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1.
Sci Rep ; 12(1): 18354, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-36319680

RESUMO

Bicyclists still account for the majority of child deaths in traffic accidents, despite a gradual decrease in incidence. Therefore, we investigated factors associated with child and adult bicyclist fatalities. In this retrospective study, we used data from a national hospital-based database, the Japan Trauma Data Bank. Data from 2004 to 2019 were obtained for child cyclists (5-18 years; n = 4832) and adult cyclists (26-45 years; n = 3449). In each age group, physiological variables, outcomes, and injury severity were compared between fatal and non-fatal cases. Multivariate logistic regression was performed to determine factors associated with fatality. In adults, fatality was associated with lower values for body temperature, Glasgow Coma Scale score, and Abbreviated Injury Scale (AIS) score for the neck and upper extremities, and with higher values for respiratory rate, heart rate, focused assessment with sonography for trauma positivity rate, and AIS scores for the head, chest, and abdomen. In children, fatality was associated with lower values for body temperature and the Glasgow Coma Scale score, and with higher values for the AIS chest score. These findings point to factors associated with bicyclist fatalities and may help in the development of effective strategies to reduce these fatalities.


Assuntos
Acidentes de Trânsito , Ciclismo , Adulto , Criança , Humanos , Estudos Retrospectivos , Escala Resumida de Ferimentos , Escala de Coma de Glasgow
2.
Cad Saude Publica ; 38(10): e00057222, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36449841

RESUMO

This time-series study examined a 10-year historical series of the physical activity prevalence for leisure and transportation in the Brazilian adult population. Information from 512,969 adults interviewed from the Vigitel between 2010 and 2019 was analyzed. Individuals who reported practicing at least 150 minutes/week of moderate-intensity physical activity or at least 75 minutes/week of vigorous-intensity physical activity were considered active during leisure time. Individuals who reported walking or cycling to/from work, course, or school at least 30 minutes/day, equivalent to at least 150 minutes/week of moderate-intensity physical activity, were considered active during transportation. The prevalence of physical activity for leisure and transportation was calculated annually and stratified by sex, age group, schooling, and race/skin color. The segmented regression model was applied to analyze the time series. Annual percent change and average annual percent change were calculated. Over time, the prevalence of physical activity for leisure increased, and the prevalence of physical activity for transportation decreased. The highest prevalence of physical activity for leisure was observed among males, young individuals, and those with high education. Older adults, those with high education, and white people presented the lowest prevalence of active transport. Policymakers should propose strategies that encourage and facilitate physical activity for leisure in women, individuals aged ≥ 35 years, and those with less education (< 12 years), and physical activity for transportation among older adults (≥ 60 years), those with high education (≥ 12 years), and white people.


Assuntos
Exercício Físico , Meios de Transporte , Masculino , Humanos , Feminino , Idoso , Brasil , Ciclismo , Escolaridade
3.
Artigo em Inglês | MEDLINE | ID: mdl-36361027

RESUMO

The literature has offered much evidence regarding associations between the built environment (BE) and commuting behavior. However, most prior studies are conducted based on cross-sectional samples from developed countries, and little is known about the longitudinal link between BE and commuting behavior. Based on two rounds of survey data from China, this study examines relationships of BE with commuting mode choice from both cross-sectional and longitudinal perspectives. The effects of life-cycle events are considered within a unified framework. Results of the longitudinal examination of BE and commuting mode shift largely support the cross-sectional analysis. Specifically, promoting more balanced land use and improving residential density are important for car use reductions and active travel initiatives. Meanwhile, more balanced land use improves the probability of commuting by motorcycle and electric bike, but reduces the probability of commuting by public transit. This study also highlights the remarkable role played by life-cycle events in affecting commuting mode shifts.


Assuntos
Meios de Transporte , Caminhada , Estudos Transversais , Ambiente Construído , Ciclismo
4.
Eur J Cancer Care (Engl) ; 31(6): e13751, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36382401

RESUMO

OBJECTIVE: The purpose of this study was to explore how men with advanced lung cancer form perceptions of their illness in everyday life and how this influences perceptions about rehabilitation. METHODS: Constructivist grounded theory principles guided the collection and analysis of data from in-depth interviews with 10 men with advanced lung cancer. RESULTS: The findings show that the men's illness perception was fluid, contextual and formed by interrelated factors. Engaging in daily activities and maintaining everyday life was a strong influence on their illness perception. CONCLUSION: In order to make rehabilitation relevant to men with lung cancer, consideration should be given to how the men's everyday lives may be incorporated into the service provision.


