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1.
Biol Sport ; 37(1): 49-57, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32205910

RESUMEN

To compare the pop-up and counter movement jump (CMJ) and to analyse the relationships among the variables between sexes and different ages [under (U16), over (O16) 16 years] in male and female competitive surfers. Eighty-three surfers were divided according to sex, male (n = 55) and female (n = 28), and to age, U16 (n = 47) and O16 (n = 36). Vertical jump and pop-up movements were measured through the vertical ground reaction force with a force plate. CMJ demonstrated that the O16 male group exhibited significantly greater force compared to females in the concentric phase of the jump (CMJFMAX) (p < 0.01, ES = 1.82, large). Female U16 and O16 groups presented increased unloading rates in the eccentric phase compared to male surfers (CMJULR) (p < 0.05, ES = 0.73, moderate and p < 0.05, ES = 0.12, trivial, respectively). O16 males obtained significantly greater values than O16 females in the push-up phase (POPPUSH) (p < 0.05, ES = 0.76, moderate). Moderate correlations were found between lower-body power capacity and the pop-up (r = 0.32; ± 0.16 CL, p < 0.01, 98.1/1.9/0, very likely, moderate). General and skill-specific strengths are different in competitive male and female surfers, dependent upon their age range. The moderate association between CMJ and pop-up suggests that the pop-up might be influenced by other factors such as coordination or upper-body strength. Therefore, competitive surfers should also train the upper body strength and overall coordination in order to improve the performance of the pop-up movement.

2.
Res Sports Med ; 27(3): 283-297, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30343591

RESUMEN

The aims of this study were to compare the external and internal match responses and fitness performance of national field referees (FRs) and assistant referees (ARs), and to examine the relationships between these fitness measures and physical and physiological responses during match play. Forty-four national soccer match officials (e.g. FRs and ARs) participated in this study. The distance covered and the VO2max in Yo-Yo Intermittent recovery test (YYIR1) and the 30 m sprint test correlated with high speed and high intensity activities during match play in FRs (r = -0.48-0.63, moderate to large, very likely to most likely, p < 0.05). In addition, YYIR1 performance was related to high accelerations (r = 0.41, moderate, likely, p < 0.05) and high decelerations (r = 0.44, moderate, very likely, p < 0.05) for FRs. Better sprint and cardiovascular fitness could be relevant to the performance of FRs during match play.


Asunto(s)
Rendimiento Atlético/fisiología , Capacidad Cardiovascular , Fútbol/fisiología , Aceleración , Adulto , Desaceleración , Prueba de Esfuerzo , Humanos , Consumo de Oxígeno , Carrera/fisiología , Adulto Joven
3.
J Strength Cond Res ; 32(5): 1329-1335, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-28475553

RESUMEN

Fernández-Gamboa, I, Yanci, J, Granados, C, Freemyer, B, and Cámara, J. Competition load described by objective and subjective methods during a surfing championship. J Strength Cond Res 32(5): 1329-1335, 2018-The aims of this study were to describe the competition load of surfers during a single heat through objective and subjective methods and to analyze the relationship between objective and subjective methods with the judges' score. Ten competitive surfers were fitted with a global positioning system (GPS) during a competitive heat. The GPS was synchronized with a chronometer and a stationary video camera to identify the surfer's specific actions. After the end of each heat, participants were assessed for the rating of perceived respiratory and muscular exertion (RPEres, RPEmus), and also, official scores from every participant were collected. A very large significant relationship between wave-riding distance and respiratory perceived exertion heat load (RPEres HL, r = 0.79; ±0.26 confidence limit [CL], p < 0.01, 99.5/0.4/0.1, very likely) was found. Active time was also very large and significantly related to both RPEres HL (r = 0.75; ±0.29 CL, p < 0.05, 99.0/0.8/0.2, very likely) and muscular perceived exertion heat load (RPEmus HL, r = 0.83; ±0.22 CL, p < 0.01, 99.8/0.2/0.0, most likely). Very large significant correlation was obtained between the RPEres and score (r = 0.83; ±0.22 CL, p < 0.01, 99.8/0.2/0.0, most likely). The subjective method seems to be a good instrument to assess the HL of a surf competition. Wave characteristics seem to be an important factor in perceived exertion during competitive surfing.


