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1.
Int J Behav Nutr Phys Act ; 21(1): 54, 2024 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-38720323

RESUMEN

BACKGROUND: Transportation policies can impact health outcomes while simultaneously promoting social equity and environmental sustainability. We developed an agent-based model (ABM) to simulate the impacts of fare subsidies and congestion taxes on commuter decision-making and travel patterns. We report effects on mode share, travel time and transport-related physical activity (PA), including the variability of effects by socioeconomic strata (SES), and the trade-offs that may need to be considered in the implementation of these policies in a context with high levels of necessity-based physical activity. METHODS: The ABM design was informed by local stakeholder engagement. The demographic and spatial characteristics of the in-silico city, and its residents, were informed by local surveys and empirical studies. We used ridership and travel time data from the 2019 Bogotá Household Travel Survey to calibrate and validate the model by SES. We then explored the impacts of fare subsidy and congestion tax policy scenarios. RESULTS: Our model reproduced commuting patterns observed in Bogotá, including substantial necessity-based walking for transportation. At the city-level, congestion taxes fractionally reduced car use, including among mid-to-high SES groups but not among low SES commuters. Neither travel times nor physical activity levels were impacted at the city level or by SES. Comparatively, fare subsidies promoted city-level public transportation (PT) ridership, particularly under a 'free-fare' scenario, largely through reductions in walking trips. 'Free fare' policies also led to a large reduction in very long walking times and an overall reduction in the commuting-based attainment of physical activity guidelines. Differential effects were observed by SES, with free fares promoting PT ridership primarily among low-and-middle SES groups. These shifts to PT reduced median walking times among all SES groups, particularly low-SES groups. Moreover, the proportion of low-to-mid SES commuters meeting weekly physical activity recommendations decreased under the 'freefare' policy, with no change observed among high-SES groups. CONCLUSIONS: Transport policies can differentially impact SES-level disparities in necessity-based walking and travel times. Understanding these impacts is critical in shaping transportation policies that balance the dual aims of reducing SES-level disparities in travel time (and time poverty) and the promotion of choice-based physical activity.


Asunto(s)
Ejercicio Físico , Transportes , Caminata , Humanos , Colombia , Transportes/métodos , Caminata/estadística & datos numéricos , Impuestos , Factores Socioeconómicos , Ciudades , Ciclismo/estadística & datos numéricos , Femenino , Masculino , Adulto
2.
BMC Anesthesiol ; 24(1): 171, 2024 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-38714926

RESUMEN

BACKGROUND: Older critically ill patients experience rapid muscle loss during stay in an intensive care unit (ICU) due to physiological stress and increased catabolism. This may lead to increased ICU length of stay, delayed weaning from ventilation and persistent functional limitations. We hypothesized that with optimal nutrition and early physical therapy acting in synergism, we can reduce muscle mass loss and improve functional outcomes. METHODS: This was a prospective, single blinded randomized, controlled single-center pilot study to compare the lean muscle mass (measured at bilateral quadriceps femoris using ultrasound) of older ICU patients at 4 time points over 14 days between the control and intervention groups. The control group received standard weight-based empiric feeding and standard ICU physiotherapy. The intervention group received indirect calorimetry directed feeding adjusted daily and 60 min per day of cycle ergometry. 21 patients were recruited and randomized with 11 patients in the control arm and 10 patients in the intervention arm. Secondary outcome measures included ICU and hospital mortality, length of stay, functional assessments of mobility and assessment of strength. RESULTS: Median age was 64 in the control group and 66 in the intervention group. Median calories achieved was 24.5 kcal/kg per day in the control group and 23.3 kcal/kg per day in the intervention group. Cycle ergometry was applied to patients in the intervention group for a median of 60 min a day and a patient had a median of 8.5 sessions in 14 days. Muscle mass decreased by a median of 4.7cm2 in the right quadriceps femoris in the control group and 1.8cm2 in the intervention group (p = 0.19), while the left quadriceps femoris decreased by 1.9cm2 in the control group and 0.1cm2 in the intervention group (p = 0.51). CONCLUSION: In this pilot study, we found a trend towards decrease muscle loss in bilateral quadriceps femoris with our combined interventions. However, it did not reach statistical significance likely due to small number of patients recruited in the study. However, we conclude that the intervention is feasible and potentially beneficial and may warrant a larger scale study to achieve statistical significance. TRIAL REGISTRATION: This study was registered on Clinicaltrials.gov on 30th May 2018 with identifier NCT03540732.


