Repeated Treadmill Sprints Impair Cognitive Performance in Amateur Team-Sport Athletes When Performed in Normobaric Hypoxia.

This study determined if a single bout of repeated-sprint running under hypoxic (RSH) conditions was associated with impaired cognitive function when compared with repeated-sprint running under normoxic (RSN) conditions. Eleven amateur team-sport athletes performed a repeated-sprint running protocol (4 sets of 4, 4-s all-out sprints; i.e., RSR444) under both conditions (14.5% and 20.9% O2) on a non-motorized treadmill. Changes in SpO2, pre-frontal cortex total haemoglobin (Δ[THb]), oxyhaemoglobin (Δ[O2Hb]), deoxyhaemoglobin (Δ[HHb]) and cognitive function (detection task: DET; identification task: IDN; one card learning task: OCL; performed pre and 20 min post RSR444) were examined. During RSH, SpO2 was lower following each set (p ≤ 0.05), while [HHb] was higher after each set (p ≤ 0.05) compared with RSN. In addition, while there was no effect of condition on DET (p = 0.20) or IDN (p = 0.14), OCL accuracy was lower after, compared with before, RSH (p=0.04), but not RSN (p = 0.52). A significant relationship was observed between Δ[HHB] and ΔOCL accuracy (r = -0.68, p = 0.01). Performance of a single bout of RSH with 14.5% O2 resulted in impaired cognitive function in amateur team-sport athletes. Coaches should be mindful of timing of RSH prescription with regard to other training sessions that challenge speed and movement accuracy.

Mindfulness training attenuates the increase in salivary cortisol concentration associated with competition in highly trained wheelchair-basketball players.

This study determined the effect of 8 wk of mindfulness training (MT) on salivary cortisol (sCort) and rate of salivary Immunoglobulin-A (sIgA) secretion in wheelchair-basketball players during a competition period. The mindful group completed 8 weeks of MT in addition to training and competition. sCort and rate of sIgA secretion were measured at baseline, at 2-week intervals, the end and 2 weeks following the intervention. A significant time and group interaction was observed for sCort (F = 3.297, P = 0.040, ES = 0.191); sCort increased in the control group from MT-BL to MT-2wk (P = 0.001) and remained significantly elevated at MT-4wk (P = 0.013) and MT-6wk (P = 0.002). sCort decreased from MT-6wk to MT-8wk (P < 0.001) and concentrations were not different at MT-8wk and Post-2wk to MT-BL (P > 0.05). Mindful group sCort increased from MT-BL to MT-2wk (P = 0.042) but decreased to concentrations no different to MT-BL for the rest of the intervention period (P > 0.05). There were no group differences in rate of sIgA secretion during the intervention (P = 0.810). It was concluded that 8 weeks of MT attenuated the increase in sCort associated with the competition period.

Reliability of salivary cortisol and immunoglobulin-A measurements from the IPRO® before and after sprint cycling exercise.

BACKGROUND: The purpose of this study was to evaluate the inter-day reliability of the IPRO method for determining resting and postexercise salivary cortisol (sCort) and rate of salivary Immunoglobulin-A (sIgA) secretion. METHODS: Fourteen males (32±11 years) performed two trials (T1 and T2) separated by 7 d, comprising saliva sampling before and 15 min after completion of two, 30-s Wingate Anaerobic Tests separated by 3.5 min (2 x WAnT). sCort increased after the 2 x WAnT in both trials (T1: P<0.001; T2: P<0.001), whereas rate of sIgA secretion decreased in both trials (T1: P=0.002; T2: P=0.002). RESULTS: The intraclass correlation coefficients for resting and postexercise sCort and rate of sIgA secretion ranged from 0.96-0.99. Mean reliability, expressed as the coefficient of variation (%) and the typical error of measurement over the two trials were resting sCort 9.4%, 0.14 ng·mL-1 (9% CI: 0.1-0.2), postexercise sCort 11.9%, 0.44 ng·mL-1 (9% CI: 0.3-0.7), resting rate of sIgA secretion 7.4%, 85.5 µg·mL-1·min-1 (9% CI: 65.2-127.1) and postexercise rate of sIgA secretion 10.5%, 82.9 µg·mL-1·min-1 (9% CI: 63.2-123.1). CONCLUSIONS: The IPRO is a reliable method for determining sCort and rate of sIgA secretion at rest and after sprint-cycling exercise.

Indices of cognitive function measured in rugby union players using a computer-based test battery.

The purpose of this study was to investigate the intra- and inter-day reliability of cognitive performance using a computer-based test battery in team-sport athletes. Eighteen elite male rugby union players (age: 19 ± 0.5 years) performed three experimental trials (T1, T2 and T3) of the test battery: T1 and T2 on the same day and T3, on the following day, 24 h later. The test battery comprised of four cognitive tests assessing the cognitive domains of executive function (Groton Maze Learning Task), psychomotor function (Detection Task), vigilance (Identification Task), visual learning and memory (One Card Learning Task). The intraclass correlation coefficients (ICCs) for the Detection Task, the Identification Task and the One Card Learning Task performance variables ranged from 0.75 to 0.92 when comparing T1 to T2 to assess intraday reliability, and 0.76 to 0.83 when comparing T1 and T3 to assess inter-day reliability. The ICCs for the Groton Maze Learning Task intra- and inter-day reliability were 0.67 and 0.57, respectively. We concluded that the Detection Task, the Identification Task and the One Card Learning Task are reliable measures of psychomotor function, vigilance, visual learning and memory in rugby union players. The reliability of the Groton Maze Learning Task is questionable (mean coefficient of variation (CV) = 19.4%) and, therefore, results should be interpreted with caution.