Assuntos
Percepção de Forma , Neoplasias Pulmonares , Masculino , Humanos , Ciclismo , Teoria Fundamentada
6.
Artigo em Inglês | MEDLINE | ID: mdl-36429918

RESUMO

OBJECTIVES: The purpose of our study is to retrospectively analyze and compare the patterns of maxillofacial-related injuries among rides of electric-powered bikes (E-bikes) and electric-powered scooters (E-scooters), the associated risk factors, and the required treatment. MATERIALS AND METHODS: The medical files of all riders presenting to the emergency department at the Tel Aviv Sourasky Medical Center between 2019 and 2020 with oral- and maxillofacial-related injuries due to E-bike and E-scooter accidents were reviewed. RESULTS: A total of 320 riders sustained oral- and maxillofacial-related injuries due to trauma involving E-bikes and E-scooters during the study period. E-scooter riders were involved in 238 accidents (74.5%) while E-bike riders accounted for the remaining 82 accidents (27.5%). Eighty-four out of 320 riders (26.25%) were hospitalized and required surgical interventions. Most of the 232 riders (72.5%) who reported not wearing a protective helmet during the index accident were E-scooter riders. In addition, 39 riders (18.66%) were riding either of these electric-powered vehicles under the influence of alcohol. CONCLUSIONS: E-bike riders are more likely to sustain a maxillofacial fracture than E-scooter riders. Not wearing a protective helmet and riding under the influence of alcohol are major risk factors for maxillofacial injuries.


Assuntos
Ciclismo , Traumatismos Maxilofaciais , Humanos , Ciclismo/lesões , Estudos Retrospectivos , Dispositivos de Proteção da Cabeça , Traumatismos Maxilofaciais/epidemiologia , Traumatismos Maxilofaciais/etiologia , Acidentes , Etanol
7.
Int J Sports Physiol Perform ; 17(12): 1664-1671, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36343622

RESUMO

PURPOSE: To critically appraise the utility of heart rate (HR) and power output (PO) to predict metabolic rate (MR) and oxygen consumption (V˙O2) during variable-intensity roller skiing and cycling. METHODS: National-level cyclists (n = 8) and cross-country skiers (n = 9) completed a preliminary session to determine V˙O2max, and a variable-intensity protocol with 3 high-intensity stages at 90% V˙O2max for 3 minutes interspersed with 3 moderate-intensity stages at 70% V˙O2max for 6 minutes. Cardiorespiratory measures were recorded throughout. Linear HR-MR, HR-V˙O2, PO-MR, and PO-V˙O2 regressions were computed from the preliminary session, individually, for all athletes and used to predict MR and V˙O2 from both HR and PO, separately, during the variable-intensity protocol. Mean differences with 95% limits of agreement (LOA) between measured and predicted MR and V˙O2 were calculated. RESULTS: MR and V˙O2 estimated from HR displayed a mean bias close to zero but wide LOA. HR overestimated MR and V˙O2 during moderate intensity but underestimated MR and V˙O2 during high intensity, for both roller skiing and cycling. MR and V˙O2 estimated from PO were more consistent across the experimental trial, displaying a mean bias farther from zero but with tighter LOA. CONCLUSIONS: This study has demonstrated that HR has limited utility to predict metabolic intensity during variable-intensity roller skiing and cycling because of wide LOA. On the other hand, metabolic intensity predicted from PO had tighter LOA, suggesting better consistency. PO might provide a better prediction of metabolic intensity compared with HR, particularly when longer-duration steps are performed during preliminary testing.


Assuntos
Esqui , Humanos , Esqui/fisiologia , Frequência Cardíaca/fisiologia , Ciclismo/fisiologia , Consumo de Oxigênio/fisiologia , Atletas , Teste de Esforço/métodos
8.
Sensors (Basel) ; 22(21)2022 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-36365913

RESUMO

In recent years, cities are experiencing changes in the ways of moving around, increasing the use of micromobility vehicles. Bicycles are the most widespread transport mode and, therefore, cyclists' behaviour, safety, and comfort have been widely studied. However, the use of other personal mobility vehicles is increasing, especially e-scooters, and related studies are scarce. This paper proposes a low-cost open-source data acquisition system to be installed on an e-scooter. This system is based on Raspberry Pi and allows collecting speed, acceleration, and position of the e-scooter, the lateral clearance during meeting and overtaking manoeuvres, and the vibrations experienced by the micromobility users when riding on a bike lane. The system has been evaluated and tested on a bike lane segment to ensure the accuracy and reliability of the collected data. As a result, the use of the proposed system allows highway engineers and urban mobility planners to analyse the behaviour, safety, and comfort of the users of e-scooters. Additionally, the system can be easily adapted to another micromobility vehicle and used to assess pavement condition and micromobility users' riding comfort on a cycling network when the budget is limited.


