Relación entre metodologías de control de la carga en el baloncesto profesional / Relationship Between Methodologies for Load Control in Professional Basketball

El objetivo de este trabajo fue determinar la relación existente entre diferentes metodologías de medición de la carga de entrenamiento en un equipo profesional de baloncesto. 12 jugadores de un mismo equipo fueron sometidos a estructuras de entrenamiento iguales en cuanto a diseño y fueron monitorizados diariamente con frecuencia cardiaca, GPS y percepción subjetiva de esfuerzo. Los resultados indicaron diferencias significativas entre todas las metodologías de control utilizadas. RPE (x2=12.4; P=.015), sRPE (x2=21.5; P<.001), TRIMP (x2=23.5; P<.001), SHRZ (x2=19.3; P<.001) y distancia (x2=21.7; P<.001). Se observó una correlación entre todas ellas exceptuando la variable distancia recorrida; Borg (p=.19; P=79), sRPE (p=.14; P=.299) y sHR-Z (p=.17; P=.197). Estos resultados sugieren que los diferentes métodos de evaluación utilizados para el control de la carga de entrenamiento determinan resultados variables en un equipo de baloncesto profesional. Se consideró que el ratio de esfuerzo percibido por sesión resulta el instrumento más eficaz para el control de la carga de entrenamiento. (AU)

The aim of this study was to determine the relationship between different load assessment methods in a professional basketball team. Twelve professional basketball players of the same team were subjected to the same training plan design and were monitored daily with heart rate monitors, GPS tools and perceived exertion scales. Results suggested that there were significant differences in training load between all monitoring methods: RPE (x2=12.4; P=.015), sRPE (x2=21.5; P<.001), TRIMP (x2=23.5; P<.001), SHRZ (x2=19.3; P<.001) and distance (x2=21.7; P<.001). Correlations were found between RPE and heart rate but not between these methods and the distance travelled during sessions: Borg (p=.19; P=79), sRPE (p=.14; P=.299) and sHR-Z (p=.17; P=.197). These results suggested that different load assessment methods render varying results in a professional basketball team. In this sample, perceived exertion rate was suggested as the best method for assessing training load in professional basketball players. (AU)

Time to exhaustion at estimated functional threshold power in road cyclists of different performance levels.

OBJECTIVES: This study assessed the functional threshold power and the time to exhaustion estimated from the Allen & Coggan test and verify whether performance level has an influence on this parameter. DESIGN: Cross-sectional study. METHODS: Twenty-minute test proposed by Allen & Coggan and cycling test to exhaustion were used to obtain the functional threshold power and a time to exhaustion. Cyclists were divided into performance groups based into 4 categories according to their VO2max. RESULTS: The median (interquartile range) time to exhaustion at the functional threshold power was 35 (31-38) minutes for recreationally trained cyclists, 42 (38-51) for trained ones, 47 (41-56) for well-trained ones and 51 (44-59) for professional level cyclists. Time to exhaustion increased with cyclists' experience and performance level (p < 0.001). CONCLUSIONS: The high time to exhaustion variability observed in this study suggests that functional threshold power and time to exhaustion should be assessed and reported independently for each subject. Also, cyclists' performance level and experience should be factored in when attempting to study the time to exhaustion, as better performing and more experienced cyclists consistently show longer times to exhaustion at the functional threshold power.

Effects of ergo-nutritional strategies on recovery in combat sports disciplines / Efectos de las estrategias ergo-nutricionales sobre la recuperación en las disciplinas de deportes de combate

In order to improve the recovery process in combat sports disciplines, ergo-nutritional strategies could be an effective option in training and competition. Some of these ergo-nutritional aids could improve performance but literature references are scarce, with controversial results regarding actual recovery effects. This systematic review aimed to examine which ergo-nutritional methods are most effective for assisting in the recovery process in combat sports, and to determine the appropriate training stimuli. This systematic review was carried out following the Preferred Reporting Items for Systematic Review (PRISMA) guidelines. A computerized search was performed in PubMed, Web of Science, the Cochrane Collaboration Database, Evidence Database, Evidence Based Medicine Search review, National Guidelines, EM-BASE, Scopus and Google Scholar system (from 1995 to April 30, 2021). The PICOS model was used to define inclusion and exclusion criteria. Out of 123 studies initially found, 18 met the eligibility criteria and were included in the review. Data from 367 athletes from different disciplines were examined. The evidence was grouped in 4 areas: oxidative stress, muscle and energy recovery, muscle repair, and metabolic acidosis. Evidence showed that vitamins, minerals, and some natural ergo-nutritional products are effective as antioxidants. Carbohydrates and protein determine the recovery effect. Sodium bicarbonate has a role as primary acidosis metabolic delayer. Accordingly, ergo-nutritional aids can help in the recovery process. Considering the effects outlined in the literature, more studies are needed to provide firm evidence (AU)