Asunto(s)
Calorimetría Indirecta , Unidades de Cuidados Intensivos , Tiempo de Internación , Humanos , Proyectos Piloto , Masculino , Anciano , Femenino , Calorimetría Indirecta/métodos , Estudios Prospectivos , Persona de Mediana Edad , Método Simple Ciego , Enfermedad Crítica/terapia , Ciclismo/fisiología , Ingestión de Energía/fisiología , Músculo Cuádriceps , Mortalidad Hospitalaria
3.
Scand J Med Sci Sports ; 34(5): e14667, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38773919

RESUMEN

The relationship between exercise-induced troponin elevation and non-obstructive coronary artery disease (CAD) is unclear. This observational study assessed non-obstructive CAD's impact on exercise-induced cardiac Troponin I (cTnI) elevation in middle-aged recreational athletes. cTnI levels of 40 well-trained recreational athletes (73% males, 50 ± 9 years old) were assessed by a high-sensitive cTnI assay 24 h before, and at 3 and 24 h following two high-intensity exercises of different durations; a cardiopulmonary exercise test (CPET), and a 91-km mountain bike race. Workload was measured with power meters. Coronary computed tomography angiography was used to determine the presence or absence of non-obstructive (<50% obstruction) CAD. A total of 15 individuals had non-obstructive CAD (Atherosclerotic group), whereas 25 had no atherosclerosis (normal). There were higher post-exercise cTnI levels following the race compared with CPET, both at 3 h (77.0 (35.3-112.4) ng/L vs. 11.6 (6.4-22.5) ng/L, p < 0.001) and at 24 h (14.7 (6.7-16.3) vs. 5.0 (2.6-8.9) ng/L, p < 0.001). Absolute cTnI values did not differ among groups. Still, the association of cTnI response to power output was significantly stronger in the CAD versus Normal group both at 3 h post-exercise (Rho = 0.80, p < 0.001 vs. Rho = -0.20, p = 0.33) and 24-h post-exercise (Rho = 0.87, p < 0.001 vs. Rho = -0.13, p = 0.55). Exercise-induced cTnI elevation was strongly correlated with exercise workload in middle-aged athletes with non-obstructive CAD but not in individuals without CAD. This finding suggests that CAD influences the relationship between exercise workload and the cTnI response even without coronary artery obstruction.


Asunto(s)
Enfermedad de la Arteria Coronaria , Prueba de Esfuerzo , Ejercicio Físico , Troponina I , Humanos , Masculino , Persona de Mediana Edad , Enfermedad de la Arteria Coronaria/sangre , Femenino , Troponina I/sangre , Ejercicio Físico/fisiología , Adulto , Ciclismo/fisiología , Carga de Trabajo , Angiografía por Tomografía Computarizada , Atletas , Angiografía Coronaria
4.
Technol Cult ; 65(2): 473-495, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38766958

RESUMEN

This article explores why white supremacists regard self-directed mobility by people of color as threatening by examining a controversy that unfolded in a mining town called Springs during the apartheid era in South Africa. Drawing on archives, oral histories, and testimonies, it shows how white residents of Selcourt and Selection Park, along with their allies in the town council, prevented Black workers from walking and cycling through the suburbs. Infrastructure and social disciplinary institutions proved effective in forcing Black workers to largely comply. It argues that the white supremacist disciplinary imperative against the workers arose directly from the characteristics of their mode of mobility. In their open embodiment, free from the confines of mechanized transport, and slow speeds, the workers engaged in a sustained refusal of spatial segregation. The article highlights how racial difference as an analytical category sheds light on mobility control within regimes of white supremacy.


Asunto(s)
Caminata , Sudáfrica , Historia del Siglo XX , Humanos , Caminata/historia , Población Negra/historia , Ciclismo/historia , Apartheid/historia , Racismo/historia , Relaciones Raciales/historia
6.
BMJ Case Rep ; 17(5)2024 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-38782431

RESUMEN

A female patient in her middle childhood presented to the paediatric emergency room (ER) after a bicycle accident with an abdominal impact on the bicycle handlebar. On physical examination, a painful ecchymosis on the upper left quadrant was the only abnormal finding. Abdominal ultrasound showed no intra-abdominal lesions, and the patient was discharged home after 24 hours under monitoring. Nine days after the accident, she returned to the ER due to the emergence of an abdominal mass around the area of impact. Abdominal examination detected a tender non-fluctuating mass on the epigastric and left hypochondrium, and abdominal ultrasound revealed a muscle and aponeurosis disruption of the rectus muscle, with fat herniation and cytosteatonecrosis. A conservative approach was chosen, with ambulatory follow-up. One month after the accident, the patient was asymptomatic, no abdominal mass was palpable, and an abdominal CT showed a reduction of the muscle disruption and hernial content.


