Metabolic power in hurling with respect to position and halves of match-play.

The current investigation compared the metabolic power and energetic characteristics in team sports with respect to positional lines and halves of match-play. Global positioning system (GPS) technology data were collected from 22 elite competitive hurling matches over a 3-season period. A total of 250 complete match-files were recorded with players split into positional groups of full-back; half-back; midfield; half-forward; full-forward. Raw GPS data were exported into a customized spreadsheet that provided estimations of metabolic power and speed variables across match-play events (average metabolic power [Pmet], high metabolic load distance [HMLD], total distance, relative distance, high-speed distance, maximal speed, accelerations, and deceleration). Pmet, HMLD, total, relative and high-speed distance were 8.9 ± 1.6 W·kg-1, 1457 ± 349 m, 7506 ± 1364 m, 107 ± 20 m·min-1 and 1169 ± 260 m respectively. Half-backs, midfielders and half-forwards outperformed full-backs (Effect Size [ES] = 1.03, 1.22 and 2.07 respectively), and full-forwards in Pmet (Effect Size [ES] = 1.70, 2.07 and 1.28 respectively), and HMLD (full-backs: ES = -1.23, -1.37 and -0.84 respectively, and full-forwards: ES = -1.77, -2.00 and -1.38 respectively). Half-backs (ES = -0.60), midfielders (ES = -0.81), and half-forwards (ES = -0.74) experienced a second-half temporal decrement in HMLD. The current investigation demonstrates that metabolic power may increase our understanding of the match-play demands placed on elite hurling players. Coaches may utilize these findings to construct training drills that replicate match-play demands

Practical nutritional recovery strategies for elite soccer players when limited time separates repeated matches

Specific guidelines that aim to facilitate the recovery of soccer players from the demands of training and a congested fixture schedule are lacking; especially in relation to evidence-based nutritional recommendations. The importance of repeated high level performance and injury avoidance while addressing the challenges of fixture scheduling, travel to away venues, and training commitments requires a strategic and practically feasible method of implementing specific nutritional strategies. Here we present evidence-based guidelines regarding nutritional recovery strategies within the context of soccer. An emphasis is placed on providing practically applicable guidelines for facilitation of recovery when multiple matches are played within a short period of time (i.e. 48 h). Following match-play, the restoration of liver and muscle glycogen stores (via consumption of ~1.2 gkg-1h-1 of carbohydrate) and augmentation of protein synthesis (via ~40 g of protein) should be prioritised in the first 20 minutes of recovery. Daily intakes of 6-10 gkg-1 body mass of carbohydrate are recommended when limited time separates repeated matches while daily protein intakes of >1.5 gkg-1 body mass should be targeted; possibly in the form of multiple smaller feedings (e.g., 6 x 20-40 g). At least 150% of the body mass lost during exercise should be consumed within 1 h and electrolytes added such that fluid losses are ameliorated. Strategic use of protein, leucine, creatine, polyphenols and omega-3 supplements could also offer practical means of enhancing post-match recovery. Keywords: soccer, nutrition, recovery, polyphenols, omega-3, creatine, fixture, congestio

Energy Cost of Human Locomotion on Land and in Water

Maximal absolute speeds in human locomotion range from a minimum of about 7km?h-1 in swimming (100m free style) to over 70km?h-1 in cycling (200m with a flying start), whereas the maximal muscular power of elite athletes competing in these events is essentially equal. Hence these large speed differences depend on the specific characteristics of each form of locomotion. These will be described in some detail with the aim of providing a comprehensive overview of the resulting energy cost of transport under different sets of conditions, such as constant versus accelerated or decelerated speed, uphill versus downhill slopes, the effects of barometric pressure, and of the characteristics of the terrain. The resulting overall picture can be condensed in a limited number of equations allowing us to predict overall energy expenditure as well as maximal speed in the locomotion considered, provided that a few parameters concerning the subject and the environmental conditions in question are known