Para mejorar el proceso de recuperación en las disciplinas deportivas de combate, las estrategias ergo-nutricionales son una opción eficaz en el entrenamiento y la competición. Algunas de estas alternativas mejoran el rendimiento, pero actualmente existe una escasa bibliografía con resultados controvertidos relacionados con el efecto de recuperación. Esta revisión sistemática tuvo como objetivo determinar qué estrategias ergo-nutricionales son más efectivas en los procesos de recuperación. Se llevó a cabo siguiendo las pautas Preferred Reporting Items for Systematic Review (PRISMA). Se realizó una búsqueda computarizada en PubMed, Web of Science, Cochrane Collaboration Database, Evidence Database, Evidence Based Medicine Search review, National Guidelines, EM-BASE, Scopus y el sistema Google Scholar (desde 1995 hasta el 30 de abril de 2021). Se utilizó el modelo PICOS para definir los criterios de inclusión y exclusión. De los 123 estudios encontrados inicialmente, 18 cumplieron los criterios de elegibilidad y fueron incluidos. Se examinaron datos de 367 atletas de diferentes disciplinas. La evidencia se agrupó en 4 áreas: estrés oxidativo, recuperación muscular y energética, reparación muscular y acidosis metabólica. La evidencia mostró que las vitaminas, los minerales y algunos productos ergo-nutricionales naturales son eficaces como antioxidantes, los hidratos de carbono y las proteínas determinan su efecto recuperador y el bicarbonato de sodio es el principal retardador metabólico de la acidosis. Se destaca la importancia de aceptar un plan ergo-nutricional para mejorar el proceso de recuperación. A pesar de ello, y teniendo en cuenta los efectos descritos en la literatura, se necesitan más estudios para reforzar la evidencia actual (AU)

Influence of the Game Context and Levels of Physical Activity on the Behavior of Basketball Coaches / Influencia del Contexto de Juego y Niveles de Actividad Física en el Comportamiento de Entrenadores de Baloncesto

Coaches can exert a significant influence on players and games. The aim of this study is to assess behavior in the form of heart rate (HR) responses and distance traveled of basketball head coaches during matches considering the different match contexts faced as a score differences and time outs during the game direction and levels of physical activity and coaches experience. Four basketball head coaches are recruited in this case report. Mean and maximal absolute and relative HR are determined across matches. Scoring streaks (±6 consecutive points) and time outs are considered as influence value. The in-match distance traveled measured using microsensors, coaching experience, and daily activity on HR responses is also determined. Higher HR are evident across matches compared to periods prior to and following matches. HR is significantly (P <.05) elevated during later time-outs compared to earlier time-outs, with positive scoring streaks yielding a tendency towards higher HR compared to negative and no scoring streaks. Experience (rs = -0.91, P <.001), daily activity levels (rs = -0.83, P <.001), and weekly METS (rs = -0.78, P =.002) are negatively associated with match HR, while in-match distance (rs = 0.69, P =.013) is positively associated with match HR. These data indicate that matches elevate the cardiovascular stress imposed on basketball head coaches, with later time-outs and positive scoring streaks promoting heightened HR. Moreover, in-match activity and personal characteristics (less experience and lower physical activity) further augment match HR in coaches.(AU)

Influence of organised sports practice during adolescence on health of adult women with special emphasis on participation in aesthetic sports.