Asunto(s)
Ciclismo , Hernia Abdominal , Humanos , Ciclismo/lesiones , Femenino , Hernia Abdominal/etiología , Hernia Abdominal/diagnóstico por imagen , Niño , Traumatismos Abdominales/complicaciones , Traumatismos Abdominales/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Ultrasonografía , Pared Abdominal/diagnóstico por imagen
7.
Int J Behav Nutr Phys Act ; 21(1): 59, 2024 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-38773559

RESUMEN

BACKGROUND: Physical inactivity is a major public health concern, exacerbated in countries with a (sub)tropical climate. The built environment can facilitate physical activity; however, current evidence is mainly from North American and European countries with activity-friendly climate conditions. This study explored associations between built environment features and physical activity in global tropical or subtropical dry or desert climate regions. METHODS: A systematic review of four major databases (Web of Science, Scopus, PubMed, and SportDISCUS) was performed. To be included, studies had to investigate associations between perceived or objective built environment characteristics and adult's physical activity and had to be conducted in a location with (sub)tropical climate. Each investigated association was reported as one case and results were synthesized based upon perceived and objectively assessed environment characteristics as well as Western and non-Western countries. Study quality was evaluated using a tool designed for assessing studies on built environment and physical activity. RESULTS: Eighty-four articles from 50 studies in 13 countries with a total of 2546 built environment-physical activity associations were included. Design (connectivity, walking/cycling infrastructure), desirability (aesthetics, safety), and destination accessibility were the built environment characteristics most frequently associated with physical activity across the domains active transport, recreational physical activity, total walking and cycling, and moderate-to-vigorous physical activity, particularly if multiple attributes were present at the same time. Very few studies assessed built environment attributes specifically relevant to physical activity in (sub)tropical climates. Most studies were conducted in Western countries, with results being largely comparable with non-Western countries. Findings were largely generalizable across gender and age groups. Results from natural experiments indicated that relocating to an activity-friendly neighborhood impacted sub-groups differently. CONCLUSIONS: Built environment attributes, including destination accessibility, connectivity, walking and cycling infrastructure, safety, and aesthetics, are positively associated with physical activity in locations with (sub)tropical climate. However, few studies focus on built environment attributes specifically relevant in a hot climate, such as shade or indoor recreation options. Further, there is limited evidence from non-Western countries, where most of the urban population lives in (sub)tropical climates. Policy makers should focus on implementing activity-friendly environment attributes to create sustainable and climate-resilient cities.


Asunto(s)
Entorno Construido , Ejercicio Físico , Clima Tropical , Caminata , Humanos , Caminata/estadística & datos numéricos , Adulto , Planificación Ambiental , Ciclismo/estadística & datos numéricos , Características de la Residencia
8.
BMC Geriatr ; 24(1): 435, 2024 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-38755554

RESUMEN

BACKGROUND: The transition into residential aged care is frequently associated with a reduction in physical activity, social engagement, and emotional wellbeing. Our aim was to evaluate the impact of a 26-day international cycling competition (Road Worlds Competition for Seniors), incorporating elements of exercise, audiovisual cycling footage, social engagement, and gamification, on the physical, psychological, and social well-being of aged care residents. We aimed to use findings to inform the development of a multi-modal intervention model to maximise wellbeing for older adults. METHODS: Residents (N = 32) participated in a mixed-methods single-group intervention pilot study that compared pre-and post-competition measures for the following wellbeing domains; physical, psychological, and social. In addition, interviews were conducted with residents (n = 27) and staff (n = 6) to explore their experiences. RESULTS: Measures identified significant improvements across multiple wellbeing domains, including functional fitness, depression, self-efficacy, and social network sizes. Findings from the interview data indicated that the multimodal components involved in the program delivery were valued by staff and residents who enjoyed the gamification, audiovisual cycling footage, social engagement, opportunities for reminiscence, and camaraderie between peers, staff, and volunteers. CONCLUSIONS: Findings highlight a constellation of benefits across physical, psychological, and social domains of wellbeing and inform a model for innovative multidimensional programs in residential aged care. The benefits for residents with varying physical and cognitive abilities support the use of creative strategies that maximise inclusion and engagement for residents.


