Relationship of critical speed derived from a 10-min submaximal treadmill test to 5-km and 10-km running performances.

It has been shown that the critical speed (CS) predicted from a perceptually self-regulated 10-min submaximal treadmill test (T10) is reliable and closely matches the CS estimated from conventional methods. To assess the relationship between the T10 and 5-km and 10-km running performances, 36 recreational runners (mean SD: age: 32.2 ± 6.2 years, height: 173.2 ± 7.3 cm, weight: 70.9 ± 8.8 kg, maximal oxygen uptake (V̇O2max): 53.3 ± 6.1 mL·kg-1·min-1) performed a ramp incremental test and 2 T10 tests (the first as a familiarization trial). Results showed that the T10 CS (3.9 ± 0.44 m·s-1) was significantly correlated with runners' last 6 months best performances in 5 km (20.3 ± 2.7 min; r = -0.90) and 10 km (42.7 ± 5.7 min; r = -0.91), the V̇O2max (r = 0.75), the speed associated with the gas exchange threshold (vGET: 3.38 ± 0.36 m·s-1; r = 0.76), the speed associated with the second ventilatory threshold (vVT2: 4.15 ± 0.49 m·s-1; r = 0.84), and the speed associated with the V̇O2max (vV̇O2max: 4.78 ± 0.54 m·s-1; r = 0.87). Moreover, 79% and 83% of the variance in 5-km and 10-km performances could be explained solely by the CS predicted from the T10. Results evidenced the strong relationship and practical performance relevance of the T10 CS test. Novelty: Critical speed derived from a 10-min submaximal treadmill test (T10) is significantly correlated with 5-km and 10-km running performances. The T10 critical speed test may represent a useful tool for assessing running performance capabilities.

Effect of Different Training Programs at Self-Selected Intensity on Body Composition, Perceptual Responses and Fitness Outcomes in Obese Women.

Obesity induces several disorders, such as android obesity, insulin resistance, and coronary/peripheral artery disease, and obese individuals commonly have low adherence to training programs. Exercise at self-selected intensity is a feasible strategy to avoid dropouts of training routines. We aimed to assess the effects of different training programs at self-selected intensity on body composition, ratings of perceived exertion (RPE), feelings of pleasure and displeasure (FPD) and fitness outcomes (maximum oxygen uptake (VO2max) and maximum dynamic strength (1RM)) in obese women. Forty obese women (n = 40; Body Mass Index: 33.2 ± 1.1 kg.m-2) were randomly allocated to combined training (CT = 10), aerobic training (AT = 10), resistance training (RT = 10) and control group (CG = 10). The frequency that CT, AT and RT performed the training sessions was 3 times per week during 8 weeks. Body composition (DXA), VO2max and 1RM were assessed at baseline and after intervention. All participants were on a restricted dietary intake aiming to ingest 2.650 kcal per day. Post hoc comparisons revealed that CT promotes a larger decrease in body fat percentage (p = 0.001), body fat mass (p = 0.004) than other groups. CT and AT elicited higher V•O2max increases (p = 0.014) than RT and CG, and 1RM values were higher in CT and RT (p = 0.001) than AT and CG at post-intervention. All training groups presented low RPE and high FPD over the training sessions, but only the CT was effective to reduce body fat percentage and body fat mass in obese women. In addition, CT was effective to increase simultaneously maximum oxygen uptake and maximum dynamic strength in obese women.

Frequency of physical activity and stress levels among Brazilian adults during social distancing due to the coronavirus (COVID-19): cross-sectional study

