dany muscular de les fibres lentes (tipus I), fins i tot en individus altament entrenats.[eng] The aim of this thesis was to characterize lower limb exercise-induced muscle damage (EIMD) by analysing the time course and the magnitude of activity or concentration change of serum biochemical markers. For that purpose, lower limb EIMD was assessed by laboratory high intensity exercise (HIE) protocols (studies I, II and III) and field long duration exercise (LDE) protocols (studies IV and V). High intensity exercise In the first study (I), muscle damage induced by high intensity inertial half-squat exercise performed on a flywheel device was assessed through the serum evolution of muscle enzymes and fiber type-specific sarcomere proteins such as fast (type II) and slow (type I/ß) myosin (FM and SM respectively). Serum profiles were recorded at baseline and at different time points after exercise in ten healthy, physically active young men. The increase in serum muscle enzymes suggests increased membrane permeability of both fast (type II) and slow (type I) fibers, and the increase in FM reveals sarcomere disruption as well as increased membrane permeability of fast (type II) fibers. We concluded that an indirect molecular model of muscle damage could be constructed by measuring the time course of serum activity or concentration of muscle enzymes and proteins, according to their molecular weight, the fiber compartment in which they are located, and the fiber type (fast [type II] or slow [type I]) in which they are expressed. During the second study (II) we applied the indirect molecular model of EIMD to assess the muscle response. Specifically, in a trained pole vaulter (PV) and a physical education student (PE), we investigated the effect of a leg press exercise leading to failure (LPF) on changes in serum activity of muscle enzymes and serum concentration of FM and SM, while simultaneously examining mechanical output components as indicators of the performance and fatigue developed throughout the exercise. The PV’s exercise output revealed an explosive (power-oriented) profile leading to selective mild damage of fast fibers. In contrast, the PE exercise output showed a fatigue-resistant profile, which induced greater muscle enzyme activity and SM serum concentration, suggesting a higher extent of slow fiber damage. In the last HIE study (III), we investigated the degree of damage inflicted on the hamstring muscles by an intensive voluntary eccentric exercise. We analysed differences in the extent of damage between-subjects and within-subjects (limb-to-limb comparison). To do so, we assessed the relationship between serum biomarkers and other indirect markers of muscle damage. Thirteen males performed six sets of ten reps of eccentric unilateral leg curl with each leg. Results from this study challenge the notion that severe EIMD in humans is restricted to electrical stimulation protocols, since ten (‘high responders’) out of a total of thirteen subjects suffered severe muscle damage. Within-subject (limb-to-limb comparison) differences were also observed, revealing that experimental designs using contralateral limbs as a control should consider that different degrees of hamstring damage can be induced in the two legs. Sarcomeric mitochondrial creatine kinase (sMtCK) is a promising novel EIMD biomarker that allows identification of high responders. Finally, when muscle function is recovered, long-lasting increases in transverse relaxation time (T2) values suggest an adaptive process rather than damage. Long duration exercise The first LDE study (IV) applied the indirect molecular model of EIMD to assess the muscle response after mountain ultramarathon (MUM) in eight endurance-trained amateur athletes. From the results, we concluded that the increase in SM serum concentration after MUM may be indirect evidence of slow (type I) fiber-specific sarcomere disruptions. Finally, the last study (V) based on LDE protocols compared serum changes of biomarkers of EIMD after a 35-km mountain trail race (MTR) and a 55-km MUM. The sample was composed of one group of ten amateur trained male athletes who ran a 35-km MTR and another group of six highly trained male athletes who ran a 55-km MUM. The results indicate that mountain running distance is related to deeper slow (type I) muscle fiber damage, even in highly trained individuals

Integrating external and internal load for monitoring fitness and fatigue status in standard microcycles in elite rink hockey

