Oidui Usabiaga

Number of Players and Relative Pitch Area per Player: Comparing Their Influence on Heart Rate and Physical Demands in Under-12 and Under-13 Football Players.

The aim of the present study is to analyse the influence of different large-sided games (LSGs) on the physical and physiological variables in under-12s (U12) and -13s (U13) soccer players. The effects of the combination of different number of players per team, 7, 9, and 11 (P7, P9, and P11, respectively) with three relative pitch areas, 100, 200, and 300 m2 (A100, A200, and A300, respectively), were analysed in this study. The variables analysed were: 1) global indicator such as total distance (TD); work:rest ratio (W:R); player-load (PL) and maximal speed (Vmax); 2) heart rate (HR) mean and time spent in different intensity zones of HR (<75%, 75–84%, 84–90% and >90%), and; 3) five absolute (<8, 8–13, 13–16 and >16 Km h-1) and three relative speed categories (<40%, 40–60% and >60% Vmax). The results support the theory that a change in format (player number and pitch dimensions) affects no similarly in the two players categories. Although it can seem that U13 players are more demanded in this kind of LSG, when the work load is assessed from a relative point of view, great pitch dimensions and/or high number of player per team are involved in the training task to the U12 players. The results of this study could alert to the coaches to avoid some types of LSGs for the U12 players such as: P11 played in A100, A200 or A300, P9 played in A200 or A300 and P7 played in A300 due to that U13>U12 in several physical and physiological variables (W:R, time spent in 84–90%HRmax, distance in 8–13 and 13–16 Km h-1 and time spent in 40–60%Vmax). These results may help youth soccer coaches to plan the progressive introduction of LSGs so that task demands are adapted to the physiological and physical development of participants.

Effects of different surfaces in time-motion characteristics in youth elite tennis players

The aim of this study was to compare the physical profile between clay and hard court in match-play for high-level young tennis players using GPS technology. 4 female and 10 male high-level young Spanish tennis players (under 12 years n=28 and under 14 years n=28 records) took part in the study (age 12.9 ±1.3 years). Eleven portable GPS devices (MinimaxXv.4.0, Catapult Innovations) operating at a sampling frequency of 10 Hz were used to collect data. Physical demands were assessed over 42 tennis matches, with individual players being tracked in 2 matches on hard and 2 matches on clay court (4 matches by player) totalling 56 individual recordings on two surfaces: CLAY court (n=28) and HARD court (n=28). The results showed significant differences between surfaces (HARD>CLAY) in acceleration distance covered (DCAm) HARD= 42.4±5.7 vs. CLAY= 31.6±8.9 in m·min-1; F(3, 56)= 20.6; p= < 0.001; η2 p= 0.30; ES=0.59), average speed (HARD= 3.2±0.4 vs. CLAY= 2.8±0.6 in m·s-1; F(3, 56)= 3.7; p= 0.061; η2 p =0.07; ES=0.48) and maximum speed (HARD= 4.6±0.6 vs. CLAY= 4.0±0.7 in m·s-1; F(3, 56)= 5.9; p= 0.019; η2 p= 0.11; ES=0.60). The main conclusion of this study was the hard court games were characterized by high intensity efforts. Tennis players who played matches on hard court covered a greater distance accelerating, with more pacing and higher speeds. The data suggests that coaches should adapt the training strategy to the type of surface on which the players will play their next tournament, in order to improve performance and/or propose protocols to prevent injuries.

The Influence of Scoring Targets and Outer-Floaters on Attacking and Defending Team Dispersion, Shape and Creation of Space During Small-Sided Soccer Games

Abstract The effect of altered game formats on team performances during soccer practice can be harnessed by coaches to stimulate specific tactical behaviours. The aim of the present study was to analyse the influence of using (i) small goals [SG], (ii) goalkeepers [7G] and (iii) floaters [7GF] on the dispersion, shape and available space of teams during small-sided games (SSGs). Twenty-four male soccer players were distributed into four teams composed of five players, two goalkeepers and two floaters that performed six SSG bouts of 6 min, interspersed with 6 min of passive recovery. Offensive and defensive phases were also analysed separately in order to verify the preservation of basic principles of attacking (teams more stretched to create free space) and defending (teams more compact to tie-up space) during SSGs. The variables used to characterize the collective behaviour were: length [L], width [W], team shape [Sh], and team separateness [TS]. Results revealed that the teams showed different collective behaviours depending on SSG format and a playing phase: a) L and W were higher in attack than in defence in all SSGs; b) team shapes were more elongated in defence in all SSGs except SG; c) the space separating players from their closest opponents (TS) was shorter in 7G; and d) SG and 7GF elicited greater defensive openness due to increased team width. The results suggest that manipulating task constraints, such as goal size, presence or absence of goalkeepers and floaters can be harnessed by coaches to shape distinct team tactical behaviours in SSGs while preserving the basic principles of attacking and defending.