Assuntos
Aceleração , Ciclismo , Reprodutibilidade dos Testes , Coleta de Dados , Acidentes de Trânsito/prevenção & controle
9.
Sensors (Basel) ; 22(21)2022 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-36366195

RESUMO

In recent years, with the diversification of people's modes of transportation, a large amount of traffic data is generated when people travel every day, and this data can help transportation mode detection to be of great use in a variety of applications. Although transportation mode detection has been investigated, there are still challenges in terms of accuracy and robustness. This paper presents a novel transportation mode detection algorithm, DFTrans, which is based on Temporal Block and Attention Block. Low- and high-frequency components of traffic sequences are obtained using discrete wavelet transforms. A two-channel encoder is carefully designed to accurately capture the temporal and spatial correlation between low- and high-frequency components in both long- and short-term patterns. With the Temporal Block, the inductive bias of the CNN is introduced at high frequencies to improve generalization performance. At the same time, the network is generated with the same length as the input, ensuring a long effective history. Low frequencies are passed through Attention Block, which has fewer parameters to capture the global focus and solves the problem that RNNs cannot be computed in parallel. After fusing the output of the feature by Temporal Block and Attention Block, the classification results are output by MLP. Extensive experimental results show that the DFTrans algorithm achieves macro F1 scores of 86.34% on the real-world SHL dataset and 87.64% on the HTC dataset. Our model can better identify eight modes of transportation, including stationary, walking, running, cycling, bus, car, underground, and train, and has better performance in transportation mode detection than other baseline algorithms.


Assuntos
Ciclismo , Meios de Transporte , Humanos , Meios de Transporte/métodos , Caminhada , Viagem , Algoritmos
10.
Artigo em Inglês | MEDLINE | ID: mdl-36360761

RESUMO

Previous research on the role of school travel in children's well-being (WB) has paid little attention to developing countries. Using national survey data across China, this study examines how children's psychological well-being (PWB) and academic performance differ across commute duration and mode among urban, rural, and urban fringe areas. Our findings show that commute times are significantly negatively associated with children's PWB and academic achievements, and this correlation varies across areas. Children living in the urban fringe have the longest average one-way commuting time (18.6 min), but they have a better acceptance of longer commuting duration, whereas commuting time is more influential in the city center and rural areas. Regarding travel mode, walking to school is positively associated with PWB in the center area, while bicycles and public transport positively affect the rural student scores. Results from quantile regression show that students on the lower quantiles of the conditional distribution of PWB tend to suffer more than the others when commuting time increases; students with middle scores respond similarly to marginal changes in commuting time. Recommendations for urban planners and policymakers to enhance child WB include fostering school-home balance, improving public transit services, and investing in pedestrian and bicycle infrastructure for those vulnerable groups.


Assuntos
Sucesso Acadêmico , Criança , Humanos , Ciclismo , Instituições Acadêmicas , Meios de Transporte , Caminhada , China
11.
Artigo em Inglês | MEDLINE | ID: mdl-36429672

