Effects of tapering on physical match activities in professional soccer players     

Mohamed Saifeddin Fessi  Nidhal Zarrouk  Valter Di Salvo  Cristoforo Filetti  Alan R. Barker 《Journal of sports sciences》2016,34(24):2189-2194

ABSTRACT

This study aimed to examine: (i) the effect of decreasing training load (TL) during taper weeks on physical match activities in professional soccer players, and (ii) to disclose the relationship between weekly TL and physical match activities. Rating of perceived exertion was collected after each training session and match to quantify the TL in 19 professional players over 17 standard and 7 taper weeks during the season. Physical match activities were quantified by a computerised match analysis system and compared between standard training and taper weeks. Compared to standard weeks, the duration and frequency of training sessions during the taper weeks decreased (?21.7% and ?18.8%, respectively; P < 0.01) with no change in intensity (?4.8%; P = 0.09). Consequently, the weekly TL decreased during the taper weeks (?25.5%; P < 0.01). Increases in distance covered by intense running (+15.1%; P < 0.05), high-intensity running (HIR) (+15.7%; P < 0.01), number of sprints (+17.8%; P < 0.05) and number of high-speed runs (+15.7%; P < 0.05) were observed during the seven matches played after the taper weeks. High relationships were observed between TL and HIR distance covered, number of HIR and number of sprints (r = ?0.53; r = ?0.55; r = ?0.65, respectively; P < 0.01). Decreasing TL during taper weeks by reducing training duration and frequency but maintaining intensity was associated with an increase in physical activities during matches. However, it needs to be determined whether tapering or other match factors led to the changes in match activity.  相似文献   

Physiological responses to ball-drills in regional level male basketball players     

Castagna C  Impellizzeri FM  Chaouachi A  Ben Abdelkrim N  Manzi V 《Journal of sports sciences》2011,29(12):1329-1336

The main aim of this study was to assess the physiological responses of male basketball players during usual basketball ball-drills. Fourteen male basketball players (age 18.9 ± 2.3 years) performed the following full-court (28 × 15 m) basketball ball-drills (3 × 4-min with 3-min passive rest): five-a-side (5v5), three-a-side (3v3) and two-a-side (2v2). A main effect (P < 0.0001) for ball-drills modes was evident for all variables (5v5 < 3v3 < 2v2). Mean [Vdot]O(2) during the 5v5, 3v3 and 2v2 were 39.0 ± 7.2, 42.0 ± 7.5 and 45.0 ± 6.5 ml · kg(-1) · min(-1) (69 ± 11, 74 ± 12 and 79 ± 11% of [Vdot]O(2peak)) respectively (5v5 = 3v3 < 2v2, P < 0.001). Mean blood-lactate concentrations for 5v5, 3v3 and 2v2 were 4.2 ± 1.8, 6.2 ± 2.3 and 7.8 ± 1.2 mmol (l(-1) respectively (5v5 < 3v3 < 2v2, P < 0.01). During the 5v5, 3v3 and 2v2 mean heart-rate (HR) was 84.0 ± 9.2, 88.0 ± 8.4 and 92.0 ± 5.6% of the individual peak respectively (5v5 < 3v3 < 2v2; P < 0.001). No significant differences were found between the regression-line slope (P = 0.86) and intercept (P = 0.45) of the HR-[Vdot]O(2) relationships of the multistage maximal fitness test (r(2) from 0.80 to 0.96, P < 0.001) and ball-drills (r(2) from 0.70 to 0.95, P < 0.001) conditions. Reducing the number of players over the same playing court resulted in increments in physiological demands. The 2v2 condition provided responses in the range of those reported to improve aerobic and anaerobic fitness. The aerobic demands of ball-drills can be accurately assessed using heart-rate monitoring in basketball.  相似文献   

Science, religion, and the quest for knowledge and truth: an Islamic perspective     

Nidhal Guessoum 《Cultural Studies of Science Education》2010,5(1):55-69

This article consists of two parts. The first one is to a large extent a commentary on John R. Staver’s “Skepticism, truth as coherence, and constructivist epistemology: grounds for resolving the discord between science and religion?” The second part is a related overview of Islam’s philosophy of knowledge and, to a certain degree, science. In responding to Staver’s thesis, I rely strongly on my scientific education and habit of mind; I also partly found my views on my Islamic background, though I enlarge my scope to consider western philosophical perspectives as well. I differ with Staver in his definition of the nature, scope, and goals of religion (concisely, “explaining the world and how it works”), and I think this is the crux of the matter in attempting to resolve the perceived “discord” between science and religion. The heart of the problem is in the definition of the domains of action of science and religion, and I address this issue at some length, both generically and using Islamic principles, which are found to be very widely applicable. The concept of “reality,” so important to Staver’s thesis, is also critically reviewed. The philosophy of knowledge (and of science) in Islam is briefly reviewed in the aim of showing the great potential for harmony between the two “institutions” (religion and science), on the basis of the following philosophy: science describes nature, whereas religion gives us not only a philosophy of existence but also an interpretative cloak for the discoveries of science and for the meaning of the cosmos and nature. I conclude by insisting that though science and religion can be considered as two worldviews that propose to describe “reality” and to explain our existence and that of the world; they may come to compete for humans’ minds and appear to enter into a conflicting position, but only if and when we confuse their domains and modes of action.   相似文献   

Kinematic analysis of the shot-put: A method of assessing the mechanical work of the hand action force     

Mounir Landolsi  Lazhar Labiadh  Fayçal Zarrouk  Khaled Maaref  Slaheddine Ghannouchi  Zouhair Tabka 《European Journal of Sport Science》2018,18(9):1208-1216

The aims of this study were to (1) propose a method for evaluating shot-putters mechanical power, (2) investigate the relationship between mechanical work of hand action force (W_HAF), peak power output (PPO) of different limbs and shot-put performance and (3) show which of these two parameters (W_HAF, PPO) were the most appropriate to characterize the explosive abilities of the shot-putter. Twelve junior right-handed shot-putters, practised glide technique shot-put throwers (personal best?=?13.57 ± 1.72 m), participated in this study. Arm and leg force-velocity tests were performed to measure PPO. Kinematic analysis was conducted during a shot-putting event in regular conditions to quantify the W_HAF at the release moment and shot-put performance. Significant correlations were found between absolute arm and leg PPO with upper and lower muscle volumes (r?=?.67; p?=?.03; r?=?.76; p?=?.01; r?=?.74, p?=?.01; r?=?.65, p?=?.04). Positive relationships were recorded between absolute arm and leg PPO and shot-put performance (r?=?.67, p?=?.02; r?=?.81, p?=?.004, respectively). Shot-put performance was also closely related to the W_HAF (r?=?.93, p?=?.0001) and release velocity parameter (r?=?.86, p?=?.001). The present results confirm that force-velocity test and W_HAF constitute useful tools for assessing mechanical power in throwing. The W_HAF could be considered as more suitable than force-velocity test.  相似文献