Respuesta cardíaca en reposo y durante el esfuerzo submáximo en el proceso de aclimatación a la altura: implicaciones para el entrenamiento

En condiciones de hipoxia en altura, la capacidad de rendimiento físico está disminuida debido a la menor disponibilidad de oxígeno. La frecuencia cardíaca (FC) está muy relacionada con la cantidad de oxígeno que llega a los músculos, por lo que el fin de este trabajo es conocer la respuesta que tiene la FC en altura, tanto en situación de reposo como durante el ejercicio de intensidad submáxima. Para ello se estudió a los 4 participantes de una expedición al Himalaya, tanto en situación de reposo, como durante un test de esfuerzo submáximo, que consistía en subir y bajar de un escalón de 30 cm, 30 veces por minuto durante 3 minutos. La FC en reposo, aumentó significativamente con la altura (P<0.05). En cambio, la FC durante el esfuerzo submáximo disminuyó de forma significativa con la altura y el tiempo de permanencia en ella (P<0.05). En conclusión, este estudio demuestra que la frecuencia cardíaca durante el esfuerzo submáximo a intensidad constante disminuye con la permanencia a gran altura. Estos resultados son de interés para el control de la intensidad del esfuerzo en montaña y/o durante el entrenamiento en altura

Heart Rate Variability and Exceptional Longevity

Centenarians are the paradigm of human extreme longevity and healthy aging, because they have postponed, if not avoided, mayor age-related diseases. The purpose of this study was to investigate potential differences in resting heart rate variability (HRV) between young adults, octogenarians, and centenarians and assess whether HRV variables are predictors of all-cause mortality in centenarians. To this end, three groups of participants: young adults (N = 20; 20.6 ± 2.3 years), octogenarians (N = 18; 84.1 ± 2.6 years), and centenarians (N = 17; 101.9 ± 1.9 years) were monitored for 15 min at rest (seated, without moving or talking) to measure RR intervals, from which HRV was evaluated. Our results showed a clear decrease with age in the main parasympathetic HRV variables, as well as in the standard deviation (SD) of the RR series [SD of normal-to-normal interval (SDNN)] and in low frequency (LF) heart rate (HR) oscillations, although differences between octogenarians and centenarians did not reach statistical significance. In 14 centenarians followed until death, only SDNN showed significant correlation (¿ = 0.536; p = 0.048) with survival prognosis. Additionally, SDNN <19 ms was associated with early mortality (=1 year) in centenarians (Hazard Ratio = 5.72). In conclusion, HRV indices reflecting parasympathetic outflow as well as SDNN and LF all present an age-related reduction, which could be representative of a natural exhaustion of allostatic systems related to age. Moreover, low SDNN values (<19 ms) could be associated with early mortality in centenarians. HRV seems to play a role in exceptional longevity, which could be accounted for by centenarians’ exposome

Paleoseismological analysis of late Miocene lacustrine successions in the Prebetic Zone, SE Spain

A paleoseismological study of late Miocene lacustrine sediments was carried out in the Neogene basins of the Prebetic Zone in Albacete (Spain). We developed a multidisciplinary methodology which could be used to extrapolate the paleoseismic data to the present day. This multidisciplinary approach includes different disciplines, i.e. stratigraphy, structural analysis, seismological analysis and paleoseismology. Paleoseismological analysis was focussed on both shallow and deep lake deposits given that these sediments behave differently in different deformation fields. The seismites formed in shallow sediments were generated by liquefaction and include: sand dikes, pillow structures and intruded and fractured gr avels. The deep lake deposits show varied structures, such as loop bedding, disturbed varved lamination, mixed layers and pseudonodules. Seismites indicate paleoearthquake magnitude intervals. The trends of the seismites are usually oriented ve ry close to the stress field trends (from the late Miocene to the Present): NW-SE and NE-SW trends. This constitutes a link between tectonics and seismites. The va rved annual sedimentation evidenced by the deep lake facies was used as a relative dating method. Mixed layers were employed as paleoseismic indicators to calculate the earthquake recurrence interval. The mean recurrence interval is close to 130 years (9446 years of total record with 73 dated events), one maximum interval of 454 years and one minimum interval of 23 years and the mean estimated magnitude value is 5.1. The Gutenberg-Richter relationship shows similar "b" values close to 0.86 from paleoseismological and seismological data. This suggests that the seismic conditions have been similar since the late Miocene