RESUMO

This study evaluated the acute effects of sprint interval training and chronic effects of polarized training on choice reaction time in cyclists. Twenty-six mountain bike cyclists participated in the study and were divided into experimental (E) and control (C) groups. The cyclists trained for 9-weeks and performed five training sessions each week. Types of training sessions: (1) sprint interval training (SIT) which consisted of 8-16, 30 s repetitions at maximal intensity, (2) high-intensity interval training (HIIT) included 5 to 7, 5-min efforts at an intensity of 85-95% maximal aerobic power (Pmax), and (3) endurance training (ET) performed at an intensity of 55-60% Pmax, lasting 120--180 min. In each week the cyclists performed: in group E a polarized training program, which included 2 × SIT, 1 × HIIT and 2 × ET, while in group C 2 × HIIT and 3 × ET. Before (acute effects) and after the 9-week training period (chronic effects) participants performed laboratory sprint interval testing protocol (SITP), which consisted of 12 maximal repetitions lasting 30 s. During SITP maximal and mean anaerobic power, as well as lactate ion concentration and blood pH were measured. Choice reaction time (RT) was measured 4-times: before and immediately after the SITP test-before and after the 9-week training period. Evaluated the average choice RT, minimal choice RT (shortest reaction), maximal choice RT (longest reaction), and the number of incorrect reactions. Before the training period as acute effects of SITP, it was observed: a shorter average choice RT (F = 13.61; p = 0.001; η2 = 0.362) and maximal choice RT (F = 4.71; p = 0.040; η2 = 0.164), and a decrease the number of incorrect reactions (F = 53.72; p = 0.000; η2 = 0.691), for E and C groups. After the 9-week training period, chronic effects showed that choice RT did not change in any of the cyclists' groups. Only in the E group after the polarized training period, the number of incorrect reactions decreased (F = 49.03; p = 0.000; η2 = 0.671), average anaerobic power increased (F = 8.70; p = 0.007; η2 = 0.274) and blood pH decreased (F = 27.20; p = 0.000; η2 = 0.531), compared to the value before the training period. In conclusion, a shorter choice RT and a decrease in the number of incorrect reactions as acute effects of SITP, and a decrease in the number of incorrect reactions and higher average power as chronic effects of the polarized training program are beneficial for mountain bike cyclists.


Assuntos
Treino Aeróbico , Treinamento Intervalado de Alta Intensidade , Humanos , Treinamento Intervalado de Alta Intensidade/métodos , Ciclismo , Tempo de Reação , Consumo de Oxigênio
12.
Artigo em Inglês | MEDLINE | ID: mdl-36429693

RESUMO

This study aims to estimate the avoided mortalities and morbidities and related economic impacts due to adopting the nonmotorized transportation (NMT) policy in Delhi, India. To this aim, an integrated quantitative assessment framework is developed to estimate the expected environmental, health, and economic co-benefits from replacing personal motorized transport with NMT in Delhi, taking into account the inhabitants' willingness to use NMT (walking and cycling) mode. The willingness to accept NMT is estimated by conducting a cross-sectional survey in Delhi, which is further used to estimate the expected health benefits from both increased physical activity and near-roadway-avoided PM2.5 exposure in selected traffic areas in 11 major districts in Delhi. The value of a statistical life (VSL) and cost of illness methods are used to calculate the economic benefits of the avoided mortalities and morbidities from NMT in Delhi. The willingness assessment indicates that the average per capita time spent walking and cycling in Delhi is 11.054 and 2.255 min, respectively. The results from the application of the NMT in Delhi show the annual reduction in CO2 and PM2.5 to be 121.5 kilotons and 138.9 tons, respectively. The model estimates the expected co-benefits from increased physical activities and reduced PM2.5 exposure at 17,529 avoided cases of mortality with an associated savings of about USD 4870 million in Delhi.


Assuntos
Ciclismo , Meios de Transporte , Estudos Transversais , Meios de Transporte/métodos , Caminhada , Material Particulado/análise
13.
PLoS One ; 17(11): e0270093, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36395344

RESUMO

INTRODUCTION: A typical heat acclimation (HA) protocol takes 5-7 d of 60-90 minutes of heat exposure. Identifying the minimum dose of HA required to elicit a heat adapted phenotype could reduce financial constraints on participants and aid in the tapering phase for competition in hot countries. Therefore, the aim of this study was to investigate a 4 d HA regimen on physical performance. METHODS: Twelve moderately trained males were heat acclimated using controlled hyperthermia (Tre>38.5°C), with no fluid intake for 90 min on 4 consecutive days, with a heat stress test (HST) being completed one week prior to (HST2), and within one-week post (HST3) HA. Eleven completed the control study of HST1 versus HST2, one week apart with no intervention. Heat stress tests comprised of cycling for 90 min @ 40% Peak Power Output (PPO); 35°C; 60%RH followed by 10 minutes of passive recovery before an incremental test to exhaustion. Physical performance outcomes time to exhaustion (TTE), PPO, end rectal temperature (Tre END), and heart rate (HREND) was measured during the incremental test to exhaustion. RESULTS: Physiological markers indicated no significant changes in the heat; however descriptive statistics indicated mean resting Tre lowered 0.24°C (-0.54 to 0.07°C; d = 2.35: very large) and end-exercise lowered by 0.32°C (-0.81 to 0.16; d = 2.39: very large). There were significant improvements across multiple timepoints following HA in perceptual measures; Rate of perceived exertion (RPE), Thermal Sensation (TS), and Thermal Comfort (TC) (P<0.05). Mean TTE in the HST increased by 142 s (323±333 to 465±235s; P = 0.04) and mean PPO by 76W (137±128 to 213±77 W; P = 0.03). CONCLUSION: Short-term isothermic HA (4 d) was effective in enhancing performance capacity in hot and humid conditions. Regardless of the level of physiological adaptations, behavioural adaptations were sufficient to elicit improved performance and thermotolerance in hot conditions. Additional exposures may be requisite to ensure physiological adaptation.