Asunto(s)
Hogares para Ancianos , Humanos , Masculino , Femenino , Anciano , Proyectos Piloto , Anciano de 80 o más Años , Ciclismo/psicología , Ciclismo/fisiología , Ejercicio Físico/psicología , Ejercicio Físico/fisiología , Evaluación de Programas y Proyectos de Salud , Terapia por Ejercicio/métodos , Terapia por Ejercicio/psicología
9.
PLoS One ; 19(5): e0301293, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38743677

RESUMEN

Bicycle safety has emerged as a pressing concern within the vulnerable transportation community. Numerous studies have been conducted to identify the significant factors that contribute to the severity of cyclist injuries, yet the findings have been subject to uncertainty due to unobserved heterogeneity and class imbalance. This research aims to address these issues by developing a model to examine the impact of key factors on cyclist injury severity, accounting for data heterogeneity and imbalance. To incorporate unobserved heterogeneity, a total of 3,895 bicycle accidents were categorized into three homogeneous sub-accident clusters using Latent Class Cluster Analysis (LCA). Additionally, five over-sampling techniques were employed to mitigate the effects of data imbalance in each accident cluster category. Subsequently, Bayesian Network (BN) structure learning algorithms were utilized to construct 32 BN models after pairing the accident data from the four accident cluster types before and after sampling. The optimal BN models for each accident cluster type provided insights into the key factors associated with cyclist injury severity. The results indicate that the key factors influencing serious cyclist injuries vary heterogeneously across different accident clusters. Female cyclists, adverse weather conditions such as rain and snow, and off-peak periods were identified as key factors in several subclasses of accident clusters. Conversely, factors such as the week of the accident, characteristics of the trafficway, the season, drivers failing to yield to the right-of-way, distracted cyclists, and years of driving experience were found to be key factors in only one subcluster of accident clusters. Additionally, factors such as the time of the crash, gender of the cyclist, and weather conditions exhibit varying levels of heterogeneity across different accident clusters, and in some cases, exhibit opposing effects.


Asunto(s)
Accidentes de Tránsito , Teorema de Bayes , Ciclismo , Ciclismo/lesiones , Humanos , Femenino , Masculino , Accidentes de Tránsito/estadística & datos numéricos , Adulto , Análisis por Conglomerados , Lesiones Accidentales/epidemiología , Lesiones Accidentales/etiología , Persona de Mediana Edad , Adulto Joven , Adolescente , Factores de Riesgo
10.
PLoS One ; 19(5): e0301368, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38728323

RESUMEN

BACKGROUND: Intensive care unit (ICU)-acquired weakness (ICU-AW) is one of the most common complications of post-ICU syndrome. It is the leading cause of gait disturbance, decreased activities of daily living, and poor health-related quality of life. The early rehabilitation of critically ill patients can reduce the ICU-AW. We designed a protocol to investigate the feasibility and safety of conventional rehabilitation with additional in-bed cycling/stepping in critically ill patients. METHODS: The study is designed as a single-center, single-blind, pilot, randomized, parallel-group study. After the screening, participants are randomly allocated to two groups, stratified by mechanical ventilation status. The intervention group will be provided with exercises of in-bed cycling/stepping according to the level of consciousness, motor power, and function in addition to conventional rehabilitation. In contrast, the control group will be provided with only conventional rehabilitation. The length of intervention is from ICU admission to discharge, and interventions will be conducted for 20 minutes, a maximum of three sessions per day. RESULTS: The outcomes are the number and percentage of completed in-bed cycling/stepping sessions, the duration and percentage of in-bed cycling/stepping sessions, and the number of cessations of in-bed cycling/stepping sessions, the interval from ICU admission to the first session of in-bed cycling/stepping, the number and percentage of completed conventional rehabilitation sessions, the duration and percentage of conventional rehabilitation sessions, the number of cessations of conventional rehabilitation sessions, the number of adverse events, level of consciousness, functional mobility, muscle strength, activities of daily living, and quality of life. DISCUSSION: This study is a pilot clinical trial to investigate the feasibility and safety of conventional rehabilitation with additional in-bed cycling/stepping in critically ill patients. If the expected results are achieved in this study, the methods of ICU rehabilitation will be enriched. TRIAL REGISTRATION: clinicialtrials.gov, Clinical Trials Registration #NCT05868070.