Asunto(s)
Percepción , Esfuerzo Físico/fisiología , Deportes/fisiología , Adulto , Sistemas de Información Geográfica , Humanos , Masculino , Reproducibilidad de los Resultados , Grabación en Video
4.
J Strength Cond Res ; 32(6): 1715-1722, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29786628

RESUMEN

Castillo, D, Castagna, C, Cámara, J, Iturricastillo, A, and Yanci, J. Influence of team's rank on soccer referees' external and internal match loads during official matches. J Strength Cond Res 32(6): 1715-1722, 2018-The aim was to examine the external and the internal match loads (ML) of field referees (FRs) attending teams of different ranking during championship matches. Twenty FR who officiated in 30 official soccer matches (30 observations) participated in our study. The criteria for allocating the soccer referees' ML results were based on the teams' final league positions as follows: matches performed by Top 10 teams (TOP10), matches performed by bottom 10 teams (BOT10), and matches played among TOP10 and BOT10 teams (MIXED). External (match activities, accelerations [Acc], and decelerations [Dec]) and internal MLs (Edwards' heart rate [HR]-derived training impulse [TRIMPEDW], HRmean expressed as a percentage of HRpeak [%HRpeak], and differentiated rating of perceived exertion [dRPE]) were recorded. The main results showed that FR, who officiated TOP10 matches, covered more distance at a low walking speed (<3.6 km·h) and performed a higher percentage of high-intensity accelerations and decelerations than those FR who officiated lower ranked teams' matches. Moreover, FR who officiated MIXED matches registered lower values of TRIMPEDW MLs and %HRpeak and declared higher respiratory (sRPEres ML) and muscular (sRPEmus ML) perceived MLs during the second half. Considering those FR who officiate matches between teams of a higher competitive level will need to produce higher match responses, especially regarding the percentage of distance covered at high intensity, accelerations, and decelerations; physical trainers of soccer referees at a high competitive level should implement these high-intensity short-term actions in specific training regimes.


Asunto(s)
Juicio , Carrera/fisiología , Fútbol/fisiología , Aceleración , Adulto , Desaceleración , Frecuencia Cardíaca , Humanos , Masculino , Frecuencia Respiratoria/fisiología
5.
J Sports Sci ; 35(14): 1396-1401, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27476326

RESUMEN

In cycling, it is common practice to have a break in the off season longer than 4 weeks while adopting an almost sedentary lifestyle, and such a break is considered to be long-term detraining. No previous studies have assessed the effect of training cessation with highly trained young cyclists. The purpose of the present investigation was to examine effects of 5 weeks of training cessation in 10 young (20.1 ± 1.4 years) male road cyclists for body composition, haematological and physiological parameters. After training cessation, body mass of cyclists increased (P = 0.014; ES = 0.9). [Formula: see text] (L · min-1 = -8.8 ± 5.0%, mL · kg-1·min-1 = -10.8 ± 4.2%,), Wmax (W = -6.5 ± 3.1%, W · kg-1 = -8.5 ± 3.3%,), WLT1 (W = -12.9 ± 7.0%, W · kg-1 = -14.8 ± 7.4%,), WLT2 (W = -11.5 ± 7.0%, W · kg-1 = -13.4 ± 7.6%,) and haematological (red blood cells count, -6.6 ± 4.8%; haemoglobin, -5.4 ± 4.3% and haematocrit, -2.9 ± 3.0%) values decreased (P ≤ 0.028; ES ≥ 0.9). Five weeks of training cessation resulted in large decreases in physiological and haematological values in young top-level road cyclists suggesting the need for a shorter training stoppage. This long-term detraining is more pronounced when expressed relative to body mass emphasising the influence of such body mass on power output. A maintenance programme based on reduced training strategies should be implemented to avoid large declines in physiological values in young cyclists who aspire to become professionals.