Assuntos
Transtornos de Estresse por Calor , Termotolerância , Masculino , Humanos , Aclimatação/fisiologia , Ciclismo/fisiologia , Desempenho Físico Funcional
14.
Int J Sports Physiol Perform ; 17(12): 1756-1759, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36370696

RESUMO

OBJECTIVE: To determine whether the altitude of birth/childhood influences the values in peak power output (PPO) and estimated maximum oxygen uptake (estVO2max) in male Colombian road cyclists of different performance levels. This study also aimed to determine whether cyclists born at high altitudes tend to be more successful. METHODS: Eighty riders aged between 17 and 22 years of 3 performance levels (U23 world-class level, WC, n = 8; U23 national level, N23, n = 41; junior national level, J, n = 31) and 3 altitude levels (<800 m, low; 800-2000 m, moderate; >2000 m, high) performed an ergocycle maximal incremental test to exhaustion at an altitude of 2570 m. RESULTS: Altogether, while cyclists born at an altitude >2000 m represented ∼50% of the analyzed sample, there was a significantly higher proportion (84%) of these cyclists who had participated as professionals in a Grand Tour (χ2[1, N = 80] = 4.58, P < .05). Riders of the low group had lower values of PPO and estVO2max than cyclists of moderate and high altitudes, while no differences were noted between moderate- and high-altitude groups. In N23, PPO and estVO2max were lower in the low- than in the moderate-altitude group, while in the J cyclists, PPO and estVO2max were lower in the low-altitude compared with both moderate- and high-altitude groups. DISCUSSION: Among the cyclists tested at altitude in junior and U23, there is an overrepresentation of individuals who reached an elite level and were born at a high altitude (>2000 m). As no clear differences were observed between moderate- and high-altitude cyclists, the higher prevalence of elite cyclists in the latter group may originate from various-still unclear-mechanisms.


Assuntos
Altitude , Consumo de Oxigênio , Masculino , Humanos , Criança , Adolescente , Adulto Jovem , Adulto , Ciclismo , Colômbia , Oxigênio
15.
J Sports Sci ; 40(17): 1912-1918, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36263443

RESUMO

This study sought to detail and compare the in-ride nutritional practices of a group of professional cyclists with type 1 diabetes (T1D) under training and racing conditions. We observed seven male professional road cyclists with T1D (Age: 28 ± 4 years, HbA1c: 6.4 ± 0.4% [46 ± 4 mmol.mol-1], VO2max: 73.9 ± 4.3 ml.kg -1.min-1) during pre-season training and during a Union Cycliste Internationale multi-stage road cycling race (Tour of Slovenia). In-ride nutritional, interstitial glucose, and performance variables were quantified and compared between the two events.    The in-ride energy intake was similar between training and racing conditions     (p = 0.909), with carbohydrates being the major source of fuel in both events during exercise at a rate of 41.9 ± 6.8 g.h-1 and 45.4 ± 15.5 g.h-1 (p = 0.548), respectively. Protein consumption was higher during training (2.6 ± 0.6 g.h-1) than race rides (1.9 ± 0.9 g.h-1; p = 0.051).   A similar amount of time was spent within the euglycaemic range (≥70-≤180 mg.dL-1): training 77.1 ± 32.8% vs racing 73.4 ± 3.9%; p = 0.818. These data provide new information on the in-ride nutritional intake in professional cyclists with T1D during different stages of the competitive season.