The aims of this study were 3-fold: firstly, to present an integrative approach to external and internal load dynamics for monitoring fitness and fatigue status of specific in-court rink hockey training sessions in a standard microcycle; secondly, to assess the differences between training sessions and matches; the third and final aim was to assess the association between external and internal load metrics. The external load, using a local positioning system, and internal load, using the declared rate of perceived exertion, were measured during 23 in-season microcycles for nine top-level players. Training load data were analysed with regard to the number of days before or after a match [match day (MD) minus or plus]. In relation to the first aim, internal and external load metrics merged into a single integrated system using pooled data z-scores provided an invisible monitoring tool that places the players in the fitness-fatigue continuum throughout the different microcycle sessions. In this regard, MD-4 and MD-1 sessions tend to place, with a low dispersion, the players in a 'low external and internal load' zone. On the contrary, in MD-3 and MD-2 sessions, as well as in MD, in which higher loads were recorded, most of the players were within a 'high external and internal load' zone with a tendency towards dispersion towards the fitness or fatigue zones. Finally, and with regard to the second and third aims, an inverted 'U-shape' load dynamic related to the specific goals of each training session was the main finding in terms of comparison between MD; a load peak between MD-3 and MD-2 sessions and a significant decrease in all the load variables in MD-1 sessions were found; and high-to-low correlations were found between external and internal load metrics. This study presents an integrative approach to the external and internal load of players for monitoring fitness and fatigue status during a standard microcycle in rink hockey that might provide team sport staff members with a deeper understanding of load distribution in the microcycle in relation to the matc

Early functional and morphological muscle adaptations during short-term inertial-squat training

Purpose: To assess early changes in muscle function and hypertrophy, measured as increases in muscle cross-sectional areas (CSAs) and total volume, over a 4 weeks inertial resistance training (RT) program. Methods: Ten young RT-naive volunteers (age 23.4 4.1 years) underwent 10 training sessions (2-3 per week) consisting of five sets of 10 flywheel squats (moment of inertia 900 kg cm2). Magnetic resonance imaging (MRI) scans of both thighs were performed before (PRE), and after 2 (IN) and 4 (POST) weeks of training to compute individual muscle volumes and regional CSAs. Scans were performed after 96 h of recovery after training sessions, to avoid any influence of acute muscle swelling. PRE and POST regional muscle activation was assessed using muscle functional MRI (mfMRI) scans. Concentric (CON) and eccentric (ECC) squat force and power, as well as maximal voluntary isometric contraction force (MVIC) of knee extensors and flexors, were measured in every training session. Results: Significant quadriceps hypertrophy was detected during (IN: 5.5% 1.9%) and after (POST: 8.6% 3.6%) the training program. Increases in squat force (CON: 32% 15%, ECC: 31 15%) and power (CON: 51% 30%, ECC: 48% 27%) were observed over the training program. Knee extensor MVIC significantly increased 28% 17% after training, but no changes were seen in knee flexor MVIC. No correlation was found between regional muscular activation in the first session and the % of increase in regional CSAs (r = -0.043, P = 0.164). Conclusion: This study reports the earliest onset of whole-muscle hypertrophy documented to date. The process initiates early and continues in response to RT, contributing to initial increases in force. The results call into question the reliability of mfMRI as a tool for predicting the potential hypertrophic effects of a given strengthening exercise

Anàlisi de la capacitat d’acceleració en dones atletes de modalitats de velocitat

Objectius. Caracteritzar la capacitat d’acceleració en relació amb el rendiment (temps en esprint de 30 m), la velocitat màxima i les manifestacions de força (capacitat de salt) i potència (en mig esquat) musculars en quatre dones atletes d’especialitats de velocitat d’àmbit nacional. Mètodes. Es van fer dos dies de proves (pista i laboratori). Es va valorar la capacitat d’acceleració (velocitats instantània a 1, 2 i 3 s –vi1, vi2 i vi3–), acceleració inicial (ainicial), temps d’esprint en 30 metres (rendiment), velocitat màxima (vmàx), capacitat de salt (SJ, CMJ, LJ bw i RJ 5s) i potència mitjana màxima (Pm màx) desenvolupada en mig esquat. Resultats. Es van trobar correlacions significatives entre el rendiment (t30m) i la vmàx (r = –0,980; P < 0,01), la capacitat d’acceleració (velocitats instantànies) i el t30m (r = –0,954; P < 0,05) i la vmàx (r = 0,992 i 0,979; P < 0,01 i 0,05), la manifestació elàstica de la força (CMJ) i el t30m (r = –0,983; P < 0,05), i la força dinàmica màxima relativa i la ainicial (r = 0,980; P < 0,01). Conclusions. La principal troballa d’aquest estudi va ser que la vmàx era el major determinant del t30m. També la capacitat d’acceleració, sobretot la vi2, i el CMJ van tenir una gran ascendència sobre el t30m i la vmàx

