Influence of the biomechanical variables of the gait cycle in running economy. [Influencia de variables biomecánicas del ciclo de paso en la economía de carrera].

<p algn="justify">The aim of this study was to investigate the relationships between biomechanical variables and running economy (RE). Eleven recreational (RR) and 14 well-trained runners (WT) completed 4 min stages on a treadmill at different speeds. During the test, biomechanical variables such as ground contact time (tc), swing time (tsw), stride length, frequency and angle and the length of the different subphases of ground contact were calculated using an optical measurement system. VO2 was measured in order to calculate RE. The WT runners were more economical than the RR at all speeds and presented lower tc, higher tsw, longer strides, lower stride frequencies and higher stride angles (P<0.05). Similarly, the WT runners experienced a later propulsion subphase than the RR runners (P<0.05). RE was positively related to tc, stride frequency and 10-km race pace, whereas it was negatively related to tsw, stride length, stride angle and the propulsive subphase. Our results suggest that running patterns characterized by longer stride lengths and higher stride angles, lower stride frequencies and tc, higher tsw and later propulsion suphases may enable an efficient energy use per stride. </p> Resumen <p align="justify">El objetivo de este estudio fue el investigar las relaciones entre diferentes variables biomecánicas y la economía de carrera (RE). Once atletas populares (RR) y 14 atletas altamente entrenados (WT) completaron estadios de 4 min en tapiz rodante a diferentes velocidades. Durante el test, el tiempo de contacto (tc) y de vuelo (tsw), la longitud, frecuencia y ángulo de zancada y la duración de las diferentes sub-fases del tiempo de contacto se calcularon usando un sistema óptico. Se midió el VO2 para calcular la RE. Los atletas WT fueron más económicos que los RR y presentaron menores tc, mayores tsw, zancadas más largas, frecuencias más bajas y ángulos mayores (P<0.05). Además, los atletas WT experimentaron la sub-fase propulsiva más tarde que los RR (P<0.05). La RE estuvo positivamente relacionada con el tc, la frecuencia de zancada y el ritmo de 10 km, mientras que estuvo negativamente relacionada con el tsw, longitud y ángulo de zancada y la sub-fase propulsiva. Estos resultados sugieren que una biomecánica caracterizada por zancadas más largas, ángulos de zancada y tsw mayores, menores frecuencias y tc, y sub-fases propulsivas más tardías pueden favorecer un uso energético más eficiente.</p

Barne karga metodoen alderaketa eta planifikazioaren analisia futbolean.