This study aimed to assess the differences in psychosocial health and cardiometabolic risk during adulthood in women based on previously organised sport (OS) participation during adolescence and current activity levels, with emphasis on participation in aesthetic sports. The study included 1947 women aged 18-55 years who were categorised into four groups: 355 aesthetic athletes during adolescence, 494 non- aesthetic athletes during adolescence, 791 non-athletes during adolescence with similar current levels of physical activity (PA) to OS groups and 307 currently inactive non-athletes during adolescence. Participants answered questionnaires regarding sport participation, psychosocial health and cardiometabolic risk. The results show that non-athletes during adolescence who are currently inactive reported significantly lower psychosocial health and higher cardiometabolic risk scores. Women with currently homogenous PA levels (χ² = 0.514) reported similar physical quality of life (QoL), exercise addiction, anxiety and depression symptoms regardless of participation in OS during adolescence (P > .05), except aesthetic athletes who reported the worst sleep and mental QoL. Very high training volumes in aesthetic athletes did not influence psychological outcomes and cardiometabolic risk in adulthood compared to lower training volumes. In conclusion, the effects of PA during adulthood appear to be powerful enough to induce beneficial adaptations in health outcomes that match those observed in women who participate in OS during adolescence, except for aesthetic sports participants, who show a high risk of lower quality of sleep in adulthood. PA should be promoted in adults and especially women who have not participated in OS during adolescence.

Anatomic and physiological correlates in bullfrog vestibular nerve.

1. The correlations between anatomic and physiological characteristics of primary afferent neurons innervating the anterior semicircular canal in the bullfrog were investigated. These characteristics were examined separately in large groups of neurons, and the direct correlations between them were established in a subset of neurons by means of intraaxonal recording and labeling. 2. Anatomic features of the anterior canalicular nerve that were related with fiber diameter were studied. This nerve was composed of an average of 1,142 fibers (standard deviation of 171 in 5 samples), of which 42% were less than 2 microns in diameter and 8% were greater than 7 microns. The nerve branched into 6 clearly defined bundles, whose fiber diameter-dependent composition could be determined in 5 samples. In the 2 center bundles, 32% of the fibers had diameters greater than 7 microns. In contrast, these thick fibers comprised only 4% of the fiber population in the 2 lateralmost bundles, in which 44% of the fibers had diameters less than 2 microns. The projections of labeled afferent fibers were traced into the neuroepithelium, and it was demonstrated that all thick fibers, even those of the lateral bundles, turned toward more central regions of the crista. Consequently, in the bullfrog, there is a clear predominance of thick afferent fibers innervating the anterior crista's central region and thin fibers in the peripheral region. 3. The dendritic morphology of the broad classes of afferent fibers (i.e., thick and thin) was elucidated. Individually labeled thick afferents possessed dendrites forming short, thick, clawlike extensions to contact a few hair cells. The thinnest afferents were labeled through extracellular horseradish peroxidase (HRP) injections. In contrast to the thick fibers, thin afferents were characterized by an unbranched trajectory with serially located bouton-like structures that were apposed to successive hair cells. 4. The characteristics of spontaneous firing and the responses to rotational stimuli were determined for 138 anterior canalicular neurons. Spontaneous firing rates ranged from 0 to 95 spikes.s-1. The coefficient of variation (CV) of spontaneous firing ranged from 0.12 to 2.5. Response gains to high- (0.5 and 0.4 Hz) and medium- (0.05 Hz) frequency sinusoidal acceleration stimuli were positively correlated with CV (P less than 0.001) for neurons with a CV value less than or equal to 0.5. The gain of neurons characterized by more irregular spontaneous firing (CV values greater than 0.5) was uncorrelated with CV.(ABSTRACT TRUNCATED AT 400 WORDS)

Differential effect of ischemia on spontaneous and sinusoidal-evoked activity in semicircular canal afferents in the bullfrog.

Spontaneous and sinusoidal-evoked nerve activity in semicircular canal afferent fibers of the bullfrog was evaluated prior to and following the production of ischemia of the labyrinthine arterial supply by mechanical occlusion of the vestibular artery. Neuronal spontaneous firing rates were observed to diminish by up to 100% within 10 min following the onset of ischemia. In most neurons there was a substantial increase in firing rate during the first few minutes. The sensitivity of the fibers to natural stimulation as determined by the gain in their responses to sinusoidal motion also diminished by as much as 75% over the same period. No detectable changes in the membrane potentials of the neurons were observed. The changes in excitability were closely correlated with the changes in spontaneous firing rate, but not all the neurons whose responses changed showed changes in spontaneous activity. Likewise, the relative magnitude of change varied from neuron to neuron.

Central projections of primary vestibular fibers in the bullfrog. III. The anterior semicircular canal afferents.