Asunto(s)
Ciclismo/fisiología , Acondicionamiento Físico Humano , Composición Corporal , Índice de Masa Corporal , Recuento de Eritrocitos , Hematócrito , Hemoglobinometría , Humanos , Ácido Láctico/sangre , Masculino , Consumo de Oxígeno/fisiología , Conducta Sedentaria , Factores de Tiempo , Adulto Joven
6.
J Strength Cond Res ; 31(8): 2231-2237, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-27398919

RESUMEN

Fernandez-Gamboa, I, Yanci, J, Granados, C, and Camara, J. Comparison of anthropometry and lower limb power qualities according to different levels and ranking position of competitive surfers. J Strength Cond Res 31(8): 2231-2237, 2017-The aim of this study was to compare competitive surfers' lower limb power output depending on their competitive level, and to evaluate the association between competition rankings. Twenty competitive surfers were divided according to the competitive level as follows: international (INT) or national (NAT), and competitive ranking (RANK1-50 or RANK51-100). Vertical jump and maximal peak power of the lower limbs were measured. No differences were found between INT and NAT surfers in the anthropometric variables, in the vertical jump, or in lower extremity power; although the NAT group had higher levels on the elasticity index, squat jumps (SJs), and counter movement jumps (CMJs) compared with the INT group. The RANK1-50 group had a lower biceps skinfold (p < 0.01), lower skinfolds in the legs (Front thigh: p ≤ 0.05; medial calf: p < 0.01), lower sum of skinfolds (p ≤ 0.05), higher SJ (p < 0.01), CMJ (p < 0.01), and 15 seconds vertical CMJ (p ≤ 0.05); also, maximal peak power of the right leg (MPPR) and left leg (MPPL) were higher in the RANK1-50 group. Moderate to large significant correlations were obtained between the surfers' ranking position and some skinfolds, the sum of skinfolds, and vertical jump. Results demonstrate that surfers' physical performance seems to be an accurate indicator of ranking positioning, also revealing that vertical jump capacity and anthropometric variables play an important role in their competitive performance, which may be important when considering their power training.


Asunto(s)
Atletas , Extremidad Inferior/fisiología , Fuerza Muscular/fisiología , Músculo Esquelético/fisiología , Deportes/fisiología , Adolescente , Adulto , Antropometría , Brazo/fisiología , Humanos , Masculino , Movimiento/fisiología , Muslo/fisiología , Adulto Joven
7.
J Strength Cond Res ; 31(8): 2169-2175, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28731978

RESUMEN

Gómez-Molina, J, Ogueta-Alday, A, Stickley, C, Tobalina, JC, Cabrejas-Ugartondo, J, and García-López, J. Differences in spatiotemporal parameters between trained runners and untrained participants. J Strength Cond Res 31(8): 2169-2175, 2017-The aim of this study was to compare the spatiotemporal parameters of trained runners and untrained participants with the same foot strike pattern (rearfoot) during running at controlled speeds. Twenty-one participants were classified in 2 groups according to their training experience: Trained (n = 10, amateur runners with long distance training experience) and Untrained (n = 11, healthy untrained participants). Anthropometric variables were recorded, and the participants performed both a submaximal (between 9 and 15 km·h) and a graded exercise running test (from 6 km·h until exhaustion) on a treadmill. Physiological (V[Combining Dot Above]O2max, heart rate, running economy [RE], peak speed …) and biomechanical variables (contact and flight times, step rate, and length) were simultaneously registered. Trained runners showed higher step rate and shorter step length than the Untrained group at the same running speeds (between 4 and 7%, p ≤ 0.05) and at the same physiological intensities (between 7 and 11%, p ≤ 0.05). However, there were no differences in contact and flight times between groups. Significant differences (p ≤ 0.05) and large effect sizes (Cohen's d) between groups were found for body mass, sum of 6 skinfolds, V[Combining Dot Above]O2max, peak speed, and ventilatory threshold and respiratory compensation threshold speeds. The Trained group also showed a ∼7% better RE (ml·kg·km) than the Untrained group. In conclusion, adopting higher step rate and shorter step length may be an adaptive mechanism of the Trained group to reduce injury risk and possibly improve RE. However, contact and flight times were consistent regardless of training level.