Asunto(s)
Enfermedad Crítica , Terapia por Ejercicio , Estudios de Factibilidad , Unidades de Cuidados Intensivos , Humanos , Enfermedad Crítica/rehabilitación , Proyectos Piloto , Terapia por Ejercicio/métodos , Método Simple Ciego , Masculino , Calidad de Vida , Femenino , Adulto , Ciclismo , Persona de Mediana Edad , Actividades Cotidianas , Anciano
11.
Accid Anal Prev ; 202: 107554, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38701558

RESUMEN

BACKGROUND: Hazard perception (HP) has been argued to improve with experience, with numerous training programs having been developed in an attempt to fast track the development of this critical safety skill. To date, there has been little synthesis of these methods. OBJECTIVE: The present study sought to synthesise the literature for all road users to capture the breadth of methodologies and intervention types, and quantify their efficacy. DATA SOURCES: A systematic review of both peer reviewed and non-peer-reviewed literature was completed. A total of 57 papers were found to have met inclusion criteria. RESULTS: Research into hazard perception has focused primarily on drivers (with 42 studies), with a limited number of studies focusing on vulnerable road users, including motorcyclists (3 studies), cyclists (7 studies) and pedestrians (5 studies). Training was found to have a large significant effect on improving hazard perception skills for drivers (g = 0.78) and cyclists (g = 0.97), a moderate effect for pedestrians (g = 0.64) and small effect for motorcyclists (g = 0.42). There was considerable heterogeneity in the findings, with the efficacy of training varying as a function of the hazard perception skill being measured, the type of training enacted (active, passive or combined) and the number of sessions of training (single or multiple). Active training and single sessions were found to yield more consistent significant improvements in hazard perception. CONCLUSIONS: This study found that HP training improved HP skill across all road user groups with generally moderate to large effects identified. HP training should employ a training method that actively engages the participants in the training task. Preliminary results suggest that a single session of training may be sufficient to improve HP skill however more research is needed into the delivery of these single sessions and long-term retention. Further research is also required to determine whether improvements in early-stage skills translate to improvements in responses on the road, and the long-term retention of the skills developed through training.


Asunto(s)
Accidentes de Tránsito , Conducción de Automóvil , Humanos , Accidentes de Tránsito/prevención & control , Conducción de Automóvil/educación , Conducción de Automóvil/psicología , Motocicletas , Ciclismo , Percepción , Seguridad , Peatones
13.
Cogn Res Princ Implic ; 9(1): 32, 2024 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-38767722

RESUMEN

Drivers must respond promptly to a wide range of possible road hazards, from trucks veering into their lane to pedestrians stepping onto the road. While drivers' vision is tested at the point of licensure, visual function can degrade, and drivers may not notice how these changes impact their ability to notice and respond to events in the world in a timely fashion. To safely examine the potential consequences of visual degradation on hazard detection, we performed two experiments examining the impact of simulated optical blur on participants' viewing duration thresholds in a hazard detection task, as a proxy for eyes-on-road duration behind the wheel. Examining this question with older and younger participants, across two experiments, we found an overall increase in viewing duration thresholds under blurred conditions, such that younger and older adults were similarly impacted by blur. Critically, in both groups, we found that the increment in thresholds produced by blur was larger for non-vehicular road hazards (pedestrians, cyclists and animals) compared to vehicular road hazards (cars, trucks and buses). This work suggests that blur poses a particular problem for drivers detecting non-vehicular road users, a population considerably more vulnerable in a collision than vehicular road users. These results also highlight the importance of taking into account the type of hazard when considering the impacts of blur on road hazard detection.


Asunto(s)
Conducción de Automóvil , Humanos , Adulto , Adulto Joven , Masculino , Femenino , Anciano , Persona de Mediana Edad , Percepción Visual/fisiología , Accidentes de Tránsito , Vehículos a Motor , Ciclismo/fisiología , Adolescente
14.
PLoS One ; 19(5): e0300458, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38787863

