116 research outputs found
The influence of heavy goods vehicle traffic on accidents on different types of Spanish interurban roads
This paper illustrates a methodology developed to analyze the influence of traffic conditions, i.e. volume and composition on accidents on different types of interurban roads in Spain, by applying negative binomial models. The annual average daily traffic was identified as the most important variable, followed by the percentage of heavy goods vehicles, and different covariate patterns were found for each road type. The analysis of hypothetical scenarios of the reduction of heavy goods vehicles in two of the most representative freight transportation corridors, combined with hypotheses of total daily traffic mean intensity variation, produced by the existence or absence of induced traffic gives rise to several scenarios. In all cases a reduction in the total number of accidents would occur as a result of the drop in the number of heavy goods transport vehicles, However the higher traffic intensity, resulting of the induction of other vehicular traffic, reduces the effects on the number of accidents on single carriageway road segments compared with high capacity roads, due to the increase in exposure. This type of analysis provides objective elements for evaluating policies that encourage modal shifts and road safety enhancements
Cardiorespiratory optimal point as a submaximal evaluation tool in endurance athletes: an exploratory study
Introduction: The cardiorespiratory optimal point (COP) represents the lowest minute
ventilation to oxygen consumption ratio (VE/VO2) and can be estimated during a CPET at
submaximal intensity when an exercise test until volitional fatigue is not always advisable
(i.e., a conflict zone where you cannot be confident of the security because nearcompetition, off-season, among other). COPâs physiological components have not been
wholly described yet. Therefore, this study seeks to identify the determinants of COP in
highly trained athletes and its influence on maximum and sub-maximum variables during
CPET through principal c omponent analysis (PCA) (explains the datasetâs variance).
Methods: Female (n = 9; age, 17.4 ± 3.1 y; maximal VO2 [VO2max]), 46.2 ± 5.9 mL/
kg/min) and male (n = 24; age, 19.7 ± 4.0 y; VO2max, 56.1 ± 7.6 mL/kg/min) athletes
performed a CPET to determine the COP, ventilatory threshold 1 (VT1) and 2 (VT2),
and VO2max. The PCA was used to determine the relationship between variables and
COP, explaining their variance.
Results: Our data revealed that females and males displayed different COP values.
Indeed, males showed a significant diminished COP compared to the female group
(22.6 ± 2.9 vs. 27.2 ±3.4 VE/VO2, respectively); nevertheless, COP was allocated
before VT1 in both groups.
Discussion: PC analysis revealed that the COP variance was mainly explained (75.6%) by
PC1 (expired CO2 at VO2max) and PC2 (VE at VT2), possibly influencing cardiorespiratory
efficiency at VO2max and VT2. Our data suggest that COP could be used as a
submaximal index to monitor and assess cardiorespiratory system efficiency in
endurance athletes. The COP could be particularly useful during the offseason and
competitive periods and the return to the sports continuum.This study was supported by Minera Escondida Ltda. MEL2203; the âAgencia Nacional de InvestigaciĂłn y Desarrollo (ANID)â, through Fondecyt de IniciaciĂłn #11220870 and Anillo ACT210083
The effects of interset rest on adaptation to 7 weeks of explosive training in young soccer players
The aim of the study was to compare the effects of plyometric
training using 30, 60, or 120 s of rest between sets on explosive
adaptations in young soccer players. Four groups of athletes
(age 10.4 ± 2.3 y; soccer experience 3.3 ± 1.5 y) were randomly
formed: control (CG; n = 15), plyometric training with 30 s
(G30; n = 13), 60 s (G60; n = 14), and 120 s (G120; n = 12) of
rest between training sets. Before and after intervention players
were measured in jump ability, 20-m sprint time, change of
direction speed (CODS), and kicking performance. The training
program was applied during 7 weeks, 2 sessions per week, for a
total of 840 jumps. After intervention the G30, G60 and G120
groups showed a significant (p = 0.0001 â 0.04) and small to
moderate effect size (ES) improvement in the countermovement
jump (ES = 0.49; 0.58; 0.55), 20 cm drop jump reactive strength
index (ES = 0.81; 0.89; 0.86), CODS (ES = -1.03; -0.87; -1.04),
and kicking performance (ES = 0.39; 0.49; 0.43), with no
differences between treatments. The study shows that 30, 60,
and 120 s of rest between sets ensure similar significant and
small to moderate ES improvement in jump, CODS, and kicking
performance during high-intensity short-term explosive training
in young male soccer players
Exercise during pregnancy on maternal lipids: a secondary analysis of randomized controlled trial
Background: Today, scientific evidence has supported the popular belief that physical activity is associated
with biological health in pregnant women. A randomized controlled trial was used to assess the benefits of
physical exercise during pregnancy on maternal lipids in low-income Latina women.