Asunto(s)
Atletas , Carrera/fisiología , Adulto , Antropometría , Fenómenos Biomecánicos , Fatiga/fisiopatología , Pie/fisiología , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Consumo de Oxígeno/fisiología , Factores de Tiempo
8.
J Sports Sci Med ; 16(2): 187-194, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28630571

RESUMEN

The aims of this study were to establish and validate various predictive equations of half-marathon performance. Seventy-eight half-marathon male runners participated in two different phases. Phase 1 (n = 48) was used to establish the equations for estimating half-marathon performance, and Phase 2 (n = 30) to validate these equations. Apart from half-marathon performance, training-related and anthropometric variables were recorded, and an incremental test on a treadmill was performed, in which physiological (VO2max, speed at the anaerobic threshold, peak speed) and biomechanical variables (contact and flight times, step length and step rate) were registered. In Phase 1, half-marathon performance could be predicted to 90.3% by variables related to training and anthropometry (Equation 1), 94.9% by physiological variables (Equation 2), 93.7% by biomechanical parameters (Equation 3) and 96.2% by a general equation (Equation 4). Using these equations, in Phase 2 the predicted time was significantly correlated with performance (r = 0.78, 0.92, 0.90 and 0.95, respectively). The proposed equations and their validation showed a high prediction of half-marathon performance in long distance male runners, considered from different approaches. Furthermore, they improved the prediction performance of previous studies, which makes them a highly practical application in the field of training and performance.

9.
J Sports Sci ; 34(6): 557-63, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26523630

RESUMEN

The aim of this study was to quantify the acute impact of soccer match officiating on selected physiological and physical performance measures. Twenty-four officials from the Spanish National 3rd Division participated in this study. External global positioning system and internal (heart rate) load data were collected for each match official during 8 official matches. Pre- and post-matches, the referees were assessed for tympanic temperature, blood lactate, 15- and 30-m sprint speeds and unilateral (dominant and non-dominant legs) and bilateral vertical jump performances. For referees, the acute physiological and physical performance effects of officiating (post-match value minus pre-match value) were large increases in blood lactate (1.7 mmol · l(-1); ±90% confidence limit, 0.9 mmol · l(-1); effect size, ES = 4.35), small increases in 15-m sprint (0.09; ±0.04 s; ES = 0.53) and 30-m sprint speeds (0.14; ±0.08 s; ES = 0.39) and a small increase in non-dominant leg jump performance (2.1; ±1.4 cm; ES = 0.31). For assistant referees, there was a small decrease in tympanic temperature (-0.3°C; ±0.2°C; ES = -0.65) and small increases in blood lactate (0.4; ±0.3 mmol · l(-1); ES = 0.66), 15-m sprint speed (0.06; ±0.04 s; ES = 0.47), 30-m sprint speed (0.11; ±0.16 s; ES = 0.49) and bilateral countermovement jump height (3.4; ±1.5 cm; ES = 0.45). Taken together, these data demonstrate that the physical demands of soccer officiating are sufficient to elicit increases in blood lactate and small decrements in sprint performance and, thereby, provide some evidence for match-related fatigue.


Asunto(s)
Rendimiento Atlético/fisiología , Fatiga/fisiopatología , Fútbol/fisiología , Adulto , Temperatura Corporal , Oído Medio/fisiología , Fatiga/etiología , Sistemas de Información Geográfica , Frecuencia Cardíaca , Humanos , Ácido Láctico/sangre , Aptitud Física/fisiología , Carrera/fisiología , España , Análisis y Desempeño de Tareas
10.
Res Sports Med ; 24(4): 308-319, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27547851

RESUMEN

The aim of this study was to examine the dose response effect of strength and conditioning programmes, involving horizontally oriented plyometric exercises, on relevant soccer performance variables. Sixteen soccer players were randomly allocated to two 6-week plyometric training groups (G1 and G2) differing by imposed (twice a week) training volume. Post-training G1 (4.13%; d = 0.43) and G2 (2.45%; d = 0.53) moderately improved their horizontal countermovement jump performance. Significant between-group differences (p < 0.01) in the vertical countermovement jump for force production time (T2) were detected post-training. No significant and practical (p > 0.05, d = trivial or small) post-training improvements in sprint, change of direction ability (CODA) and horizontal arm swing countermovement jump were reported in either group. Horizontal plyometric training was effective in promoting improvement in injury prevention variables. Doubling the volume of a horizontal plyometric training protocol was shown to have no additional effect over functional aspects of soccer players' performance.