RESUMEN

Road traffic collisions disproportionately impact Ghana and other low- and middle-income countries. This study explored road user perspectives regarding the magnitude, contributing factors, and potential solutions to road traffic collisions, injuries, and deaths. We designed a qualitative study of 24 in-depth interviews with 14 vulnerable road users (pedestrians, occupants of powered 2- and 3-wheelers, cyclists) and ten non-vulnerable road users in four high-risk areas in November 2022. We used a mixed deductive (direct content analysis) and inductive (interpretive phenomenological analysis) approach. In the direct content analysis, a priori categories based on Haddon's Matrix covered human, vehicle, socioeconomic environment, and physical environment factors influencing road traffic collisions, along with corresponding solutions. We used inductive analysis to identify emerging themes. Participants described frequent and distressing experiences with collisions, and most often reported contributing factors, implementation gaps, and potential solutions within the human (road user) level domain of Haddon's Matrix. Implementation challenges included sporadic enforcement, reliance on road users' adherence to safety laws, and the low quality of the existing infrastructure. Participants expressed that they felt neglected and ignored by road safety decision-makers. This research emphasizes the need for community input for successful road safety policies in Ghana and other low- and middle-income countries, calling for greater governmental support an action to address this public health crisis. We recommend the government collaborates with communities to adapt existing interventions including speed calming, footbridges, and police enforcement, and introduces new measures that meet local needs.


Asunto(s)
Accidentes de Tránsito , Humanos , Accidentes de Tránsito/mortalidad , Accidentes de Tránsito/prevención & control , Ghana/epidemiología , Femenino , Masculino , Adulto , Persona de Mediana Edad , Peatones/psicología , Ciclismo , Heridas y Lesiones/mortalidad , Heridas y Lesiones/epidemiología , Adulto Joven , Investigación Cualitativa , Seguridad , Gobierno , Adolescente
15.
Physiol Rep ; 12(10): e16086, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38783143

RESUMEN

Based on Mader's mathematical model, the rate of capillary blood lactate concentration (νLamax) following intense exercise is thought to reflect the maximal glycolytic rate. We aimed to investigate the reliability of important variables of Mader's model (i.e. power output, lactate accumulation, predominant phosphagen contribution time frames (tP Cr)) and resulting νLamax values derived during and after a 15-s cycling sprint. Fifty cyclists performed a 15-s all-out sprint test on a Cyclus2 ergometer three times. The first sprint test was considered a familiarization trial. Capillary blood was sampled before and every minute (for 8 min) after the sprint to determine νLamax. Test-retest analysis between T2 and T3 revealed excellent reliability for power output (Pmean and Ppeak; ICC = 0.99, 0.99), ∆La and νLamax with tPCr of 3.5 s (ICC = 0.91, 0.91). νLamax calculated with tPCr = tP peak (ICC = 0.87) and tP Cr = tPpeak-3.5% (ICC = 0.79) revealed good reliability. tPpeak and tPpeak-3.5% revealed only poor and moderate reliability (ICC = 0.41, 0.52). Power output and ∆La are reliable parameters in the context of this test. Depending on tPCr, reliability of νLamax varies considerably with tP Cr of 3.5 s showing excellent reliability. We recommend standardization of this type of testing especially tP Cr.


Asunto(s)
Ciclismo , Ácido Láctico , Humanos , Ciclismo/fisiología , Masculino , Adulto , Ácido Láctico/sangre , Capilares/fisiología , Capilares/metabolismo , Reproducibilidad de los Resultados , Prueba de Esfuerzo/métodos , Adulto Joven , Femenino
16.
J Biomech ; 169: 112121, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38733816

RESUMEN

Models of physical phenomena can be developed using two distinct approaches: using expert knowledge of the underlying physical principles or using experimental data to train a neural network. Here, our aim was to better understand the advantages and disadvantages of these two approaches. We chose to model cycling power because the physical principles are already well understood. Nine participants followed changes in cycling cadence transmitted through a metronome via earphones and we measured their cadence and power. We then developed and trained a physics-based model and a simple neural network model, where both models had cadence, derivative of cadence, and gear ratio as input, and power as output. We found no significant differences in the prediction performance between the models. Both models had good prediction accuracy despite using less input variables than traditional models and using more challenging prediction conditions by enforcing rapid speed changes during cycling. The advantages of the neural network model were that, for similar performance, it did not require an understanding of the underlying principles of cycling nor did it require measurements of fixed parameters such as system weight or wheel size. These same features also give the physics-based model the advantage of interpretability, which can be important when scientists want to better understand the process being modelled.