205 p.HELBURUA: Ikerlan honen helburu orokorra, barne kargaren kontrolean oinarrituz futboleko entrenamendu prozesuaren monitorizazioa eta planifikazioa aztertzea da. Horretarako ezarririko helburu espezifikoak, barne kargaren kontrolerako metodo ezberdinen arteko alderaketa burutzea eta planifikazio maila ezberdinetan sakontzea izan dira, lehiaketak hauetan dituen eraginak aztertuz.METODOLOGIA: Ikerketan Athletic Club B taldeko 20 jokalarik parte hartu dute eta 2012-2013 denboraldian burutu da, aurreneko bi mesozikloetako 62 entrenamendu eta 10 lagunartekoetan zehar 933 bihotz maiztasun (BM) eta hautemandako neke erlatiboaren (RPE) bidez 800 erregistro jasoz. Barne karga neurtzeko metodoen alderaketa Edwards-en TRIMP (1993), Stagno eta lankideen TRIMP (2007) eta Foster-ren sRPE (1998) metodoen arteko korrelazio indibidualak eta kolektiboaren bidez egin da; barne kargaren analisia, berriz, futboleko entrenamendu prozesua osatzen duten planifikazio unitateen konparaketak eta dinamikak aztertuz, karga, bolumen eta intentsitate ezaugarrietan sakontzen.EMAITZAK: Barne karga kontrolatzeko metodoen alderaketari dagokionez, Stagno-ren, Edwards-en eta sRPE metodoen arteko korrelazio oso esanguratsuak ikusi dira jokalari ia guztietan, hauek ahulagoak izanik sRPE eta BM-ean oinarrituriko metodoen artean (sRPE-Stagno erlazioan, r = 0,251-0,898, p < 0,05; sRPE-Edwards erlazioan, r = 0,311-0,891, p < 0,05), BM-ean oinarrituriko metodoen artean baino (r = 0,954-0,990, p < 0,05). Talde korrelazioetan, Edwards-en TRIMP metodoak erlazio sendoagoa erakutsi du sRPE metodoarekin (r = 0,710, p < 0,001) Stagno-ren TRIMP metodoak baino (r = 0,655, p < 0,001).Planifikazio unitate ezberdinetako barne kargaren analisiari dagokionez, desbideratze estandar zabalen argitara taldearen entrenamendu saioetan jokalariek estimulu kondizional ezberdinak jasaten dituztela esan daiteke. Lehiaketak edozein saio baino estimulu kondizional bortitzagoa suposatzen du, mikrozikloetako kargaren dinamikan eraginez. Saio eta mikroziklo mota ezberdinen artean ez dira erabateko ezberdintasun bereizgarririk ageri, bai ordea norabide ezberdinetako joerak. Mesoziklo mailan, metaketakoan barne karga altuagoak pilatzen dira eraldaketakoan baino, baina mesoziklo bakoitzeko saioen bataz bestekoak antzekoak dira.ONDORIOAK: Futboleko barne karga monitorizatzeko adierazle egokiena sRPE metodoa da, eta BM erregistroak futbol entrenamenduen intentsitatearen adierazle egokiak izatea zalantzan jarri daiteke, entrenamendu estimuluak indibidualizatzeko lagungarriak diren arren. Entrenamendu karga egokiak izan eta errendimendu maila optimoak izateko, estimulu kondizionalaren kontrol indibiduala ezinbestekoa da, saio, mikroziklo eta mesozikloetako karga pilaketak maneiatuz

Onset of blood lactate accumulation as a predictor of performance in top athletes

The main purpose of this study was to investigate whether the onset of blood lactate accumulation velocity (VOBLA) is a good predictor of middle- and long-distance running performance in well-trained endurance runners. Twenty-two well-trained runners participated in this study. All participants completed a incremental test on a treadmill to determine maximal physiological variables the VOBLA (4 mmol·L-1 of lactate concentration). The relationships between VOBLA and the best 10-km (V10K) and 3-km (V3K) race pace were analyzed. The velocity for VOBLA was 17.7 ± 1.2 km·h-1 and the velocities for V10K and V3K were 21.1 ± 0.7 km·h-1 and 19.0 ± 0.8 km·h-1, respectively. A positive linear relationship was found between VOBLA and V10K (r = 0.761, P < 0.05) and between VOBLA and V3K (r = 0.561, P < 0.05). These results indicate that VOBLA is highly associated to running performance according to V10K and V3K in well-trained runner

DIFFERENCES IN GROUND CONTACT TIME EXPLAIN THE LESS EFFICIENT RUNNING ECONOMY IN NORTH AFRICAN RUNNERS

The purpose of this study was to investigate the relationship between biomechanical variables and running economy in North African and European runners. Eight North African and 13 European male runners of the same athletic level ran 4-minute stages on a treadmill at varying set velocities. During the test, biomechanical variables such as ground contact time, swing time, stride length, stride frequency, stride angle and the different sub-phases of ground contact were recorded using an optical measurement system. Additionally, oxygen uptake was measured to calculate running economy. The European runners were more economical than the North African runners at 19.5 km · h-1, presented lower ground contact time at 18 km · h-1 and 19.5 km · h-1 and experienced later propulsion sub-phase at 10.5 km · h-1, 12 km · h-1, 15 km · h-1, 16.5 km · h-1 and 19.5 km · h-1 than the European runners (P<0.05). Running economy at 19.5 km · h-1 was negatively correlated with swing time (r=-0.53) and stride angle (r=-0.52), whereas it was positively correlated with ground contact time (r=0.53). Within the constraints of extrapolating these findings, the less efficient running economy in North African runners may imply that their outstanding performance at international athletic events appears not to be linked to running efficiency. Further, the differences in metabolic demand seem to be associated with differing biomechanical characteristics during ground contact, including longer contact times

Comienzo de la acumulación de lactato sanguíneo como predictor del rendimiento en atletas de élite