Asunto(s)
Rendimiento Atlético/fisiología , Ejercicio Pliométrico/métodos , Fútbol/fisiología , Adulto , Traumatismos en Atletas/prevención & control , Humanos , Masculino , Fútbol/lesiones , España , Adulto Joven
11.
Coll Antropol ; 38(2): 533-8, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25144984

RESUMEN

The purposes of the study were to assess sprinting and agility performance characteristics and to determine the relationship between these two motor skills in elementary education students. Sprinting and agility performance were assessed in 176 children (88 boys and 88 girls) divided into three groups: Group 1 (G1, N = 98; 48 boys and 50 girls), from the first year of elementary education; Group 2 (G2, N = 38; 15 boys and 23 girls), from the second year of elementary education; Group 3 (G3, N = 40; 25 boys and 15 girls), from the third year of elementary education. Significant differences (p < 0.001) were found in agility ability among the groups and between G1-G3 and G2-G3 in the 5 and 15 m sprint. Regarding gender of the students of the same age, significant differences (p < 0.001) between boys and girls in group G1 and G2 were obtained in the 5 and 15 m sprint. The correlation between agility and acceleration was significant but moderate (0.3 < r < 0.7) in all groups (G1, G2, and G3), in most cases. When the gender factor was included, the results were heterogeneous. Assessing this correlation according to age and gender produced heterogeneous results. For this reason, we think that both are independent qualities and that age and gender are two factors that influence the correlation results.


Asunto(s)
Aceleración , Factores de Edad , Destreza Motora , Niño , Femenino , Humanos , Masculino
12.
J Sports Sci Med ; 12(3): 601-7, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24149171

RESUMEN

The aim of this study was to evaluate the effect of a different degree of contextual interference (CI) training program on the change of direction ability (CODA) itself and on the straight sprinting (SSP) performance (5 m and 15 m) in students in the first year of primary school. It also evaluated which CI training program was more effective. Eighty eight students (6.42 ± 0.38 yr) volunteered as participants for the present study. Participants were randomized into 5 different CI training programs (LCI: low contextual interference, MCI: moderate contextual interference, HCI: high contextual interference, VCI: variable contextual interference, and CG: control group) during a 3 week period. Significant CODA improvements (p < 0.05) in pre-post-test were found in MCI (4.39%, ES 0.41) and VCI (9.37%, ES 1. 12) groups. Furthermore, LCI, MCI and HCI groups ameliorated their SSP performance, both in 5 m (5. 92%, ES 0.81; 6.67%, ES 0.90; 8.05%, ES 1.33 respectively) and 15 m SSP (5.86%, ES 0.76; 6.47%, ES 0.80; 2.47% ES 0.41 respectively). These results suggest that training through games of tag (VCI) was the most effective in improving the CODA and training with moderate contextual interference (MCI) was the only type which induced improvements in both capacities (SSP and CODA). Key PointsWe investigated the CODA and SSP performance of students in the first year of primary school and the influence of 5 different training programs on their CODA and SSP ability.Training through games of tag (VCI) was the most effective in improving the CODATraining with moderate contextual interference (MCI) was the only one which induced improvements in both capacities (SSP and CODA).