Physical activity in centenarians beyond cut-point-based accelerometer metrics

This study described and compared physical activity (PA) characteristics at the end of the human lifespan using conventional cut-point-based versus cut-point-free accelerometer metrics. Eighteen institutionalized centenarians (101.5 ± 2.1 years, 72.2% female, 89% frail) wore the wrist GENEActiv accelerometer for 7 days. Conventional metrics, such as time spent in light-intensity PA (LiPA) and moderate-to-vigorous intensity PA (MVPA) were calculated according to published cut-points for adults and older adults. The following cut-point-free metrics were evaluated: average acceleration, intensity gradient and Mx metrics. Depending on the cut-point, centenarians accumulated a median of 15–132 min/day of LiPA and 3–15 min/day of MVPA. The average acceleration was 9.2 mg [Q1: 6.7 mg–Q3: 12.6 mg] and the intensity gradient was −3.19 [−3.34–−3.12]. The distribution of Z-values revealed positive skew for MVPA, indicating a potential floor effect, whereas the skew magnitude was attenuated for cut-point-free metrics such as intensity gradient or M5. However, both cut-point-based and cut-point-free metrics were similarly positively associated with functional independence, cognitive and physical capacities. This is the first time that PA has been described in centenarians using cut-point-free metrics. Our results suggest that new analytical approaches could overcome cut-point limitations when studying the oldest-old. Future studies using these new cut-point-free PA metrics are warranted to provide more complete and comparable information across groups and populations

Acute effects of long-distance races on heart rate variability and arterial stiffness: A systematic review and meta-analysis

This study systematically reviewed and quantified the effects of running a long-distance race (LDR) on heart rate variability (HRV) and arterial stiffness (AS). All types of races of a distance equal to or greater than a marathon (=42.2 km) were included. A total of 2, 220 articles were identified, 52 were included in the qualitative analysis, and 48 were meta-analysed. The standardised mean difference pre- and post-race of various time-domain and frequency-domain indices of HRV, mean arterial blood pressure (MAP), systolic blood pressure (SBP), diastolic blood pressure (DBP) and carotid-femoral pulse wave velocity (cfPWV) was calculated. Regarding HRV, there was a significant decrease in most of the variables considered as markers of parasympathetic activity, indicating a shift of autonomic balance towards a reduced vagal tone. Regarding vascular variables, there was a significant drop in blood pressure and reduced AS. In conclusion, running an LDR seems to have a considerable acute effect on the autonomic nervous system, haemodynamics, and vascular properties. The observed effects could be categorised within the expected acute responses to long-lasting, strenuous exercise. © 2021 Informa UK Limited, trading as Taylor & Francis Group

Masa muscular, fuerza isométrica y dinámica en las extremidades inferiores de niños y adolescentes con síndrome de Down

En general se ha observado que las personas con síndrome de Down (SD) tienen valores inferiores de fuerza muscular comparados con personas sin SD. También existe un déficit de masa muscular en los adultos con SD comparados con otros sin SD. Sin embargo, ningún estudio hasta la fecha había evaluado esta masa muscular en población pediátrica. Nuestro estudio pretende poner de manifiesto si también a edades tempranas existe un déficit de masa muscular y además relacionar ambos valores. Los niños y adolescentes con y sin SD (15±3 y 14±3 años respectivamente) de nuestro estudio obtuvieron valores similares de masa muscular ajustada por talla y estadio puberal, pero el grupo con SD obtuvo valores inferiores de fuerza (p<0.05). Además de esto, el grupo con SD ejerció menos kilogramos de fuerza por cada kilogramo de masa muscular. Alguna causa fisiológica o de transmisión podría explicar esta falta de fuerza ya que, al menos en esta franja de edad no existe un déficit de masa muscular. Deberían incentivarse los programas de entrenamiento específicos para este tipo de población para comprobar si es posible un incremento en su fuerza muscular.Generally it has been observed that population with Down syndrome (DS) has lower levels of muscular strength compared with others without DS. It is also known a deficit between muscular mass between adults with and without DS. However, there are no studies until the date which evaluated muscular mass in paediatric populations. Our study pretends to show whether also in earlier ages it does exist a deficit in the muscular mass and also to relate both values. Children and adolescents with and without DS (15±3 y 14±3 years respectively) from the study had similar values of muscular mass adjusted by height and puberal status, but DS group obtained lower values in all strength parameters. In addition, DS group also performed less kilograms of strength by kilogram of muscular mass. Some physiological or transmission impairment could explain this lack of strength as it known that there are not deficit in the muscular mass. Specific and adapted for this population training programs should be promoted to check whether an enhancement in their muscular strength is possible.Peer Reviewe