A study was made of the projection patterns in the vestibular nuclei of primary afferent fibers innervating the crista of the anterior semicircular canal (ASC) of the bullfrog. Individual neurons were intracellularly recorded to characterize their spontaneous activity and injected with horseradish peroxidase to visualize their central and peripheral projections. A quantitative evaluation was made of the lengths of the central projections of primary afferents in the various vestibular nuclei and of the number of branch terminals and their precise locations in each of the major vestibular projection areas in the brain stem. The differences between the central projection patterns of the two types of primary afferent fibers were documented: the thick fibers with their irregular spontaneous activity and the thin fibers with their more regular spontaneous activity. Each neuron sends many terminals to various vestibular nuclei. The ventral part of the ventral nucleus receives the greatest number of terminals from fibers of all sizes. The medial nucleus receives terminals from the thin fibers only, while the reticular formation receives terminals exclusively from the thick fibers. All the vestibular nuclei receive innervation from ASC afferents, with considerable overlap in areas of innervation between fibers of different caliber. Differences were found between the thick and thin fibers in their locations, their patterns of branching, and the appearance of their terminal boutons. These anatomic characteristics are interpreted to represent physiologic differences in the production of reflexes by thick and thin neurons. It is also postulated that these different neurons play different roles in vestibular system function: thick neurons contribute to the maintenance of equilibrium during movement while thin neurons participate in the maintenance of posture and vestibular tonus.

Central projections of primary vestibular fibers in the bullfrog. II. Nerve branches from individual receptors.

The fibers from the nerves innervating each of the three semicircular canals and the saccule were labeled by injecting horseradish peroxidase extracellularly into these nerves. The projections into the various vestibular nuclei of each receptor were studied in transverse sections of the brain stem throughout the vestibular nuclear area. All five vestibular nuclei receive primary afferents throughout their areas. There are differences in the projection patterns of the canals. In the superior and ventral vestibular nuclei, the location of the projections depends on the crista injected. The anterior canal projects ventrally, the horizontal canal centrally, and the posterior canal more dorsally. Each canal, however, sends fibers to all areas, with overlap of fibers from the different cristae. The cerebellar nucleus receives uniform innervation from the three canals. The medial vestibular nucleus in the rostral and caudal areas receives only thin fibers from each canal, with considerable overlap. The descending nucleus in the rostral and caudal areas receives innervation from the cristae, also with considerable overlap, but with greater intensity in the ventral part of the caudal portion of the nucleus. Each crista sends fibers to the cerebellar granular layer and to the base of the cerebellar Purkinje cell layer. These fibers also innervate the reticular formation below the entry zone of the eighth nerve. The saccule innervates both the dorsal (acoustic) and the ventral nuclei, the latter in the most dorsal position. The innervation of the utricle could be ascertained only in the middle section of the descending and the medial nuclei, an area which does not receive significant innervation from the cristae. Primary afferent fibers course in the vestibular tract, forming a longitudinal bundle lateral to the vestibular nuclei. In the bundle the larger fibers are medially situated.

Central projections of primary vestibular fibers in the bullfrog: I. The vestibular nuclei.

The central projections of the vestibular end organs in the bullfrog Rana calesbeiana were analyzed by using horseradish peroxidase labeling of the primary vestibular afferents. Separate extracellular injections were made of the anterior branch, the posterior branch, the ampullary nerve of each of the three semicircular canals, and the branch to the saccule. The anterior and posterior branches of the bullfrog eighth nerve, each containing both vestibular and auditory fibers, merge and enter the brain stem as a single nerve root. The thin caliber fibers of the anterior branch enter the brain stem on the ventral-posterior aspect of the nerve and immediately divide dichotomously into ascending (rostral) and descending (caudal) branches. The thick caliber fibers of the anterior branch enter the brain stem on the ventral-anterior aspect of the eighth nerve and traverse medially into the alar plate before dividing into ascending and descending branches. The primary afferent fibers of the vestibular nerve innervate an ipsilateral area of the brain stem which extends caudally from the rhombencephalon at the level of the twelfth nerve nucleus and rostrally up to and including the cerebellar nucleus and the cerebellum. The following vestibular nuclei can be identified by the fact that they receive primary vestibular afferents: the ventral vestibular nucleus, medial vestibular nucleus, descending vestibular nucleus, superior vestibular nucleus, and cerebellar nucleus. The dorsal (acoustic) nucleus, which receives primary auditory input, also receives afferents from the saccule. In addition to these nuclei, the cerebellum and the reticular formation receive significant primary input from the various vestibular receptors. The primary vestibulo-cerebellar fibers terminate mainly among the granular cells of the lobus auricularis and of the corpus cerebelli on the ipsilateral side. Each of the three semicircular canals projects into the cerebellum, while no such projection was observed in the saccular nerve preparations. Fibers from each of the three semicircular canals project to all of the vestibular nuclei. Heavily labeled large neurons, presumably vestibular efferents, are seen in the ipsilateral reticular formation, adjacent to the seventh motor nucleus.