Análisis de la capacidad de aceleración en mujeres atletas de modalidades de velocidad

Objetivos. Caracterizar la capacidad de aceleración con relación al rendimiento (tiempo en sprint de 30 m), la velocidad máxima y las manifestaciones de fuerza (capacidad de salto) y potencia (en ½ squat) musculares en 4 mujeres atletas de especialidades de velocidad de nivel nacional. Métodos. Se realizaron dos días de pruebas (pista y laboratorio). Se valoró la capacidad de aceleración (velocidades instantánea a 1, 2 y 3 s –vi1, vi2 i vi3–), aceleración inicial (ainicial), tiempo de sprint en 30 m (rendimiento), velocidad máxima (vmàx), capacidad de salto (SJ, CMJ, LJ bw y RJ 5s) y potencia media máxima (Pm màx) desarrollada en ½ squat. Resultados. Se hallaron correlaciones significativas entre el rendimiento (t30m) y la vmáx (r = –0,980; P < 0,01), la capacidad de aceleración (velocidades instantáneas) y el t30m (r = –0,954; P < 0,05) y la vmáx (r = 0,992 y 0,979; P < 0,01 y 0,05), la manifestación elástica de la fuerza (CMJ) y el t30m (r = –0,983; P < 0,05) y la fuerza dinámica máxima relativa y la ainicial (r = 0,980; P < 0,01). Conclusiones. El principal hallazgo del presente estudio fue que la vmáx era el mayor determinante del t30m. También la capacidad de aceleración, sobretodo la vi2, y el CMJ tuvieron una gran ascendencia sobre el t30m y la vmáx

Apunts. Educació física i esports

Resumen tomado de la publicaciónObjetivos. Caracterizar la capacidad de aceleración con relación al rendimiento (tiempo en sprint de 30 m), la velocidad máxima y las manifestaciones de fuerza (capacidad de salto) y potencia musculares en 4 mujeres atletas de especialidades de velocidad de nivel nacional. Métodos. Se realizaron dos días de pruebas (pista y laboratorio). Se valoró la capacidad de aceleración, aceleración inicial (ainicial), tiempo de sprint en 30 m (rendimiento), velocidad máxima (vmàx), capacidad de salto (SJ, CMJ, LJ bw y RJ 5s) y potencia media máxima (Pm màx) desarrollada en medio squat. Resultados. Se hallaron correlaciones significativas entre el rendimiento (t30m) y la vmáx, la capacidad de aceleración (velocidades instantáneas) y el t30m y la vmáx, la manifestación elástica de la fuerza (CMJ) y el t30m y la fuerza dinámica máxima relativa y la ainicial. Conclusiones. El principal hallazgo del presente estudio fue que la vmáx era el mayor determinante del t30m. También la capacidad de aceleración, sobretodo la vi2, y el CMJ tuvieron una gran ascendencia sobre el t30m y la vmáx.CataluñaUniversidad Pública de Navarra. Biblioteca; Campus de Arrosadía; 31006 Pamplona; Tel. +34948169060; Fax +34948169069; [email protected]

Assessment of muscle fiber adaptation in footballers using a new ELISA assay of myosin isoforms

BACKGROUND: To measure the impact of training models on injury incidence, data of health and performance were integrated to study fiber adaptation during a competitive season. We studied football players over a season, analyzing hours of exposure to sport by serum changes in fast and slow myosin, creatine kinase and lactate dehydrogenase. METHODS: A new assay was developed to measure the myosin isoforms in 49 non-sporting volunteers and in 27 professional football players. RESULTS: Myosin isoforms in volunteers with mean ages of 30±8 were 1553 µg/L fast and 1284 µg/L slow; in the group with of 56±7 were 1426 µg/L fast and 1046 µg/L slow. Slow myosin was significantly lower in older subjects (-18%). Samples from the players in preseason had lower mean scores for fast myosin (1123 µg/L) and higher for slow myosin (2072 µg/L) than reference volunteers. During the season, myosins reached the maximum with the maximum load (1537 µg/L fast, 2195 µg/L slow but decreased and adapted to the high level of demand (425 µg/L fast, 1342 µg/L slow). CK and LDH were maximal at the pre-season (227 U/L, 333 U/L) while myosin levels were maximal at the beginning of season (1537 µg/L, 2195 µg/L). CONCLUSIONS: Measuring serum myosin isoforms we identify the type and amount of damage caused by training and matches, making it a new control tool capable of advising training towards a minimum of blood slow myosin but controlling the fast fiber participating and be able to improve the performance of the players