13.
Coll Antropol ; 36(2): 529-34, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22856240

RESUMEN

The aims of the present study were to determine whether the estimations of the frontal area of the combined cyclist-bicycle (APCB) obtained with the Heil's non-logarithmic prediction equations (NPE) in the stem position (SP), brake hoods position (BHP) and drops position (DP) are comparable to the measured APCB with the computerized planimetry (CP) method, and to analyse with the CP method and the NPE the influence of the body position on the APCB. Nineteen participants competing in the Spanish Road Cycling First division took part in the study. The NPE overestimated the APCB in the BHP and in the DP compared with the measured APCB with the CP method (6.9% and 5.1%, respectively; p<0.05). Significant differences among the three positions were obtained with the CP method. The overestimation of the APCB with the NPE in the BHP and in the DP and the less sensitivity of the NPE to show significant differences between the SP and DP suggest that the NPE are not appropriate to accurately predict the APCB.


Asunto(s)
Movimientos del Aire , Ciclismo , Modelos Teóricos , Postura , Adolescente , Fenómenos Biomecánicos , Humanos , Masculino , Adulto Joven
14.
Artículo en Inglés | MEDLINE | ID: mdl-36613061

RESUMEN

The aims of this study were to analyze the heart rate response, the game temporal structure (i.e., mean total time of the matches, real playing time, total rest time) and the stroke technique distribution and to describe its relations in the table tennis national category in simulated competitions. A cohort of 60 table tennis male players (22.06 ± 8.32 years) played 30 simulated matches. The obtained results show a mean heart rate (HRmean) of 142.69 ± 14.10 bpm and a peak heart rate (HRpeak) of 167.26 ± 16.51 bpm. Total strokes were 7505, being the 57.88% and 42.12% forehand and backhand strokes, respectively. The most frequent forehand strokes were service (SERV) (33.13%) and forward spin technique (SPIN) (40.75%) stroke types, with the left quadrant of the table away from the net (Z_5) (25%) and right quadrant of the table away from the net (Z_6) (20.72%) being the most frequent ball bouncing placements. Meanwhile, the most frequent backhand strokes were backspin technique (PUSH) (42.74%) and SPIN (31.86%) stroke types, with the intermediate left quadrant of the table (Z_3) (17.21%), Z_5 (31.22%) and Z_6 (18.54%) being the most frequent ball placements. The mean total time of the matches was 15.74 ± 3.82 min, the mean real playing time was 4.14 ± 1.47 min and the total rest time was 11.60 ± 2.67 min. Heart rate variables did not correlate significantly with the different stroke types or the game temporal variables (p > 0.05). However, stroke types and game temporal structure variables were significantly correlated (p < 0.01). This information can be useful to reveal players' strengths and weaknesses and prepare subsequent training sessions, adapting training sessions to the needs of the athletes.


Asunto(s)
Tenis , Humanos , Masculino , Atletas , Mano , Frecuencia Cardíaca , Tenis/fisiología , Adolescente , Adulto Joven , Adulto
15.
Appl Ergon ; 103: 103784, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35489294

RESUMEN

This study aimed to determine the interactive physiological effect of backpack load carriage and slope during walking in professional mountain rescuers. Sixteen mountain rescuers walked on a treadmill at 3.6 km/h for 5 min in each combination of three slopes (1%, 10%, 20%) and five backpack loads (0%, 10%, 20%, 30%, and 40% body weight). Relative heart rate (%HRmax), relative oxygen consumption (%VO2max), and rating of perceived exertion (RPE, Borg 1-10 scale) were compared across conditions using two-way ANOVA. Significant differences in %VO2max, %HRmax, and RPE across slopes and loads were found where burden increased directly with slope and load (main effect of slope, p < 0.001 for all; main effect of load, p < 0.001 for all). Additionally, significant slope by load interactions were found for all parameters, indicating an additive effect (p < 0.001 for all). Mountain rescuers should consider the physiological interaction between slope and load when determining safe occupational walking capacity.