The main purpose of this study was to investigate whether the onset of blood lactate accumulation velocity (VOBLA) is a good predictor of middle- and long-distance running performance in well-trained endurance runners. Twenty-two well-trained runners participated in this study. All participants completed a incremental test on a treadmill to determine maximal physiological variables the VOBLA (4 mmol·L-1 of lactate concentration). The relationships between VOBLA and the best 10-km (V10K) and 3-km (V3K) race pace were analyzed. The velocity for VOBLA was 17.7 ± 1.2 km·h-1 and the velocities for V10K and V3K were 21.1 ± 0.7 km·h-1 and 19.0 ± 0.8 km·h-1, respectively. A positive linear relationship was found between VOBLA and V10K (r = 0.761, P < 0.05) and between VOBLA and V3K (r = 0.561, P < 0.05). These results indicate that VOBLA is highly associated to running performance according to V10K and V3K in well-trained runners..El objetivo principal de este estudio fue investigar si el comienzo de la acumulación de lactato en sangre (VOBLA) es un buen predictor del rendimiento de mediofondo y fondo en atletas entrenados. Veintidós corredores tomaron parte en este estudio. Todos completaron un test máximo incremental en tapiz rodante para determinar los parámetros fisiológicos máximos así como la VOBLA. Se analizaron las relaciones entre la VOBLA y el ritmo de carrera de 10 km (V10K) y 3 km (V3K). La VOBLA fue de 17.7 ± 1.2 km·h-1 y las V10K y V3K fueron 21.1 ± 0.7 km·h-1 y 19.0 ± 0.8 km·h-1, respectivamente. Se encontró una correlación lineal significativa entre la VOBLA y V10K (r = 0.761, P < 0.05) y entre VOBLA y V3K (r = 0.561, P < 0.05). Estos resultados indican que la VOBLA está altamente asociada al rendimiento de la carrera de acuerdo a V10K yV3K en atletas entrenados

Influence of the biomechanical variables of the gait cycle in running economy

The aim of this study was to investigate the relationships between biomechanical variables and running economy (RE). Eleven recreational (RR) and 14 well-trained runners (WT) completed 4 min stages on a treadmill at different speeds. During the test, biomechanical variables such as ground contact time (tc), swing time (tsw), stride length, frequency and angle and the length of the different subphases of ground contact were calculated using an optical measurement system. VO2 was measured in order to calculate RE. The WT runners were more economical than the RR at all speeds and presented lower tc, higher tsw, longer strides, lower stride frequencies and higher stride angles (P<0.05). Similarly, the WT runners experienced a later propulsion subphase than the RR runners (P<0.05). RE was positively related to tc, stride frequency and 10-km race pace, whereas it was negatively related to tsw, stride length, stride angle and the propulsive subphase. Our results suggest that running patterns characterized by longer stride lengths and higher stride angles, lower stride frequencies and tc, higher tsw and later propulsion suphases may enable an efficient energy use per stride.El objetivo de este estudio fue el investigar las relaciones entre diferentes variables biomecánicas y la economía de carrera (RE). Once atletas populares (RR) y 14 atletas altamente entrenados (WT) completaron estadios de 4 min en tapiz rodante a diferentes velocidades. Durante el test, el tiempo de contacto (tc) y de vuelo (tsw), la longitud, frecuencia y ángulo de zancada y la duración de las diferentes sub-fases del tiempo de contacto se calcularon usando un sistema óptico. Se midió el VO2 para calcular la RE. Los atletas WT fueron más económicos que los RR y presentaron menores tc, mayores tsw, zancadas más largas, frecuencias más bajas y ángulos mayores (P<0.05). Además, los atletas WT experimentaron la sub-fase propulsiva más tarde que los RR (P<0.05). La RE estuvo positivamente relacionada con el tc, la frecuencia de zancada y el ritmo de 10 km, mientras que estuvo negativamente relacionada con el tsw, longitud y ángulo de zancada y la sub-fase propulsiva. Estos resultados sugieren que una biomecánica caracterizada por zancadas más largas, ángulos de zancada y tsw mayores, menores frecuencias y tc, y sub-fases propulsivas más tardías pueden favorecer un uso energético más eficiente