Methods: The study included 67 nulliparous low-income Latina women in gestational weeks 16â20, randomly
assigned into one of two groups: 1) The exercise group, which took part in aerobic and resistance exercise
for 60min, three times a week for 12 weeks, 2) The control group, which undertook their usual physical activity and prenatal
care. The primary outcomes were changes in maternal blood lipids after intervention. Obstetrical and neonatal outcomes
measured were type of delivery, postpartum hemorrhage, newborn and/or maternal complicationsâ, gestational age,
weight gain, birth weight, foetal growth, and Apgar score.
Results: Fifty women completed the study. At the end of the intervention, there were differences between
groups in low-density lipoprotein levels (mean change: â8 mg/dL, 95%CI -3 to â29; P < 0.001) and triglycerides
(mean change: â6 mg/dL, 95%CI -1 to â11; P = 0.03). Also, compared with women who remained in the
control group, active women showed lower complications during delivery (moderate postpartum haemorrhage)
(58% compared with 75%; P < 0.05) and lower complications in newborns (e.g. cyanosis or respiratory distress)
(21% compared with 46%; P < 0.001).
Conclusions: An exercise programme during the second and third trimester favours less gain in low-density lipoprotein
cholesterol and triglycerides fewer delivery and neonatal complications.The authors would like to acknowledge Universidad del Valle for the
financial support to the Nutrition Group (Grant N. CI 1575) and Instituto
Colombiano para el Desarrollo de la Ciencia y la TecnologĂa âFrancisco
JosĂ© de Caldasâ (Grant N. 656,640,820,391). Robinson RamĂrez-Velez
received a grant from Instituto Colombiano para el Desarrollo de la
Ciencia y la TecnologĂa âFrancisco JosĂ© de Caldasâ to do a doctorate
and received a grant from American College Sport Medicine to the
Fellow in CDC Atlanta (RAFA-PANA Scholarship)
Schoolbag weight carriage in Portuguese children and adolescents: a cross-sectional study comparing possible influencing factors
Background Schoolbags and the consequences of carrying them, particularly those associated with overload, are often studied as a health concern. Modifications in gait and posture were reported when children carried loads that corresponded to more than 10% of their body weight (BW). The aims of this study were to verify the load that is carried by Portuguese students and how it is influenced by factors such as school grade, school schedule, lunch site, physical education, sex and body mass index (BMI). Acquiring a more specific knowledge of the Portuguese context and understanding the influence of these factors may allow us to generate proposals to control them in ways that benefit students.MethodsThe load carried by students in the 5th grade (10.60.4years) and 9th grade (14.70.6years) were weighed with a luggage scale on all days of the week, resulting in 680 evaluations. Data related to the school day were also collected, such as the student's lunch site, how he or she got to school and his or her school schedule for that day. Individual height and weight were also assessed. Results The 5th grade students carried greater loads than the 9th grade students, resulting in a substantial difference relative to their BW. The school loads of the 5th grade students were mostly greater than 10% of their BWs. Girls tended to carry heavier loads than boys, and overweight students also tended to carry heavier loads. Students who could eat lunch at home carried less weight, and on physical education days, the total load carried increased, but the backpacks of the 5th grade students were lighter.Conclusions The results of the current study describe excessive schoolbag