Asunto(s)
Ciclismo , Redes Neurales de la Computación , Humanos , Ciclismo/fisiología , Masculino , Adulto , Modelos Biológicos , Femenino , Adulto Joven , Fenómenos Biomecánicos
17.
J Trace Elem Med Biol ; 84: 127470, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38744035

RESUMEN

BACKGROUND: Nutritional strategies with iron supplementation have been shown to be effective in preventing the decline of blood biochemical parameters and sports performance. The aim of the study was to describe biochemical iron metabolism parameters in association with iron supplementation and HFE and AMPD1 polymorphisms in a Union Cycliste Internationale (UCI) World Tour cycling team to evaluate performance during a whole season METHODS: Twenty-eight professional men cyclists took part in this longitudinal observational pilot study. AMPD1 c.34 C>T (rs17602729) and HFE c.187 C>G (rs1799945) polymorphisms were genotyped using Single Nucleotide Primer Extension (SNPE). All the professional cyclists took oral iron supplementation throughout the season. Four complete blood analyses were carried out corresponding to UCI controls in January (1st), April (2nd), June (3rd) and October (4th). Data on participation in three-week Grand Tours, kms of competition and wins were analyzed. RESULTS: In performance, especially in wins, there was a significant effect in HFE on biochemical hemoglobin (F = 4.255; p = 0.021) and biochemical hematocrit (F = 5.335; p = 0.009) and a hematocrit biochemical × genotype interaction (F = 3.418; p = 0.041), with higher values in professional cyclist with GC genotype. In AMPD1 there were significant effects in the biochemical iron x genotype interaction in three-week Grand Tours (F = 3.874; p = 0.029) and wins (F = 3.930; p = 0.028) CONCLUSIONS: Blood biochemical iron metabolism parameters could be related to performance in the season due to increasing hemoglobin and hematocrit concentration under iron supplementation, associated with winning in the professional cyclists with GC genotype of the HFE polymorphism.


Asunto(s)
AMP Desaminasa , Suplementos Dietéticos , Proteína de la Hemocromatosis , Hierro , Humanos , Masculino , Proteína de la Hemocromatosis/genética , Proyectos Piloto , Hierro/metabolismo , Hierro/sangre , Adulto , AMP Desaminasa/genética , Ciclismo , Polimorfismo de Nucleótido Simple/genética , Adulto Joven , Genotipo
18.
Nutrients ; 16(10)2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38794731

RESUMEN

Relevant properties of the somatotype as important indicators can be associated with the body composition characteristics as well as both metabolic and bio-mechanical efficiency of athletes in the sport concerned. The primary aim of this single cross-sectional study was to determine the somatotype profiles in association with body composition and nutritional profiles among Lithuanian elite athletes (n = 189) involved in water, cycling and combat sports. The body composition along with the somatotype profiles and the nutritional status of athletes were evaluated using a battery of multiple frequency (5, 50, 250, 550, and 1000 kHz) bioelectrical impedance analysis (BIA) and a 3-day food record analysis. In terms of the prediction for athletes to be classified as endomorphs, mesomorphs or ectomorphs, the linear discriminant analysis was conducted to assess the grouping of samples. Both the multiple linear regression and multivariate logistic regression statistical analyses were performed to explore the associations between the independent and dependent variables. The central tendency values for the somatotype components of endomorphy, mesomorphy and ectomorphy in athletes playing water, cycling and combat sports were 4.3-4.9-3.4, 4.3-4.8-3.4 and 4.5-5.5-2.9, respectively. The central mesomorph somatotype with a trend towards endomorphy was dominant and varied according to a high muscle-to-fat ratio in elite athletes. Significant (p ≤ 0.001) positive associations between both endomorphy and mesomorphy values and higher body fat percentage as well as lower and upper limb muscle mass were identified. The lower levels of trunk muscle mass were related to athletes' endomorphy and mesomorphy, too. Furthermore, in the athletes' sample under analysis, high-level mesomorphs were prone to consume low-carbohydrate (adjusted odd ratio (AOR) 0.5, 95% confidence interval (CI) 0.2; 0.9) and high-protein diets (AOR 2.5, 95% CI 1.1; 5.5). Contrastingly, the elite athletes with a higher expression of endomorphy were on high-carbohydrate (AOR 5.4, 95% CI 1.1; 8.3) and high-fat diets (AOR 4.6, 95% CI 1.5; 7.1) along with insufficient protein diet (AOR 0.3, 95% CI 0.1; 0.9). Finally, whilst nutrition goals as a mediator can play a significant role in undergoing the maintenance of balance between the optimal body composition for athletic performance and the development of an ecto-mesomorphic somatotype, the elite athletes with higher levels of endomorphy value should be aware of lowering the body fat percentage coupled with dietary fat reduction and higher protein intakes. The findings obtained from the study may serve as an antecedent for a more targeted management of the elite athletes' training process. Somatotyping as an additional assessment method can be successfully deployed in choosing correct coaching techniques, contributing to talent recognition processes or identifying reference morphometric parameters in elite athletes competing in water, cycling and combat sports.


