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This study aimed to determine if the Garmin Vector (Schaffhausen, Switzerland) power meter produced acceptable measures when compared with the Schoberer Rad Messetechnik (SRM; Julich, Germany) power meter across a range of high-intensity efforts. Twenty-one well-trained cyclists completed power profiles (seven maximal mean efforts between 5 and 600 s) using Vector and SRM power meters. Data were compared using assessments of heteroscedasticity, "t" tests, linear regression, and typical error of estimate (TEE). The data were heteroscedastic, whereby the Vector pedals increasingly overestimated values at higher power outputs; however, "t" tests did not identify any significant differences between power meters (p > 0.05). Using linear regression, Vector data were fit to an SRM equivalent (slope = 0.99; intercept = -9.87) and TEE produced by this equation was 3.3% (3.0%-3.8%). While the data shows slight heteroscedasticity due to differing strain-gauge placement and resultant torque measurement variance, the Vector appears acceptable for measures of power output across various cycling efforts.

The current study investigated the effects of wearing whole-body compression garments (WBCGs) on prolonged high-intensity intermittent exercise (PHIIE) performance. Eight male team-sport athletes ([[bar.X] [+ or -] SD] 20.6 [+ or -] 1.2 years; 72.9 [+ or -] 5.9 kg; 57.5 [+ or -] 3.7 ml x [kg.sup.-1] x [min.sup.-1]) completed a prescribed 45-minute PHIIE protocol on a nonmotorized treadmill in randomly assigned WBCG and control (typical soccer apparel) conditions. Subjects were given verbal and visual cues for movement categories, and they followed set target speeds, except when instructed of a variable run or sprint where the aim was to run as fast as possible. Total distance, velocity-specific distance, and high-intensity self-paced running speeds were taken as performance indicators. Heart rate, [[??]o.sub.2], tissue oxygenation index (TOI), and tissue hemoglobin index (nTHi) were continuously monitored across the protocol. Blood-lactate concentration ([[BLa.sup.-]]]) was measured every 15 minutes. Magnitude-based inferences suggested that wearing WBCGs provided moderate strength likely improvements in total distance covered (5.42 [+ or -] 0.63 vs. 5.88 [+ or -] 0.64 km; 88:10:2%; and [[eta].sup.2] = 0.6) and low-intensity activity distance (4.21 [+ or -] 0.51 vs. 4.56 [+ or -] 0.57 km; 83:14:3%; and [[eta].sup.2] = 0.6) compared with the control. A similar likely increase was also observed in the average TOI of the WBCG condition (53.5 [+ or -] 8.3% vs. 55.8 [+ or -] 7.2%; 87:11:2%; and [[eta].sup.2] = 0.6). The current data demonstrated that wearing WBCGs likely increased physical performance, possibly because of improvements in muscle oxygenation and associated metabolic benefits. Therefore, wearing WBCGs during PHIIE may benefit the physical performance of team-sport athletes by likely metabolic changes within the muscle between high-intensity efforts. KEY WORDS compression stockings, team sport, muscle oxygenation

Purpose: The present investigation examined the physiological and performance effects of lower-body compression garments (LBCG) during a one-hour cycling timetrial in well-trained cyclists. Methods: Twelve well-trained male cyclists ([mean ± SD] age: 20.5 ± 3.6 years; height: 177.5 ± 4.9 cm; body mass: 70.5 ± 7.5 kg; VO2max: 55.2 ± 6.8 mL·kg-1·min-1) volunteered for the study. Each subject completed two randomly ordered stepwise incremental tests and two randomly ordered one-hour time trials (1HTT) wearing either full-length SportSkins Classic LBCG or underwear briefs (control). Blood lactate concentration ([BLa-]), heart rate (HR), oxygen consumption (VO2) and muscle oxygenation (mOxy) were recorded throughout each test. Indicators of cycling endurance performance were anaerobic threshold (AnT) and VO2max values from the incremental test, and mean power (W), peak power (W), and total work (kJ) from the 1HTT. Magnitude-based inferences were used to determine if LBCG demonstrated any performance and/or physiological benefits. Results: A likely practically significant increase (86%:12%:2%; η² = 0.6) in power output at AnT was observed in the LBCG condition (CONT: 245.9 ± 55.7 W; LBCG: 259.8 ± 44.6 W). Further, a possible practically significant improvement (78%:19%:3%; η² = 0.6) was reported in muscle oxygenation economy (W·%mOxy-1) across the 1HTT (mOxy: CONT: 52.2 ± 12.2%; LBCG: 57.3 ± 8.2%). Conclusions: The present results demonstrated limited physiological benefits and no performance enhancement through wearing LBCG during a cycling time trial. [ABSTRACT FROM AUTHOR]

Concentrations of free amino acids and [K+] in human sweat can be many times higher than in plasma. Conversely, [Na+] and [Cl-] in sweat are hypotonic to plasma. It was hypothesised that the amino acids and K+ were directly or indirectly associated with the resorption of Na+ and Cl- in the sweat duct. The implication would be that, as resources of these components became limiting during prolonged exercise then the capacity to resorb [Na+] and [Cl-] would diminish, resulting in progressively higher levels in sweat. If this were the case, then [Na+] and [Cl-] in sweat would have inverse relationships with [K+] and the amino acids during exercise. Forearm sweat was collected from 11 recreational athletes at regular intervals during a prolonged period of cycling exercise after 15, 25, 35, 45, 55 and 65 minutes. The subjects also provided passive sweat samples via 15 minutes of thermal stimulation. The sweat samples were analysed for concentrations of amino acids, Na+, Cl-, K+, Mg2+ and Ca2+. The exercise sweat had a total amino acid concentration of 6.4 ± 1.2mM after 15 minutes which was lower than the passive sweat concentration at 11.6 ± 0.8mM (p<0.05) and showed an altered array of electrolytes, indicating that exercise stimulated a change in sweat composition. During the exercise period, [Na+] in sweat increased from 23.3 ± 3.0mM to 34.6 ± 2.4mM (p<0.01) over 65 minutes whilst the total concentrations of amino acids in sweat decreased from 6.4 ± 1.2mM to 3.6 ± 0.5mM. [Na+] showed significant negative correlations with the concentrations of total amino acids (r = -0.97, p<0.05), K+ (r = -0.93, p<0.05) and Ca2+ (r = -0.83, p<0.05) in sweat. The results supported the hypothesis that amino acids and K+, as well as Ca2+, were associated with resorption of Na+ and Cl-. [ABSTRACT FROM AUTHOR]