Asunto(s)
Trabajo de Rescate , Caminata , Fenómenos Biomecánicos , Frecuencia Cardíaca/fisiología , Humanos , Consumo de Oxígeno/fisiología , Estrés Fisiológico , Caminata/fisiología , Soporte de Peso/fisiología
16.
Gait Posture ; 92: 277-283, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34896839

RESUMEN

BACKGROUND: The Styrd Power Meter is gaining special interest for on-field gait analyses due to its low-cost and general availability. However, the reliability and validity of the Stryd during walking on positive slopes using different backpack loads have never been investigated. RESEARCH QUESTION: Is the Stryd Power Meter reliable and valid for quantifying gait mechanics during walking on positive inclines and during level walking incorporating load carriage? METHODS: Seventeen participants from a police force rescue team performed 8 submaximal walking trials for 5-min at 3.6 km·h-1 during different positive slope (1%, 10% and 20%) and backpack load (0%, 10%, 20%, 30% and 40% of body mass) conditions. Two Stryd devices were utilized for reliability analyses. Validity of cadence and ground contact time (GCT) were analyzed against a gold standard device (Optojump). RESULTS: The Stryd demonstrated acceptable reliability [mean bias: < 2.5%; effect size (ES): < 0.25; standard error of the mean: < 1.7%; r: > 0.76] for power, cadence, and GCT. Validity measures (mean bias: <0.8%; ES: <0.07; r: >0.96; Lin's Concordance Coefficient: 0.96; Mean Absolute Percent Error: <1%) for cadence were also found to be acceptable. The Stryd overestimated (P < 0.001; ES: >5.1) GCT in all the walking conditions. A significant systematic positive bias (P < 0.022; r = 0.56-0.76) was found in 7 conditions. SIGNIFICANCE: The Stryd Power Meter appears to produce reliable measurements for power output, cadence and GCT. The Stryd produced valid measurements for cadence during walking on positive slopes and during level walking with a loaded backpack. However, the Stryd is not valid for measuring GCT during these walking conditions. This study adds novel data regarding the reliability and validity of this device and might be of particular interest for scientists, practitioners, and first responders seeking reliable devices to quantify gait mechanics during walking.


Asunto(s)
Marcha , Caminata , Análisis de la Marcha , Humanos , Reproducibilidad de los Resultados
17.
J Sports Sci Med ; 10(4): 707-11, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-24149562

RESUMEN

The aim of the present study was to determine the effect of patellar taping (PT) on landing characteristics of the vertical ground reaction force (VGRF) and on flight time during a counter movement jump (CMJ). Eleven healthy male subjects (age: 31.1 ± 4.2 years) volunteered for the study. Each subject performed six CMJs under two different jumping conditions: with PT and without PT (WPT). The order of the two conditions was randomized. All of the measured variables had fair-to-good reliability (intra-class correlation coefficient > 0.75). When we compared the PT and WPT groups, we did not find a significant difference in the magnitude of the first (F1) and second (F2) peaks of the VGRF. We also did not find a significant difference in the time to production of these peaks (T1 and T2), and the time to stabilization (TTS) (p < 0. 05). Furthermore, the flight time was similar in the two groups (0.475 ± 0.046 and 0.474 ± 0.056 s, respectively, for PT and WPT). These results suggest that PT does not jeopardize performance during CMJ. Furthermore, it also does not soften the VGRF generated during the landing, indicating that PT may be of limited utility in preventing injuries associated with this type of movement. Key pointsWe investigated whether patellar taping interferes with athletic performance, as has been suggested by previous studies.We also explored the effect of patellar taping on the forces generated during the landing phase of counter movement jumps.Patellar taping had no effect on the flight time during counter movement jumps.Patellar taping also had no effect on the vertical ground reaction force variables measured during the landing phase of counter movement jumps.This information may be relevant to athletes and trainers who are concerned about the effects of patellar taping on performance.