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

Consequences of running mountain races on muscle damage were investigated by analysing serum muscle enzymes and fibre-type-specific sarcomere proteins. We studied 10 trained amateur and 6 highly trained runners who ran a 35 km and 55 km mountain trail race (MTR), respectively. Levels of creatine kinase (CK), CK-MB isoform (CK-MB), sarcomeric mitochondrial CK (sMtCK), transaminases (AST and ALT), cardiac troponin I (cTnI) and fast (FM) and slow myosin (SM) isoforms, were assessed before, 1 h, 24 h and 48 h after the beginning of MTR. Significant SM increases were found at 24 h in the 55 km group. Levels of CK, CK-MB, AST and cTnI were significantly elevated in both groups following MTR, but in the 55 km group they tended to stabilize in at 48 h. Using pooled data, time-independent serum peaks of SM and CK-MB were significantly correlated. Moreover, concentration of sMtCK was significantly elevated at 1 and 24 h after the race in the 35 km group. Although training volume could confer protection on the mitochondria, the increase in serum CK-MB and SM in the 55 km group might be related to damage to the contractile apparatus type I fibres. Competing in long-distance MTRs might be related to deeper type I muscle fibre damage, even in highly trained individuals

Assessment of muscle fiber adaptation in footballers using a new ELISA assay of myosin isoforms

BACKGROUND: To measure the impact of training models on injury incidence, data of health and performance were integrated to study fiber adaptation during a competitive season. We studied football players over a season, analyzing hours of exposure to sport by serum changes in fast and slow myosin, creatine kinase and lactate dehydrogenase. METHODS: A new assay was developed to measure the myosin isoforms in 49 non-sporting volunteers and in 27 professional football players. RESULTS: Myosin isoforms in volunteers with mean ages of 30±8 were 1553 µg/L fast and 1284 µg/L slow; in the group with of 56±7 were 1426 µg/L fast and 1046 µg/L slow. Slow myosin was significantly lower in older subjects (-18%). Samples from the players in preseason had lower mean scores for fast myosin (1123 µg/L) and higher for slow myosin (2072 µg/L) than reference volunteers. During the season, myosins reached the maximum with the maximum load (1537 µg/L fast, 2195 µg/L slow but decreased and adapted to the high level of demand (425 µg/L fast, 1342 µg/L slow). CK and LDH were maximal at the pre-season (227 U/L, 333 U/L) while myosin levels were maximal at the beginning of season (1537 µg/L, 2195 µg/L). CONCLUSIONS: Measuring serum myosin isoforms we identify the type and amount of damage caused by training and matches, making it a new control tool capable of advising training towards a minimum of blood slow myosin but controlling the fast fiber participating and be able to improve the performance of the players

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

Consequences of running mountain races on muscle damage were investigated by analysing serum muscle enzymes and fibre-type-specific sarcomere proteins. We studied 10 trained amateur and 6 highly trained runners who ran a 35 km and 55 km mountain trail race (MTR), respectively. Levels of creatine kinase (CK), CK-MB isoform (CK-MB), sarcomeric mitochondrial CK (sMtCK), transaminases (AST and ALT), cardiac troponin I (cTnI) and fast (FM) and slow myosin (SM) isoforms, were assessed before, 1 h, 24 h and 48 h after the beginning of MTR. Significant SM increases were found at 24 h in the 55 km group. Levels of CK, CK-MB, AST and cTnI were significantly elevated in both groups following MTR, but in the 55 km group they tended to stabilize in at 48 h. Using pooled data, time-independent serum peaks of SM and CK-MB were significantly correlated. Moreover, concentration of sMtCK was significantly elevated at 1 and 24 h after the race in the 35 km group. Although training volume could confer protection on the mitochondria, the increase in serum CK-MB and SM in the 55 km group might be related to damage to the contractile apparatus type I fibres. Competing in long-distance MTRs might be related to deeper type I muscle fibre damage, even in highly trained individuals