Paleoseismological analysis of late Miocene lacustrine successions in the Prebetic Zone, SE Spain

El estudio paleosismológico en las cuencas neógenas (Mioceno superior) lacustres del Prebético de Albacete ha sido abordado mediante un enfoque multidisciplinar para poder extrapolar los datos paleosímicos a la actualidad. Dicho enfoque integra las siguientes disciplinas: estratigrafía, análisis estructural, análisis de la sismicidad y paleosismología. El estudio paleosismológico se ha realizado en depósitos de facies someras y profundas, ya que los sedimentos de ambas zonas presentan un comportamiento diferente frente a la deforrmación. Las sismitas localizadas en sedimentos someros fueron generadas por fenómenos de licuefacción y son: diques de arena, estructuras en almohadilla y licuefacción y fracturación en gr avas. Las zonas profundas presentan estructuras más diversas: loop bedding, alteración de la estructura planar de va rvas, niveles de mezcla y pseudonódulos. Las sismitas estudiadas se pueden utilizar como indicadores de intervalos de magnitudes sísmicas. Las estructuras se orientan sistemáticamente según los campos de esfuerzo reciente y actual (que se mantienen desde el Mioceno superior hasta la actualidad): NW-SE y NE-SW. Éste es un punto que permite relacionar genéticamente la tectónica y las sismitas. Se ha utilizado el carácter anual de la sedimentación va rvada para datar de forma relativa las estructuras y establecer periodos de recurrencia de paleoterremotos. El intervalo de recurrencia medio está próximo a los 130 años (9.446 años de registro total y 73 eventos datados), el intervalo máximo es de 454 años y el mínimo de 23 años y la magnitud media estimada es de 5,1. Se ha aplicado la ley de Gutenberg-Richter a los datos paleosísmicos y de sismicidad actual y se obtienen valores del parámetro "b" muy similares, próximos a 0,86. Todas estas premisas indican que las condiciones de la sismicidad en el Mioceno superior fueron muy similares a las actuales.A paleoseismological study of late Miocene lacustrine sediments was carried out in the Neogene basins of the Prebetic Zone in Albacete (Spain). We developed a multidisciplinary methodology which could be used to extrapolate the paleoseismic data to the present day. This multidisciplinary approach includes different disciplines, i.e. stratigraphy, structural analysis, seismological analysis and paleoseismology. Paleoseismological analysis was focussed on both shallow and deep lake deposits given that these sediments behave differently in different deformation fields. The seismites formed in shallow sediments were generated by liquefaction and include: sand dikes, pillow structures and intruded and fractured gr avels. The deep lake deposits show varied structures, such as loop bedding, disturbed varved lamination, mixed layers and pseudonodules. Seismites indicate paleoearthquake magnitude intervals. The trends of the seismites are usually oriented ve ry close to the stress field trends (from the late Miocene to the Present): NW-SE and NE-SW trends. This constitutes a link between tectonics and seismites. The va rved annual sedimentation evidenced by the deep lake facies was used as a relative dating method. Mixed layers were employed as paleoseismic indicators to calculate the earthquake recurrence interval. The mean recurrence interval is close to 130 years (9446 years of total record with 73 dated events), one maximum interval of 454 years and one minimum interval of 23 years and the mean estimated magnitude value is 5.1. The Gutenberg-Richter relationship shows similar "b" values close to 0.86 from paleoseismological and seismological data. This suggests that the seismic conditions have been similar since the late Miocene