Asunto(s)
Atletas , Composición Corporal , Estado Nutricional , Somatotipos , Deportes Acuáticos , Humanos , Somatotipos/fisiología , Masculino , Estudios Transversales , Adulto Joven , Adulto , Deportes Acuáticos/fisiología , Femenino , Impedancia Eléctrica , Ciclismo/fisiología , Nutrientes , Lituania , Adolescente , Artes Marciales/fisiología , Dieta/métodos , Rendimiento Atlético/fisiología
19.
J Strength Cond Res ; 38(6): e280-e287, 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38595296

RESUMEN

ABSTRACT: Yamashita, Y and Umemura, Y. Effect of high-intensity with short-duration re-warm up on subsequent performance in a cold environment. J Strength Cond Res 38(6): e280-e287, 2024-The aim of this study was to investigate the effect of high-intensity, short-duration re-warm-up (RW) during half time (HT) on subsequent performance in a cold environment. Eleven male subjects (age, 21 ± 2 years; height, 172.4 ± 4.5 cm; body mass, 65.6 ± 7.1 kg; V̇ o2 max, 47.5 ± 4.8 ml·kg -1 ·min -1 ) performed 2 experimental trials comprising 40 minutes of intermittent cycling exercise, which consisted of 15-second rest, 25-second unloading cycling, 10-second high-intensity cycling, and 70-second moderate-intensity cycling as the first half. In the second half, a cycling intermittent-sprint protocol (CISP) was performed, separated by a 15-minute HT period in cold conditions (5 °C, 50% relative humidity). Two experimental trials were included in a random order: (a) approximately 1 minute of high-intensity, short-duration RW (3 sets of 3-second maximal pedaling [body weight × 0.075 kp]) trial high-intensity intermittent cycling trials (HII); (b) 15 minutes of seated rest trial (CON). Cycling intermittent-sprint protocol consisted of 10 sets of a 2-minute exercise protocol, and each set consisted of 10-second rest, 5-second maximal pedaling (body weight × 0.075 kp), and 105-second active recovery at 50% maximum oxygen uptake (V̇ o2 max). Peak power output of 5-second maximal pedaling during CISP was higher in HII trials than in CON trials (HII: 807 ± 81 W, CON: 791 ± 78 W, p < 0.05). There was no significant difference in rectal temperature between trial types ( p > 0.05). These results suggest that high-intensity, short-duration RW may be a useful HT strategy for improving subsequent performance in cold environments.


Asunto(s)
Rendimiento Atlético , Ciclismo , Frío , Ejercicio de Calentamiento , Humanos , Masculino , Adulto Joven , Rendimiento Atlético/fisiología , Ejercicio de Calentamiento/fisiología , Ciclismo/fisiología , Consumo de Oxígeno/fisiología , Frecuencia Cardíaca/fisiología , Adulto , Factores de Tiempo , Entrenamiento de Intervalos de Alta Intensidad/métodos
20.
Forensic Sci Int ; 359: 112027, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38677158

RESUMEN

Bicycles are employed as means of transportation across various age groups, from young students to the elderly, for work, education, health, and leisure trips. Despite not achieving high speeds, bicyclists remain vulnerable to severe and even fatal injuries when they are involved in traffic accidents. Although the rising awareness of ecological issues and traffic law enforcement mean that cyclists are increasingly susceptible to road traffic crashes and injuries. Injuries resulting from a traffic accident involving cyclists can show distinct and specific characteristics depending on the manner of occurrence. The aim of this study is to provide a systematic review of the literature on injuries sustained in cyclists involved in road accidents describing and analysing elements useful for forensic assessment. The literature search was performed using PubMed, Scopus, and Web of Science from January 1970 to March 2023. Eligible studies have investigated issues of interest to forensic medicine about traffic accidents involving bicycles. A total of 128 studies satisfied the inclusion criteria and were categorized and analyzed according to the anatomical regions of the body affected (head, neck, thoraco-abdominal, and limb injuries), and the assessment of lesions in reconstruction of the bicycle accident was examined and discussed. This review highlights that injuries resulting from a traffic accident involving cyclists can show distinct and specific characteristics depending on the manner of occurrence and the energy levels involved in the crash. The assessment of injuries offers valuable insights that integrated with circumstantial and engineering data perform the reconstruction of accident dynamics.


Asunto(s)
Accidentes de Tránsito , Ciclismo , Humanos , Ciclismo/lesiones , Heridas y Lesiones/epidemiología
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