Energy cost and metabolic power in elite soccer: a new match analysis approach

Purpose: Video match analysis is used for the assessment of physical performances of professional soccer players, particularly for the identification of "high intensities" considered as "high running speeds." However, accelerations are also essential elements setting metabolic loads, even when speed is low. We propose a more detailed assessment of soccer players' metabolic demands by video match analysis with the aim of also taking into account accelerations. Methods: A recent study showed that accelerated running oil a flat terrain is equivalent to running uphill at constant speed, the incline being dictated by the acceleration. Because the energy cost of-running uphill is known, this makes it possible to estimate the instantaneous energy cost of accelerated running, the corresponding instantaneous metabolic power, and the overall energy expenditure, provided that the speed (and acceleration) is known. Furthermore. the introduction of individual parameters makes it possible to customize performance profiles, especially as it concerns energy expenditure derived from anaerobic Sources. Data from 399 "Serie-A" players (mean +/- SD; age = 27 +/- 4 yr, mass = 75.8 +/- 5.0 kg, statute = 1.80 +/- 0.06 m) were collected during the 20072009 season. Results: Mean match distance was 10,950 +/- 1044 m, and average energy expenditure was 61.12 +/- 6.57 kJ.kg(-1). Total distance covered at high power (>20 W.kg(-1)) amounted to 26% and corresponding energy expenditure to approximately 42% of the total, "High intensities" expressed as high-power output are two to three times larger than those based only oil running speed. Conclusions: The present approach for the assessment of top-level soccer players match performance through video analysis allowed us to assess instantaneous metabolic power, thus redefining the concept of-high intensity" on the basis of actual metabolic power rather than on speed alone

Effects of a very congested match schedule on body-load impacts, accelerations, and running measures in youth soccer players

PURPOSE: To analyze the effects of a very congested match schedule on the total distance (TD) covered, high-intensity-running (HIR) distance, and frequency of accelerations and body-load impacts (BLIs) performed in a team of under-15 soccer players (N=10; 15.1±0.2 y, 171.8±4.7 cm, 61±6.0 kg) during an international youth competition. METHODS: Using global positioning systems, player performances were repeatedly monitored in 5 matches performed over 3 successive days. RESULTS: Significant differences were observed between matches (P<.05) for the frequency of accelerations per minute, BLIs, and BLIs per minute. No differences were observed for the TD covered, TD run per minute, number of high-intensity runs, distance covered in HIR, per-minute peak running speed attained, or frequency of accelerations. The frequency of accelerations per minute decreased across the competition while BLIs were higher during the final than in all other matches. CONCLUSIONS: These results suggest that BLIs and acceleration might be used as an alternative means to represent the external load during congested match schedules rather than measures related to running speed or distance covered

Recovery and adaptation from repeated intermittent sprint exercise

PURPOSE: This investigation aimed to 1) ascertain a detailed physiological profile of recovery from intermittent sprint exercise on athletes familiar with the exercise, and 2) investigate if athletes receive a protective effect on markers of exercise-induced muscle damage (EIMD), inflammation and oxidative stress following a repeated exposure to an identical bout of intermittent sprint exercise. METHODS: Eight well trained male team sport athletes of National League or English University Premier Division standard (mean ± SD age 23 ± 3 years; VO2max 54.8 ± 4.6 ml·kg-1·min-1) completed the Loughborough Intermittent Shuttle Test (LIST) on two occasions, separated by 14 days. Maximal isometric voluntary contraction (MIVC), counter-movement jump (CMJ), creatine kinase (CK), C-reactive protein (CRP), interleukin-6 (IL-6), F2-isoprostanes and muscle soreness (DOMS) were measured before, and up to 72 h following the initial, and repeated LIST. RESULTS: MIVC, CMJ, CK, IL-6 and DOMS all showed main effects for time (P < 0.05) following the LIST indicating EIMD was present. DOMS peaked at 24 h following LIST 1 (110±53 mm) and was attenuated following LIST 2 (56±39 mm), and was the only dependent variable to demonstrate a reduction in the second bout (P = 0.008). All other markers indicated EIMD were not different between bouts. CONCLUSION: Well-trained games players experienced EIMD following exposure to both exercise tests, despite being accustomed to the exercise type. This suggests well-trained athletes receive a very limited protective effect from the first bou