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Plews D.J.,High Performance Sport New Zealand | Laursen P.B.,High Performance Sport New Zealand | Kilding A.E.,Auckland University of Technology | Buchheit M.,ASPIRE Academy for Sports Excellence
International Journal of Sports Physiology and Performance | Year: 2013

The aim of this study was to compare 2 different methodological assessments when analyzing the relationship between performance and heart-rate (HR)-derived indices (resting HR [RHR] and HR variability [HRV]) to evaluate positive adaptation to training. The relative change in estimated maximum aerobic speed (MAS) and 10-km-running performance was correlated to the relative change in RHR and the natural logarithm of the square root of the mean sum of the squared differences between R-R intervals on an isolated day (RHRday; Ln rMSSDday) or when averaged over 1 wk (RHRweek; Ln rMSSDweek) in 10 runners who responded to a 9-wk training intervention. Moderate and small correlations existed between changes in MAS and 10-km-running performance and RHRday (r = .35, 90%CI [-.35, .76] and r = -.21 [-.68, .39]), compared with large and very large correlations for RHRweek (r = -.62 [-.87, -.11] and r = .73 [.30, .91]). While a trivial correlation was observed for MAS vs Ln rMSSDday (r = -.06 [-.59, .51]), a very large correlation existed with Ln rMSSDweek (r = .72 [.28, .91]). Similarly, changes in 10-km-running performance revealed a small correlation with Ln rMSSDday (r = -.17 [-.66, .42]), vs a very large correlation for Ln rMSSDweek (r = -.76 [-.92, -.36]). In conclusion, the averaging of RHR and HRV values over a 1-wk period appears to be a superior method for evaluating positive adaption to training compared with assessing its value on a single isolated day. © 2013 Human Kinetics, Inc.

Nybo L.,Copenhagen University | Girard O.,Research and Education Center | Mohr M.,Copenhagen University | Mohr M.,University of Exeter | And 3 more authors.
Medicine and Science in Sports and Exercise | Year: 2013

Purpose: This study aimed to determine whether competitive intermittent exercise in the heat affects recovery, aggravates markers of muscle fiber damage, and delays the recovery of performance and muscle glycogen stores. Methods: Plasma creatine kinase, serum myoglobin, muscle glycogen, and performance parameters (sprint, endurance, and neuromuscular testing) were evaluated in 17 semiprofessional soccer players before, immediately after, and during 48 h of recovery from a match played in 43 C (HOT) and compared with a control match (21 C with similar turf and setup). Results: Muscle temperature was ∼1 C higher (P < 0.001) after the game in HOT compared with control and reached individual values between 39.9 C and 41.1 C. Serum myoglobin levels increased by more than threefold after the matches (P < 0.01), but values were not different in HOT compared with control, and they were similar to baseline values after 24 h of recovery. Creatine kinase was significantly elevated both immediately and 24 h after the matches, but the response after HOT was reduced compared with control. Muscle glycogen responses were similar across trials and remained depressed for more than 48 h after both matches. Sprint performance and voluntary muscle activation were impaired to a similar extent after the matches (sprint by ∼2% and voluntary activation by ∼1.5%; P < 0.05). Both of these performance parameters as well as intermittent endurance capacity (estimated by a Yo-Yo IR1 test) were fully recovered 48 h after both matches. CONCLUSION: Environmental heat stress does not aggravate the recovery response from competitive intermittent exercise associated with elevated muscle temperatures and markers of muscle damage, delayed resynthesis of muscle glycogen, and impaired postmatch performance. Copyright © 2013 by the American College of Sports Medicine.