Assuntos
Ciclismo , Diabetes Mellitus Tipo 1 , Humanos , Masculino , Adulto Jovem , Adulto , Carboidratos da Dieta , Ingestão de Alimentos , Proteínas na Dieta , Glucose
16.
Int J Behav Nutr Phys Act ; 19(1): 132, 2022 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-36195957

RESUMO

BACKGROUND: There are hundreds of bikeshare programs worldwide, yet few health-related evaluations have been conducted. We enrolled a cohort of new bikeshare members in Philadelphia (Pennsylvania, USA) to assess whether within-person moderate and vigorous physical activity (MVPA) increased with higher use of the program and whether effects differed for vulnerable sub-groups. METHODS: During 2015-2018, 1031 new members completed baseline and one-year follow-up online surveys regarding their personal characteristics and past 7-day MVPA minutes per week (minutes per week with- and without walking). Participants were linked to their bikeshare trips to objectively assess program use. Negative binomial (for continuous outcomes) and multinomial (for categorical outcomes) regression adjusted for person characteristics (socio-demographics, health), weather, biking-infrastructure, and baseline biking. RESULTS: Participant median age was 30, 25% were of Black or Latino race/ethnicity, and 30% were socioeconomically disadvantaged. By follow-up, personal bike ownership increased and 75% used bikeshare, although most used it infrequently. Per 10 day change in past year (PY) bikeshare use, non-walking MVPA min/wk increased 3% (roughly 6 min/wk, P < 0.014). More days of bikeshare was also associated with change from inactive to more active (odds ratio for ≥ 15 days in PY vs. no bikeshare use 1.80, CI 1.05-3.09, P < 0.03). Results were consistent across vulnerable sub-groups. In general, impacts on MVPA were similar when exposure was personal bike or bikeshare. CONCLUSIONS: Bikeshare facilitated increases in cycling, slightly increased non-walking MVPA, and showed potential for activating inactive adults; however, for larger program impact, members will need to use it more frequently.


Assuntos
Ciclismo , Exercício Físico , Adulto , Estudos de Coortes , Humanos , Inquéritos e Questionários , Tempo (Meteorologia)
17.
Artigo em Inglês | MEDLINE | ID: mdl-36293626

RESUMO

Supporting older people's use of sustainable transport is important for both population health and sustainable development, especially in the context of global population ageing. This systematic review identifies individual and environmental factors that influence older people's sustainable transport use and synthesises findings using a framework approach. Factors influencing older people's walking (n = 10 studies), bus use (n = 11), community transport use (n = 1), bicycling (n = 1), and e-bicycling (n = 1) were found to be physical, geographical, facility-based, economic, time-based, fear-based, space-based, information-based, or interpersonal. Many factors were common across transport modes. One reason for this is that environmental features designed to facilitate the use of one particular transport mode also influenced the use of other modes (e.g., bus shelters influence not only bus use but also walking as they provide pedestrian seating). Thus, environments need to be considered from the perspective of multiple, different types of road users. Another reason is that many factors related to the ways individuals experienced their environment (e.g., finding information guiding behaviour in public spaces to be unclear), regardless of any specific transport mode. This review highlights the important need for greater cross-sectoral action and input from older people.


Assuntos
Pedestres , Humanos , Idoso , Ciclismo , Caminhada , Desenvolvimento Sustentável , Meio Ambiente , Meios de Transporte
18.
Nat Commun ; 13(1): 6420, 2022 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-36307413

RESUMO

Orange Carotenoid protein (OCP) is the only known photoreceptor which uses carotenoid for its activation. It is found exclusively in cyanobacteria, where it functions to control light-harvesting of the photosynthetic machinery. However, the photochemical reactions and structural dynamics of this unique photosensing process are not yet resolved. We present time-resolved crystal structures at second-to-minute delays under bright illumination, capturing the early photoproduct and structures of the subsequent reaction intermediates. The first stable photoproduct shows concerted isomerization of C9'-C8' and C7'-C6' single bonds in the bicycle-pedal (s-BP) manner and structural changes in the N-terminal domain with minute timescale kinetics. These are followed by a thermally-driven recovery of the s-BP isomer to the dark state carotenoid configuration. Structural changes propagate to the C-terminal domain, resulting, at later time, in the H-bond rupture of the carotenoid keto group with protein residues. Solution FTIR and UV/Vis spectroscopy support the single bond isomerization of the carotenoid in the s-BP manner and subsequent thermal structural reactions as the basis of OCP photoreception.


