Repeated simulated match-induced changes in finger flexor force and blood acid-base balance in world-class female judokas
International Journal of Sports Physiology and Performance
Centre for Exercise and Sports Science Research / School of Medical and Health Sciences
Purpose: The aim of this study was to investigate the time course of maximal isometric finger flexor force and blood acid-base balance during repeated simulated matches in world-class judokas. Methods: Seven 21-to 28-year-old world-class female judokas (including Olympic and World Championship medalists) repeated four 4-minute judo combats interspersed by 15 minutes of passive recovery. Maximal voluntary isometric finger flexor contraction (MVIC) force was measured in both hands after warm-up and immediately after each combat using a handgrip dynamometer. MVIC force was classified as MVIC hikite force (pulling hand) and MVIC tsurite force (lifting hand). Results: Blood lactate concentration, pH, bicarbonate concentration, partial pressure of oxygen, and oxygen saturation were measured between 3 and 5 minutes after each match. At completion of the fourth combat, mean MVIC hikite and tsurite force decreased by 18 % and 12 %, respectively (g = 0.23 and 0.29, respectively; P.05), demonstrating that force production was substantial throughout repeated matches. Blood lactate concentration increased 5-fold from 2.69 (1.37) mmol L-1 after warm-up to 13.10 (2.61) mmol L-1 after the last match (g = 4.13, P = .018). Concurrently, blood pH decreased slightly from 7.44 (0.03) to 7.26 (0.05) (g = 2.34, P = .018), that is, by only 0.18 units. The decreased blood pH was significantly correlated with a decrease in bicarbonate concentration (R2 = .94, P.001). Finally, partial pressure of oxygen and oxygen saturation remained unchanged during the judo contest. Conclusions: Female world-class judokas were able to maintain a high level of grip strength in both hands and efficiently regulate blood acid-base balance during repeated simulated high-intensity matches.