weight among Portuguese students and expound on some of the factors that influence it, which can help researchers and professionals design a solution to decrease children's schoolbag loads.Funds through FCT - Portuguese Foundation for Science and Technology (UID/DTP/04045/2019) - and the European Fund for regional development (FEDER) allocated by European Union through the COMPETE 2020 Programme (POCI-01-0145-FEDER-006969), and through the Project NanoSTIMA: Macro-to-Nano Human Sensing, Towards Integrated Multimodal Health Monitoring and Analytics (NORTE-01-0145-FEDER-000016), co-financed by Fundo Europeu de Desenvolvimento Regional (FEDER) -NORTE 2020
Eleven-month longitudinal study of antibodies in SARS-CoV-2 exposed and naĂŻve primary health care workers upon COVID-19 vaccination
We evaluated the kinetics of antibody responses to Two years into the COVID-19 pandemic and 1 year after the start of vaccination rollout, the world faced a peak of cases associated with the highly contagious Omicron variant of concern (VoC) of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike (S) and nucleocapsid (N) antigens over five cross-sectional visits (January-November 2021), and the determinants of pre-booster immunoglobulin levels, in a prospective cohort of vaccinated primary health care workers in Catalonia, Spain. Antibodies against S antigens after a full primary vaccination course, mostly with BNT162b2, decreased steadily over time and were higher in pre-exposed (n = 247) than naive (n = 200) individuals, but seropositivity was maintained at 100% (100% IgG, 95.5% IgA, 30.6% IgM) up to 319 days after the first dose. Antibody binding to variants of concern was highly maintained for IgG compared to wild type but significantly reduced for IgA and IgM, particularly for Beta and Gamma. Factors significantly associated with longer-term antibodies included age, sex, occupation, smoking, adverse reaction to vaccination, levels of pre-vaccination SARS-CoV-2 antibodies, interval between disease onset and vaccination, hospitalization, oxygen supply, post COVID and symptomatology. Earlier morning vaccination hours were associated with higher IgG responses in pre-exposed participants. Symptomatic breakthroughs occurred in 9/447 (2.01%) individuals, all among naive (9/200, 4.5%) and generally boosted antibody responses. Additionally, an increase in IgA and/or IgM seropositivity to variants, and N seroconversion at later time points (6.54%), indicated asymptomatic breakthrough infections, even among pre-exposed. Seropositivity remained highly stable over almost a year after vaccination. However, gradually waning of anti-S IgGs that correlate with neutralizing activity, coupled to evidence of an increase in breakthrough infections during the Delta and Omicron predominance, provides a rationale for booster immunization
Effects of an exercise program on hepatic metabolism, hepatic fat, and cardiovascular health in overweight/obese adolescents from BogotĂĄ, Colombia (the HEPAFIT study): study protocol for a randomized controlled trial
Background: A considerable proportion of contemporary youth have a high risk of obesity-related disorders such
as cardiovascular disease, metabolic syndrome, or non-alcoholic fatty liver disease (NAFLD). Although there is consistent
evidence for the positive effects of physical activity on several health aspects, most adolescents in Colombia are
sedentary. It is, therefore, important to implement strategies that generate changes in lifestyle. The HEPAFIT study
aims to examine whether a 6-month exercise program has benefits for hepatic fat content and cardiovascular health
outcomes among overweight/obese adolescents from BogotĂĄ, Colombia.