Assuntos
Proteínas de Bactérias , Ciclismo , Isomerismo , Proteínas de Bactérias/metabolismo , Carotenoides/metabolismo , Luz
19.
Artigo em Inglês | MEDLINE | ID: mdl-36231510

RESUMO

(1) Background: The aim of this study was to assess the impact of multi-strain probiotic supplementation on the physical capacity and selected health indicators related to the exercise capacity of competitive road cyclists such as body composition, markers of intestinal permeability, pro- and anti-inflammatory markers, and anti-/pro-oxidant potential. (2) Methods: The group comprised 26 competitive road cyclists aged between 18 and 26. The study was a 4-month double-blind, random-assignment, parallel-group, and placebo-controlled trial. The measurements of physical capacity in the exercise tests of the anaerobic Wingate test (the level of total work volume, maximal anaerobic power, average power per revolution, mean time to achieve maximal anaerobic power, and time to maintain maximal anaerobic power) and the aerobic test using a cycle ergometer (maximum oxygen uptake, exercise duration, maximum load power, and maximal heart rate) were repeated after one, three, and four months. (3) Results: The probiotic supplementation resulted in increased levels of the relative magnitude of maximal oxygen uptake (65.28 vs. 69.18), the duration of training until failure (14.35 vs. 15.65), the load on the ergometer (5.11 vs. 5.36), and the degree of decrease in heart rate (193.3 vs. 188.6) together with a feeling of less discomfort during the exercise test (Borg scale) (19.38 vs. 18.43), confirming the beneficial effect of probiotics on the cyclists' aerobic capacity during exercise. The probiotic supplementation produces no effects on the anaerobic capacity and body composition of the athletes, except for an observed increase in muscle mass. The concentration of zonulin in the stool mass decreased as a result of the probiotic therapy (81.2 vs. 25.21), and α1-atitrypsin was maintained at a similar level during the experiment (0.95 vs. 1.05), indicating a sealing of the intestinal barrier and beneficial changes in the cyclists' intestinal function. The supplementation resulted in a reduction in the concentrations of: tumor necrosis factor TNF-α after the aerobic (13.88 vs. 9.75) and anaerobic tests (8.54 vs. 6.8), IL-6 before (1.2 vs. 0.86) and after the anaerobic test (1.47 vs. 0.97), IL-10 before the anaerobic test (0.70 vs. 0.44), and the total oxidative status (TOS) of the blood plasma before (663.7 vs. 484.6) and after the anaerobic test (643.1 vs. 435.9). (4) Conclusions: The probiotic supplementation resulted in increased levels of the cyclists' aerobic capacity and their maintenance of anaerobic capacity and positively affected selected health indicators related to the exercise capacity of competitive road cyclists.


Assuntos
Consumo de Oxigênio , Probióticos , Adolescente , Adulto , Ciclismo/fisiologia , Teste de Esforço/métodos , Humanos , Interleucina-10 , Interleucina-6 , Oxigênio , Consumo de Oxigênio/fisiologia , Espécies Reativas de Oxigênio , Fator de Necrose Tumoral alfa , Adulto Jovem
20.
Artigo em Inglês | MEDLINE | ID: mdl-36231848

RESUMO

Mountain biking (MTB) is a cycling modality performed on a variety of unpaved terrain. Although the cross-country Olympic race is the most popular cross-country (XC) format, other XC events have gained increased attention. XC-MTB has repeatedly modified its rules and race format. Moreover, bikes have been modified throughout the years in order to improve riding performance. Therefore, the aim of this review was to present the most relevant studies and discuss the main results on the XC-MTB. Limited evidence on the topic suggests that the XC-MTB events present a variation in exercise intensity, demanding cardiovascular fitness and high power output. Nonetheless, these responses and demands seem to change according to each event. The characteristics of the cyclists differ according to the performance level, suggesting that these parameters may be important to achieve superior performance in XC-MTB. Moreover, factors such as pacing and ability to perform technical sections of the circuit might influence general performance. Bicycles equipped with front and rear suspension (i.e., full suspension) and 29″ wheels have been shown to be effective on the XC circuit. Lastly, strategies such as protective equipment, bike fit, resistance training and accident prevention measures can reduce the severity and the number of injuries.


Assuntos
Ciclismo , Esportes , Prevenção de Acidentes , Acidentes , Ciclismo/fisiologia , Exercício Físico
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