Hand span influences optimal grip span in adolescents with Down syndrome

Introduction: The hand grip strength test provides useful and reliable information about overall health. Different studies have investigated the optimal grip span for determining maximal hand grip strength in different populations such as adults, adolescents and children without disabilities. Objective: To ascertain whether there is an optimal grip span for determining maximal hand grip strength in adolescents with Down syndrome (DS). Methods: Twenty-seven right-handed youths with DS (seven females) aged 15.5 ± 3.6 years were evaluated in this methodological study. Each hand was randomly tested on ten times using five different grip spans, allowing one-minute rest between attempts. The hand span was measured from the tip of the thumb to the tip of the small finger with the hand widely opened. To confirm the usefulness of the optimal grip span, a new group of 15 adolescents with DS were recruited. Results: An optimal grip span was identified for the dominant hand in adolescents with DS. The equation relating grip span as a function of dominant hand span in this group is formulated as follows: y = 0.342x - 1.161 cm (r = 0.63, p < 0.05). In the case of non-dominant hand, a tendency towards a linear association (p = 0.058) was found; the equation is formulated as follows: y = 0, 210x + 1.324 cm. Conclusion: It is important to standardize the procedure and increase reliability when measuring hand grip strength in DS population. The values stated in this study are recommended to assess hand grip strength in adolescents with Down syndrome

Validity of the polar h7 heart rate sensor for heart rate variability analysis during exercise in different age, body composition and fitness level groups

This work aims to validate the Polar H7 heart rate (HR) sensor for heart rate variability (HRV) analysis at rest and during various exercise intensities in a cohort of male volunteers with different age, body composition and fitness level. Cluster analysis was carried out to evaluate how these phenotypic characteristics influenced HR and HRV measurements. For this purpose, sixty-seven volunteers performed a test consisting of the following consecutive segments: sitting rest, three submaximal exercise intensities in cycle-ergometer and sitting recovery. The agreement between HRV indices derived from Polar H7 and a simultaneous electrocardiogram (ECG) was assessed using concordance correlation coefficient (CCC). The percentage of subjects not reaching excellent agreement (CCC &gt; 0.90) was higher for high-frequency power (PHF) than for low-frequency power (PLF) of HRV and increased with exercise intensity. A cluster of unfit and not young volunteers with high trunk fat percentage showed the highest error in HRV indices. This study indicates that Polar H7 and ECG were interchangeable at rest. During exercise, HR and PLF showed excellent agreement between devices. However, during the highest exercise intensity, CCC for PHF was lower than 0.90 in as many as 60% of the volunteers. During recovery, HR but not HRV measurements were accurate. As a conclusion, phenotypic differences between subjects can represent one of the causes for disagreement between HR sensors and ECG devices, which should be considered specifically when using Polar H7 and, generally, in the validation of any HR sensor for HRV analysis

Recreational water skiing in people with paraplegia: A study of three cases

Objetivos: se analizaron la condición cardiorrespiratoria y la intensidad de esfuerzo durante la práctica recreativa del esquí náutico de slalom. Metodología: participaron tres esquiadores náuticos con paraplejia moderadamente activos. Realizaron un test incremental en un ergómetro de brazos para determinar su VO2pico y los umbrales ventilatorios y completaron 3 sesiones de práctica de esquí náutico, separadas por 48h, registrándose la FC cada 5 s. Resultados: obtuvieron un VO2pico de 22,3 ± 0,6 mL·kg-1·min-1 y los umbrales ventilatorios se analizaron al ~80 y ~50% del VO2pico. La FC media en las sesiones de esquí náutico fue de 111 ppm, lo que representó una intensidad de ~45% de la FC de reserva (FCR), permaneciendo por encima del 40% de la FCR ~12 min. Conclusión: la intensidad moderada de la práctica recreativa de esquí náutico de slalom podría servir para mantener o mejorar la condición cardiorrespiratoria en estas tres personas con paraplejiaObjectives: the cardiorespiratory fitness and the intensity of effort were analyzed during the recreational practice of slalom water skiing. Methodology: three moderately active water skiers with paraplegia participated. They performed an incremental test on an arm ergometer to determine their VO2peak and ventilatory thresholds and completed 3 sessions of water skiing, separated by 48h, where the HR was recorded every 5 s. Results: they obtained a VO2peak of 22.3 ± 0.6 mL·kg-1·min-1 and the ventilatory thresholds were analyzed at ~80 and ~50% of the VO2peak. The average heart rate in the water ski sessions was 111 bpm, which represented an intensity of ~45% of the heart rate reserve (HRR), remaining above 40% of the HRR ~12 min. Conclusion: the moderate intensity of recreational slalom skiing could serve to maintain or improve the cardiorespiratory fitness in these three people with paraplegi