Anatomical characteristics of the anterior vestibular nerve of the bullfrog.

Study was made of the dimensions of the nerves to the receptor organs in the anterior branch of the bullfrog vestibular nerve. The number of fibers and their diameters and trajectories in the nerve and Scarpa's ganglion were studied. A correlation was made between the anatomical and physiological properties of neurons identified with intracellular injections of horseradish peroxidase. The data suggest a specific pattern of innervation of the organs, organization of fibers and cells in the vestibular nerve, and significant correlation between the anatomical and physiological properties of individual neurons. A comparison was made between the information obtained from the bullfrog and that from other animals, which suggests a similarity between species and supports the hypothesis of a differential physiological role of the neurons in each vestibular organ according to anatomical characteristics.

Physiological and anatomical characteristics of primary vestibular afferent neurons in the bullfrog.

Intracellular recordings were made in the VIIIth nerve of the bullfrog (Rana catesbiana) to measure the membrane characteristics and obtain records of spontaneous and evoked spike activity of primary semicircular canal afferents. Physiological stimulation of the canals was achieved by rotating the preparation on a servomotor driven turntable with the animals' head centered in the rotational axis. The responses of each neuron to sinusoidal rotations at frequencies of 0.05Hz, 0.5Hz and for impulsive accelerations of 400 deg/sec2 were obtained. Membrane characteristics measured included the cell resting and action potential amplitude, and spike-activation threshold for applied currents. Physiologically characterized neurons were injected with horseradish peroxidase by applying pneumatic pressure and/or iontophoretic currents to the micropipettes containing 5% HRP in 1 M KCI. Following survival times of 12--48 h, the VIIIth nerve and attached vestibular end organ was removed for histochemical processing using a diaminobenzidine procedure to visualize the HRP reaction product. Light microscopy was used to discern the anatomical features of the neurons and to trace their peripheral dendritic trajectories from the ganglion to their termination(s) in the crista. Our studies have revealed that the bullfrog's primary vestibular afferents are characterized by a broad range of soma and axon diameters which correspond to an equally broad range of spontaneous and evoked activity characteristics. The largest neurons had more irregular spontaneous firing rates and consistently exhibited the greatest gain and smallest phase shifts with respect to head acceleration. These neurons consistently terminated at or near the central region of the crista. On the other hand, the smallest neurons were characterized by having the most regular spontaneous discharge patterns, the lowest gains, and greatest phase shifts with respect to head acceleration. Our findings are thus consistent with the view that the anatomical features of the primary vestibular neurons are important in determining the neuron's physiological characteristics. In terms of response dynamics our observations indicate that the receptors in the frog's crista ampullaris are heterogeneous and differentially sensitive to a wide range of stimulus frequencies.

Physiological basis of cochlear transduction and sensitivity.

Experiments were conducted in the guinea pig cochlea and the Xenopus laevis lateral line organ to obtain information about the electrical impedance properties of the cochlea, the sources and characteristics of the cochlear potentials, and to determine if hair cells are electrically excitable. The significance of the resting and evoked cochlear potentials in the transduction process leading to excitation of the acoustic nerve fibers was evaluated by comparing the results of electrophysiological experiments with the prediction of a model of the cochlea designed after the mechanoelectric theory of hair cell function. The results of these experiments 1) were compatible with the prediction of the mechoelectric theory of cochlear function; 2) made it possible to estimate and compare the energy dissipated in generating and maintaining the cochlear potentials with the stores of biochemical energy available in the cochlea; and 3) showed that the hair cells are electrically excitable, from which it was concluded that interaction between the hair cells is feasible.