potential for wearable microtechnology devices as a means of prescribing and monitoring bowling workload. The microtechnology described typically refers to a triaxial accelerometer embedded within a global positioning satellite (GPS) unit. This unit is typically worn in a customized vest that positions the
Geoff Minett, Rob Duffield and Stephen P. Bird
To investigate the effects of an acute multinutrient supplement on game-based running performance, peak power output, anaerobic by-products, hormonal profiles, markers of muscle damage, and perceived muscular soreness before, immediately after, and 24 h following competitive rugby union games.
Twelve male rugby union players ingested either a comprehensive multinutrient supplement (SUPP), [RE-ACTIVATE:01], or a placebo (PL) for 5 d. Participants then performed a competitive rugby union game (with global positioning system tracking), with associated blood draws and vertical jump assessments pre, immediately post and 24 h following competition.
SUPP ingestion resulted in moderate to large effects for augmented 1st half very high intensity running (VHIR) mean speed (5.9 ± 0.4 vs 4.8 ± 2.3 m·min−1; d = 0.93). Further, moderate increases in 2nd half VHIR distance (137 ± 119 vs 83 ± 89 m; d = 0.73) and VHIR mean speed (5.9 ± 0.6 v 5.3 ± 1.7 m·min−1; d = 0.56) in SUPP condition were also apparent. Postgame aspartate aminotransferase (AST; 44.1 ± 11.8 vs 37.0 ± 3.2 UL; d = 1.16) and creatine kinase (CK; 882 ± 472 vs. 645 ± 123 UL; d = 0.97) measures demonstrated increased values in the SUPP condition, while AST and CK values correlated with 2nd half VHIR distance (r = −0.71 and r = −0.76 respectively). Elevated C-reactive protein (CRP) was observed postgame in both conditions; however, it was significantly blunted with SUPP (P = .05).
These findings suggest SUPP may assist in the maintenance of VHIR during rugby union games, possibly via the buffering qualities of SUPP ingredients. However, correlations between increased work completed at very high intensities and muscular degradation in SUPP conditions, may mask any anticatabolic properties of the supplement.
Ian Rollo, Lewis James, Louise Croft and Clyde Williams
The purpose of the current study was to investigate the influence of ingesting a carbohydrate-electrolyte (CHO-E) beverage ad libitum or as a prescribed volume on 10-mile run performance and gastrointestinal (GI) discomfort. Nine male recreational runners completed the 10-mile run under the following 3 conditions: no drinking (ND; 0 ml, 0 g CHO), ad libitum drinking (AD; 315 ± 123 ml, 19 ± 7 g CHO), and prescribed drinking (PD; 1,055 ± 90 ml, 64 ± 5 g CHO). During the AD and PD trials, drinks were provided on completion of Miles 2, 4, 6, and 8. Running performance, speed (km/hr), and 10-mile run time were assessed using a global positioning satellite system. The runners’ ratings of perceived exertion and GI comfort were recorded on completion of each lap of the 10-mile run. There was a significant difference (p < .10) in performance times for the 10-mile race for the ND, AD, and PD trials, which were 72:05 ± 3:36, 71:14 ± 3:35, and 72:12 ± 3.53 min:s, respectively (p = .094). Ratings of GI comfort were reduced during the PD trial in comparison with both AD and ND trials. In conclusion, runners unaccustomed to habitually drinking CHO-E beverages during training improved their 10-mile race performance with AD drinking a CHO-E beverage, in comparison with drinking a prescribed volume of the same beverage or no drinking.
Thomas Kempton, Anita C. Sirotic and Aaron J. Coutts
To examine differences in physical and technical performance profiles using a large sample of match observations drawn from successful and less-successful professional rugby league teams.
Match activity profiles were collected using global positioning satellite (GPS) technology from 29 players from a successful rugby league team during 24 games and 25 players from a less-successful team during 18 games throughout 2 separate competition seasons. Technical performance data were obtained from a commercial statistics provider. A progressive magnitude-based statistical approach was used to compare differences in physical and technical performance variables between the reference teams.
There were no clear differences in playing time, absolute and relative total distances, or low-speed running distances between successful and less-successful teams. The successful team possibly to very likely had lower higher-speed running demands and likely had fewer physical collisions than the less-successful team, although they likely to most likely demonstrated more accelerations and decelerations and likely had higher average metabolic power. The successful team very likely gained more territory in attack, very likely had more possessions, and likely committed fewer errors. In contrast, the less-successful team was likely required to attempt more tackles, most likely missed more tackles, and very likely had a lower effective tackle percentage.
In the current study, successful match performance was not contingent on higher match running outputs or more physical collisions; rather, proficiency in technical performance components better differentiated successful and less-successful teams.
Thomas W. Jones, Barry C. Shillabeer and Marco Cardinale
%–69% HR max ), third (70%–79% HR max ), fourth (80%–89% HR max ), and fifth (≥90 HR max ) intensity domains are 1, 2, 3, 4, and 5, respectively. Distances and velocities were also quantified via Polar RS800CX global positioning satellite systems (Polar Electro Oy); all training took place outdoors, and
Mário A.M. Simim, Marco Túlio de Mello, Bruno V.C. Silva, Dayane F. Rodrigues, João Paulo P. Rosa, Bruno Pena Couto and Andressa da Silva
), 527 – 533 . PubMed doi:10.1080/02640414.2014.949829 10.1080/02640414.2014.949829 Sindall , P. , Lenton , J. , Whytock , K. , Tolfrey , K. , Oyster , M.L. , Cooper , R.A. , & Goosey-Tolfrey , V. ( 2013 ). Criterion validity and accuracy of global positioning satellite and data logging
Carolina F. Wilke, Samuel P. Wanner, Weslley H.M. Santos, Eduardo M. Penna, Guilherme P. Ramos, Fabio Y. Nakamura and Rob Duffield
Positioning Satellite unit coupled with a triaxial accelerometer (SPI ProX2; GPSports Systems, Melbourne, Australia) and a compatible heart rate receiver (Polar, Kempele, Finland). The magnitude of impact values should be analyzed with caution, as this accelerometer has been shown to underestimate