Muscle buffer capacity and aerobic fitness are associated with repeated-sprint ability in women

Abstract

In addition to a high aerobic fitness, the ability to buffer hydrogen ions (H+) may also be important for repeated-sprint ability (RSA). We therefore investigated the relationship between muscle buffer capacity (betamin vivo and betamin vitro) and RSA. Thirty-four untrained females [mean (SD): age 19 (1) years, maximum oxygen uptake (VO2peak) 42.3 (7.1) ml x kg(-1) x min(-1)] completed a graded exercise test (GXT), followed by a RSA cycle test (five 6-s sprints, every 30 s). Capillary blood was sampled during the GXT and before and after the RSA test to determine blood pH (pHb) and lactate concentration ([La-]b). Muscle biopsies were taken before (n=34) and after (n=23) the RSA test to determine muscle lactate concentration ([La-]i), hydrogen ion concentration ([H+]i) pHi, betamin vivo and betamin vitro. There were significant correlations between work decrement (%) and betamin vivo (r=-0.72, P<0.05), VO2peak (r=-0.62, P<0.05), lactate threshold (LT) (r=-0.56, P<0.05) and changes in [H+]i (r=0.41, P<0.05). There were however, no significant correlations between work decrement and betamin vitro, or changes in [La-]i, or [La-]b. There were also no significant correlations between total work (J x kg(-1)) during the RSA test and betamin vitro, betamin vivo, or changes in [La-]i, pHi, [La-]b, or pHb. There were significant correlations between total work (J x kg(-1)) and both VO2peak (r=0.60, P<0.05) and LT(r=0.54, P<0.05). These results support previous research, identifying a relationship between RSA and aerobic fitness. This study is the first to identify a relationship between betamin vivo and RSA. This suggests that the ability to buffer H+ may be important for maintaining performance during brief, repeated sprints.

Comparação da potência aeróbia e anaeróbia máxima entre atletas juvenis de basquetebol e handebol

“…Sporiš et al, (2014) A manutenção dos níveis de potência após os sprints pode ser explicada pela capacidade de tamponamento da acidez muscular provocada pela presença elevada dos íons H+, considerada um importante atributo para a CSR (BISHOP; EDGE; GOODMAN, 2004). O aumento no IF é devido mudanças no meio intramuscular relacionado à falta de ATP disponível para o acoplamento entre actina e miosina e pela captação de cálcio pelo retículo sarcoplasmático; diminuição da concentração de glicogênio muscular levando ao aumento de amônia e produção de monofosfato de inosina, que está relacionado ao aumento de lactato muscular e ao decréscimo de fosfocreatina; diminuição do pH muscular que tem sido associado com a inibição da enzima fosfofrutoquinase e redução na glicólise e disfunções no processo de estímulo-contração (MOHR; KRUSTRUP; BANGSBO, 2005).…”

Utilização da distância total percorrida no teste específico de hoff como preditor da velocidade de limiar anaeróbio no futebol

“…In the current soccer, the aerobic system plays an important role in the player's performance, being this energetic system the predominant in the energy supply in most part of the match 3,12 and it also enables fast recovery of the anaerobic systems after high-intensity exercises [2][3][4] . Thus, the aerobic capacity (anaerobic threshold), which corresponds to the highest exercise intensity which presents aerobic predominance and is identified by the highest intensity at which balance between lactate production and removal (maximal lactate steady state) occurs, plays an important role in the physical performance of soccer players.…”

“…Such fact evidences the increase in physical demand during the game and the importance of the aerobic resistance in the physical performance of the athlete. Aerobic fitness in soccer is responsible both for the energy supply in the endurance events, which are predominant in the game, and for the fast recovery after an anaerobic activity [2][3][4] .…”

A influência de variáveis aeróbias e anaeróbias no teste de “sprints” repetidos

“…Until the present moment, few studies have observed that the aerobic parameters such as ventilatory threshold 15 , VO 2 max 15,17,19 , MAV 11 , velocity in which the VO 2 max is reached (vVO 2 max) 13 , tau [19][20] were correlated with RS performance. However, the variables which signi cantly correlates are not always similar among studies, and thus, it is important to highlight that in the present study, as well as others, none aerobic variable correlated with the TT 10,12,16,[21][22]24 .…”

“…However, there seems not to be a consensus regarding the importance of the anaerobic physiological aspects (i.e., cumulated oxygen de cit and blood lactate concentration at post-test) on RS performance, as others researches have demonstrated contradictory results 12,[15][16][17] . In addition to anaerobic parameters, G et al 18 highlighted that the aerobic parameters might in uence the RS performance, insofar as, performing several RS with incomplete recovery increases the energy transfer by the oxidative metabolism.…”