Methods/design: Altogether, 100 hundred overweight/obese, sedentary adolescents (aged 11â17 years) attending two
public schools in BogotĂĄ, Colombia, will be included in a parallel-group randomized controlled trial. Adolescents will be
randomly assigned to an intervention group following one of four curricula: (1) the standard physical education
curriculum (60 min per week of physical activity, n = 25) at low-to-moderate intensity; (2) a high-intensity physical
education curriculum (HIPE, n = 25), consisting of endurance and resistance games and non-competitive activities,
such as running, gymkhanas, lifting, pushing, wrestling, or hauling, for 60-min sessions, three times per week, with
an energy expenditure goal of 300 to 500 kcal/session at 75â85% maximum heart rate (HRmax); (3) a low-to-moderate
intensity physical education curriculum (LIPE, n = 25) consisting of endurance and resistance games and non-competitive
activities (e.g., chasing, sprinting, dribbling, or hopping) for 60-min sessions, three times per week with an energy
expenditure goal of 300 kcal/session at 55â75% HRmax; and (4) a combined HIPE and LIPE curriculum (n = 25).
The HIPE, LIPE, and combined interventions were performed in addition to the standard physical education curriculum.
The primary outcome for effectiveness is liver fat content, as measured by the controlled attenuation parameter 1
week after the end of the intervention program.
Discussion: The translational focus may be suitable for collecting new information in a school setting on the
possible effects of physical activity interventions to reduce liver fat content and to improve metabolic profiles
and the cardiometabolic health of overweight/obese adolescents. This may lead to the more efficient use of
school physical education resources.The HEPAFIT study was carried out with the financial support of Instituto
Colombiano para el Desarrollo de la Ciencia y la TecnologĂa âFrancisco JosĂ©
de Caldasâ COLCIENCIAS (code 59700 and no 122277757900). Katherine
GonzĂĄlez-RuĂz receive a scholarship from Universidad del Rosario, Colombia,
Escuela de Medicina y Ciencias de la Salud, to do a Doctorate. This article
presents independent research commissioned by COLCIENCIAS under its
Program Grants for Applied Research funding scheme (Convocatoria 777â2017)
The insulin-like growth factor system is modulated by exercise in breast cancer survivors: a systematic review and meta-analysis
Abbreviations: CI, Confidence interval; ELISA, Enzyme-linked immunosorbent assay; IGF, Insulin-like growth factors;
IGFBP, Insulin-like growth factor binding protein; MD, Mean difference; PEDro, Physiotherapy evidence database;
RCT, Randomized controlled trials; SD, Standard deviation.Background: Insulin-like growth factors (IGFÂŽs) play a crucial role in controlling cancer cell proliferation,
differentiation and apoptosis. Exercise has been postulated as an effective intervention in improving cancerrelated
outcomes and survival, although its effects on IGFÂŽs are not well understood. This meta-analysis aimed
to determine the effects of exercise in modulating IGFÂŽs system in breast cancer survivors.
Methods: Databases of PuMed, EMBASE, Cochrane Central Register of Controlled Trials, EMBASE, ClinicalTrials.
gov, SPORTDiscus, LILACS and Scopus were systematically searched up to November 2014. Effect estimates were
calculated through a random-effects model of meta-analysis according to the DerSimonian and Laird method.
Heterogeneity was evaluated with the I2 test. Risk of bias and methodological quality were evaluated using the
PEDro score.
Results: Five randomized controlled trials (n = 235) were included. Most women were post-menopausal. Highquality
and low risk of bias were found (mean PEDro score = 6.2 ± 1). Exercise resulted in significant improvements
on IGF-I, IGF-II, IGFBP-I, IGFBP-3, Insulin and Insulin resistance (P < 0.05). Non-significant differences were found for
Glucose. Aerobic exercise improved IGF-I, IGFBP-3 and Insulin. No evidence of publication bias was detected by
EggerÂŽs test (p = 0.12).
Conclusions: Exercise improved IGFÂŽs in breast cancer survivors. These findings provide novel insight regarding the
molecular effects of exercise on tumoral microenvironment, apoptosis and survival in breast cancer survivors
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