New variables and new agreements between 10 Hz global positioning system devices in tennis drills

The knowledge about physical demands in different sports has increased, thanks to the application of global positioning system devices. The reliability and validity of 10 Hz global positioning system devices have been assessed by some authors. The majority of the studies only addressed the reliability of the devices or, in other words, the ability of scores of global positioning system device to differentiate among subjects or objects. The reliability is based on correlations (such as the intraclass correlation coefficient) which do not give the researcher information that can be interpreted in a practical way. In this way, the aim of this study was to assess the grade of agreement among repeated measurements made on the same subject using two global positioning system devices simultaneously. Four trained male tennis players participated in the study. The participants completed tennis-simulated point-games (n = 32), each player wearing two devices at the same time. Global indicators, such as Player Load (PL), Exertion Index (EI) and Equivalent Distance Index (EDI) per minute, were monitored through the use of global positioning system devices (MinimaxX v4.0; Catapult Innovations, Melbourne, Australia) operating at the above-mentioned sampling frequency of 10 Hz. The systematic error is that there is tendency of the global positioning system devices to measure systematically different from others Vmean (−1.03 m · min−1), Vpeak (−10.31 m · min−1), Equivalent Distance Index (0.63 ratio), PLmin (0.35 UA min−1) and EImin (−0.01) variables. As for random error (limit of agreement), we would expect that in PLmin, the global positioning systems would differ in 95% of the cases between 2.12 and −1.42 m · min−1; any value out of the limits of agreement would result relevant for the practical point of view. We concluded that the global positioning system devices produce systematically different results from one another; therefore, the bias from one global positioning system to another should be subtracted to compare the results between the global positioning systems.

Differences between running activity in tennis training and match-play

ABSTRACT The aim of this study was to compare the running activity between training and match-play for young high-level tennis players. Ten female and ten male young high-level tennis players took part in the study (13.80 age ±2.08 years). Twelve Portable GPS devices operating at10 Hz were used to collect velocity data. Match-play analysis was carried out by Aragon Tennis Master on hard court and training analysis was carried out by High Level Performance Centre of the Aragon Tennis Federation. The distance covered per minute (DCmin) by players in match-play was higher than in training (Match-play = 50.4 ± 6.0 m· min−1 vs. Training = 34.5 ± 6.2 m· min−1; F(1, 76) = 163.9; p < 0.001; ὴ2p = 0.64, moderate effect). The acceleration distance covered per minute (DCAmin), was higher in match-play than in training (Match-play = 45.0 ± 3.0 m· min−1 vs. Training = 28.6 ± 6.2 m· min−1; F(1, 76) = 267.6; p < 0.001; ὴ2p = 0.7, moderate effect). The results showed that match-play was characterised by demanding to players a great number of accelerating efforts, whereas in training, players do not replicate these actions, predominating movements at high average speed than in match-play.

More acceleration and less speed to assess physical demands in female young tennis players

Abstract The aim of this study was to describe the physical demands in match of female young tennis players, focusing on velocity and acceleration using microtechnology. Twenty-six female high-level young tennis players participated in the current study. Match-play played in official Tournament was codified using a global positioning system (10 Hz) that includes accelerometry (100 Hz). The results showed that: (1) the Estimation Distance (59.1 ± 24.8 m min−1) was overcome in 33% to the Real Distance (44.4 ± 7.7 m min−1); (2) the Acceleration Distance was around 89% of the Real Distance; (3) the 97.0 ± 6.1% of time and 90.9 ± 8.2% of distance covered by players were obtained in low speed zones (Positioning: 0–0.5 m s−1 and Jogging: 0.6–1.9 m s−1, respectively). The main conclusion of this study was that the two dimensions, velocity and acceleration, allowed to obtain complementary values of physical demands of tennis players. Nevertheless, acceleration dimension could give us more information about the intermittent profile of tennis players who are not able to reach high speeds. Therefore, tennis coaches should take into account the demands in both dimensions, specifically in acceleration/deceleration variables to design specific training tasks.

A time motion analysis of lead climbing in the 2012 men’s and women’s world championship finals

The dearth of research in lead rock climbing means that much remains to be learnt about the external and internal demands of this sport and about the suitability of current training protocols and techniques. The aim of this study was to perform a time motion analysis of movements made by elite lead climbers and to compare results between men and women. Video recordings of the men’s and women’s lead finals in the 2012 Sport Climbing World Championships were analyzed. Sixteen ascents (8 by men and 8 by women) were coded using the purpose-designed Sport Climbing Observational Tool (SCOT), with recording of climbing speed and frequency and duration of use of handholds, successful and failed quickdraw clipping actions, chalk use, and rest gestures. The mean ± SD time needed to complete the climbing route was 220 ± 81.7 s for men and 355.9 ± 92.8 s for women. Significant differences were also found for the frequency and duration of holds, chalk use, and rest gestures, which were all greater in women. The findings of this study demonstrate how results from time motion analysis of competitive rock climbing, combined with evaluation of responses during intermittent isometric exercise, could be used to design targeted training exercises and tests for lead climbers.