Buchheit M.,ASPIRE Academy for Sports Excellence | Rabbani A.,Islamic Azad University at Najafabad
International Journal of Sports Physiology and Performance | Year: 2014

The aim of the current study was to examine the relationship between performance of the Yo-Yo Intermittent Recovery Test Level 1 (Yo-YoIR1) and the 30-15 Intermittent Fitness Test (30-15IFT) and to compare the sensitivity of both tests to training. Fourteen young soccer players performed both tests before and after an 8-wk training intervention, which included 6 sessions/wk: 2 resistance training sessions, 2 high-intensity interval training sessions after technical training (4 sets of 3:30 min of generic running and small-sided games [4v4] during the first and second 4-wk periods, respectively [90-95% maximal HR], interspersed with 3 min at 60-70% maximal HR), and 2 tactical-only training sessions. There was a large correlation between 30-15IFT and Yo-YoIR1 (r = .75, 90% confidence limits [CL] 0.57;0.86). While within-test percentage changes suggested a greater sensitivity to training for the Yo-YoIR1 (+35%, 90%CL 24;45) than for the 30-15IFT (+7%; 4;10), these changes were similarly rated as almost certain (with chances for greater/similar/lower values after training of 100/0/0 for both tests) and moderate, ie, standardized difference, ES = +1.2 90%CL (0.9;1.5) for Yo-YoIR1 and ES = +1.1 (0.7;1.5) for 30-15IFT. The difference in the change between the 2 tests was clearly trivial (0/100/0, ES = -0.1, 90%CL -0.1;-0.1). Both tests might evaluate slightly different physical capacities, but their sensitivity to training is almost certainly similar. These results also highlight the importance of using standardized differences instead of percentage changes in performance to assess the actual training effect of an intervention. © 2014 Human Kinetics, Inc.

Hill R.,HP Sports and YSC Sports | Simpson B.,ASPIRE Academy for Sports Excellence | Manning J.,University of Swansea | Kilduff L.,University of Swansea
Journal of Sports Sciences | Year: 2012

A low digit ratio (2D:4D) and low 2D: 4D in the right compared with the left hand (right-left 2D:4D) are thought to be determined by high in utero concentrations of testosterone, and are related to ''masculine'' traits such as aggression and performance in sports like running and rugby. Low right-left 2D:4D is also related to sensitivity to testosterone as measured by the number of cytosine-adenine-guanine triplet repeats in exon 1 of the androgen receptor gene. Here we show that low right-left 2D:4D is associated with high maximal oxygen uptake (VO 2max), high velocity at VO 2max, and high maximum lactate concentration in a sample of teenage boys. We suggest that low right-left 2D:4D is linked to performance in some sports because it is a proxy of high sensitivity to prenatal and maybe also circulating testosterone and high VO 2max. © 2012 Taylor & Francis.

Fernandez-Fernandez J.,University Miguel Hernandez | Boullosa D.A.,Catholic University of Brasilia | Sanz-Rivas D.,Coaches Education | Filaire E.,University of Orleans | Mendez-Villanueva A.,ASPIRE Academy for Sports Excellence
International Journal of Sports Medicine | Year: 2015

This study sought to compare the psychophysiological stress responses during an actual competitive game and a training session in a group of high-level young female tennis players. 12 players were monitored during one match and a training day (i. e., simulated match play). Measurements included salivary cortisol (SC), the revised Competitive Sport Anxiety Inventory, heart rate (HR), and rate of perceived exertion (RPE). Match day elicited higher SC levels for losers at all points in time when compared to winners. All players showed significantly lower SC levels during training when compared to the match at all points in time except during the evening for winners. Winners of match and training situations had significantly higher self-confidence and lower cognitive anxiety and somatic anxiety scores than losers. Heart rate and RPE were significantly higher for losers only during the match (158.9 ± 8.3 vs. 168 ± 6.7 bpm; 12.9 ± 1.2 vs. 15 ± 0.8, for losers and winners, respectively). There were moderate to strong correlations between SC, self-confidence and anxiety scores, and match workload (i. e., HR and RPE) only during the match day. These results indicate that the interplay between psychophysiological responses, match workload and outcome was evident only under real competitive situations. © Georg Thieme Verlag KG.

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