18.
Artículo en Inglés | MEDLINE | ID: mdl-34501953

RESUMEN

The aims of this study were to: (1) analyze table tennis players' physical profiles considering and comparing players age categories (i.e., under U12, U14, U16, U20, Senior and Older); and (2) to quantify the correlations among the variables measured by each test. Seventy-one table tennis players (61 men and 10 women, 19.7 ± 11.23 years, 1.65 ± 0.13 m, 59.71 ± 17.72 kg and 21.60 ± 4.22 kg/m2) divided into six age groups, performed a sprint test, forearm isometric strength test, countermovement vertical test, countermovement horizontal test, change of direction ability (CODA) test and flexibility test. U14 players performed better than U12 in all tests (ES = -0.70 to 1.98, moderate to large) except in Sit and Reach (SAR) test (ES = 0.19, trivial). The U16 group also obtained better results than U14 in all tests (ES = 0.77 to -2.31, moderate to large) except for the SAR test (ES = 0.19, trivial). The U20 group performed better than U16 in all the tests (ES = 0.73 to -1.53, moderate to large) except for the 5 m sprint test (ES = -0.02, trivial), 10 m sprint test (ES = -0.51, moderate) and SAR (ES = 0.11, trivial). Differences between Senior and U20 were only found in the arm swing counter movement jump (CMJAS) (ES = -0.82, large) and modified agility test (MAT) (ES = 1.19, large), with the U20 group being better in both variables. The senior group performed better in the MAT test than the older group (ES = 0.94, large). The relation found between forearm isometric strength, vertical jump, horizontal jump, sprint and CODA ability (r = -0.53; ±0.14, 0/0/100, most likely to r = 0.83; ±0.06, 100/0/0, most likely) indicates that these capacities are related in table tennis players. Nevertheless, the lack of association between the sit and reach test with the other capacities may indicate that flexibility is an independent capacity.


Asunto(s)
Rendimiento Atlético , Tenis , Femenino , Humanos , Masculino , Movimiento , Aptitud Física
19.
J Hum Kinet ; 77: 107-115, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34168696

RESUMEN

The aim of this study was to compare heart rate variability indices before and after a table tennis match. Sixteen males (21.86 ± 8.34 yr, 1.73 ± 0.08 m, 64.09 ± 13.39 kg and 21.46 ± 4.38 kg·m-2) were evaluated in 21 matches, before and after the match. We observed that in time domain analysis, Mean RR, SDNN, LnRMSSD and pNN50 after match values were significantly lower than before match values (p < 0.01 or p < 0.05), while Mean HR, Min HR and Max HR values were higher (p < 0.01) after than before the match, with no significant differences (p > 0.05) in STD HR. Meanwhile, frequency domain analysis showed LF Power (log), HF Power (log) and HF Power (in normalized units) after match values significantly lower than before match values (p < 0.01 or p < 0.05), while LF/HF value was higher after the match (p < 0.01), with no significant differences (p > 0.05) in LF Power (ms2), LF Power (in normalized units) and HF Power (ms2) values. Non-linear analysis showed SD1 and SD2 POST values significantly lower than PRE values (p < 0.05), while no significant differences were observed in SD2/SD1 value between POST and PRE analysis. As conclusion, due to the physiological strain of the table tennis match, changes were observed in heart rate variability values, suggesting an increase of sympathetic influence and a reduction of the parasympathetic influence.

20.
J Hum Kinet ; 67: 123-131, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-31523311

RESUMEN

This study assessed gross efficiency (GE) during a single competitive season and determined the relationship between GE and maximum oxygen uptake (V̇O2max) in young elite cyclists (n = 15, 20.1 ± 1.4 yrs, 177.5 ± 5.7 cm, 68.3 ± 6.2 kg, 45.2 ± 7.5 mm of six skinfolds) during a competitive season. Participants completed at two occasions (T1 = April; T2 = July), a progressive bike protocol (initial intensity = 100 W, 35 W increments every 3 min) until volitional exhaustion to assess V̇O2max and submaximal variables. A single capillary blood sample was drawn from the left earlobe immediately after completion of each exercise load to determine lactate thresholds. Cyclists' GE was calculated as ([work accomplished/energy expended] x 100). No significant differences were obtained in GE at any workload between T1 and T2 or in the mean GE between T1 (19.3%) and T2 (19.4%) testing (p = 0.93). No significant association was found between mean GE and V̇O2max at either T1 (r = -0.28, p = 0.30), or T2 (r = -0.27, p = 0.32). GE of young elite cyclists might not vary during the most important phase of the training season and GE was not related to V̇O2max. A lower accumulated volume and intensity of training of these cyclists may account for their lower GE in comparison to older professional cyclists and might not have been enough to foster higher increases of GE in cyclists with lower V̇O2max.

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