Physiological Responses to Repeated Running Sprint Ability Tests: A Systematic Review.

The purpose of this study was to review acute physiological responses induced by repeated running sprint ability (RRSA) tests that could serve as references for practitioners utilising repeated sprints as a performance measure with athletes. This research was conducted following the PRISMA methodology. The systematic search was conducted in November 2019 and yielded 26 different scientific articles. Only peer-reviewed full-text article were included as abstracts are too short to allow proper explanation of the RRSAT methodology that was employed. According to the present literature, practitioners should use the following assessments: the 6×40m RRSA protocol with one Change of Direction (COD) (20+20 m with a 180° COD) and 25s of passive recovery between sprints with soccer players; the Intensive Repeated Sprint Ability (IRSA) test with men basketball players; the Futsal Intermittent Endurance Test (FIET) with futsal players; the Repeated Shuttle Sprint Test (RSST) with men handball players; and the Multiple Repeated Sprint Ability test for Badminton players (MRSAB). The present review should serve as a reference standard for RRSA tests. Further research should be directed towards creating and validating more specific RRSA tests protocols to each sports physiological and physical demands.

The Relationship of VO2 Peak and the Blood Lactate Transition Threshold with Metabolic Syndrome and Its Component Disorders.

Background: Improvements in cardiorespiratory fitness attenuate the risk for metabolic syndrome (MetS). However, the determinants of cardiorespiratory fitness measurements such as oxygen consumption (VO2) peak and anaerobic threshold (AT) have not been investigated in persons with MetS. Therefore, the main aim of this study was to compare VO2 peak and AT between subjects with and without MetS and to investigate determinants of cardiorespiratory fitness and its effects on the odds for MetS and its individual components. Methods: Thirty-one males with MetS and 24 healthy male participants each performed a VO2 peak and a blood lactate transition threshold test. Waist circumference, body mass index (BMI), blood pressure, fasting plasma triglyceride, total cholesterol, high-density lipoprotein cholesterol, glucose, and insulin levels were measured. Separate multivariable linear regression models were developed in which VO2 peak, AT, and the components of MetS were used as the dependent variables, while a multivariable logistic regression model was used for MetS. Results: The VO2 peak [median (interquartile range)] was lower in subjects with MetS compared with controls [27.9 (23.0-31.0) vs. 35.0 (32.0-45.0) mL·min-1·kg-1; P < 0.0001]. Multivariable regression analysis demonstrated that there was a bidirectional association between MetS and VO2 peak that was mediated by waist circumference and blood pressure. The VO2 peak was a strong negative determinant of waist circumference (ß = -0.36, P < 0.0001), but not of BMI (ß = -0.13, P = 0.21). Conclusions: A higher VO2 peak is associated with a lower odds ratio for MetS, which is related to greater cardiorespiratory fitness in a cyclical relationship that is mediated by blood pressure and waist circumference. A higher VO2 peak is specifically associated with lower waist circumference, and vice versa, possibly by effects on visceral fat.

INFLUENCE OF LOW GLYCOGEN STORAGE ON BLOOD GLUCOSE AND BLOOD LACTATE KINETICS DURING INCREMENTAL RUNNING TEST / 体力科学

Blood lactate kinetics is an important physiological determinant of endurance exercise performance. Recently, some studies reported that the blood glucose transition point can also be observed (blood glucose threshold; GT) and the GT is consistent with the lactate threshold (LT). However, we have recently reported that blood glucose kinetics and blood lactate kinetics were different during two sets of incremental running tests in the same day. This result suggested that influence of low glycogen storage on GT and LT are different. This study was intended to clarify the effect of low glycogen storage on the blood glucose and the blood lactate kinetics during incremental running test performed two successive days. Eight male endurance runners participated in incremental running test performed two successive days. The main finding was that the blood glucose was significantly lower in the second day than the first day during incremental test, although blood glucose was not different at rest in both days. However, blood lactate was not different form rest to fifth stages in both days, significantly lower only at the final stage in the second day than the first day. Respiratory exchange ration were lower in the second day compared to the first day. GT was significantly higher in the second day than the first day, but LT was not different in both days. We concluded that low glycogen storage effected blood glucose kinetics more than blood lactate kinetics, and resulted in only the change of GT.