ABSTRACT BACKGROUND: The COVID-19 pandemic may be having many psychological impacts on people, at both an individual and a community level. OBJECTIVE: To ascertain the relationship between the weekly frequency of physical activity and levels of stress among Brazilian adults during social distancing due to the coronavirus (COVID-19), and the interaction of sex in this association. DESIGN AND SETTING: Cross-sectional study with a descriptive approach conducted at a public university in Curitiba (PR), Brazil. METHODS: 2,000 Brazilian adults (average age 36.4 years; 59.6% women) were recruited according to convenience through digital media. They filled out a questionnaire in electronic format that asked for sociodemographic information, health data, food consumption data, weekly frequency of physical activity and stress levels on the 10-item Kessler psychological distress scale. Descriptive statistics and regression analyses were used to evaluate the data. RESULTS: Associations were observed for the following correlations: male sex * no physical activity (odds ratio (OR): 4.35; 95% confidence interval (CI): 1.14-16.67); female sex * physical activity 4 or 5 times a week (OR: 7.86; 95% CI: 2.28-27.05); female sex * physical activity 3 times a week (OR: 7.32; 95% CI: 2.09-25.58); female sex * physical activity 1 or 2 times a week (OR: 14.57; 95% CI: 4.28-49.57); and female sex * no physical activity (OR: 24.17; 95% CI: 7.21-80.97). CONCLUSION: The lower the weekly frequency of physical activity during the period of social distancing was, the greater the chances of having stress levels were, especially for women.

Frequency of physical activity and stress levels among Brazilian adults during social distancing due to the coronavirus (COVID-19): cross-sectional study.

BACKGROUND: The COVID-19 pandemic may be having many psychological impacts on people, at both an individual and a community level. OBJECTIVE: To ascertain the relationship between the weekly frequency of physical activity and levels of stress among Brazilian adults during social distancing due to the coronavirus (COVID-19), and the interaction of sex in this association. DESIGN AND SETTING: Cross-sectional study with a descriptive approach conducted at a public university in Curitiba (PR), Brazil. METHODS: 2,000 Brazilian adults (average age 36.4 years; 59.6% women) were recruited according to convenience through digital media. They filled out a questionnaire in electronic format that asked for sociodemographic information, health data, food consumption data, weekly frequency of physical activity and stress levels on the 10-item Kessler psychological distress scale. Descriptive statistics and regression analyses were used to evaluate the data. RESULTS: Associations were observed for the following correlations: male sex * no physical activity (odds ratio (OR): 4.35; 95% confidence interval (CI): 1.14-16.67); female sex * physical activity 4 or 5 times a week (OR: 7.86; 95% CI: 2.28-27.05); female sex * physical activity 3 times a week (OR: 7.32; 95% CI: 2.09-25.58); female sex * physical activity 1 or 2 times a week (OR: 14.57; 95% CI: 4.28-49.57); and female sex * no physical activity (OR: 24.17; 95% CI: 7.21-80.97). CONCLUSION: The lower the weekly frequency of physical activity during the period of social distancing was, the greater the chances of having stress levels were, especially for women.

A submaximal treadmill test to predict critical speed.

We assessed the reliability and validity of a 10-min submaximal treadmill test (T10) to predict critical speed (CS). Forty-two runners completed a familiarization trial plus two experimental trials (T10 test and T10 retest). Reliability between the T10 test and T10 retest was assessed using coefficient of variation (CoV), limits of agreement (LoA) and intraclass correlation (ICC). For validity, the speed from the T10 retest was compared with the CS determined from 3 runs on separate days on a running track over 1200, 2400, and 3600 m (field test). Reliability between the T10 test and T10 retest showed a CoV of 3.4%, LoA of 0.05 ± 0.39 m.s-1, and an ICC of 0.93. Validity showed that speed (m.s-1) (T10 retest: 3.86 ± 0.51; field test: 3.88 ± 0.55) did not differ between trials. The T10 retest was highly correlated with the field test, r = 0.93, and the standard error for the estimate of CS using the T10 retest was 0.06 m.s-1, and the LoA was 0.02 ± 0.40 m.s-1. A submaximal 10-min treadmill test (T10) provides a practical and accessible method to estimate CS.

Effect of Music Tempo on Attentional Focus and Perceived Exertion during Self-selected Paced Walking.

This study investigated the influence of music on the rating of perceived exertion (RPE) and attentional focus during walking at a self-selected pace. Fifteen overweight and obese women volunteered to participate in the study. They underwent four sessions: the first for incremental maximal test and anthropometric measurement followed by three experimental sessions. After the first session, they were exposed to three 30-minute walking sessions at a self-selected pace in a counterbalanced order: fast-tempo music (FT), medium-tempo music (MT) and no-music control (NM). Borg's RPE Scale and an Attentional Focus Questionnaire were used to measure the perceptual response and attentional focus, respectively. Results showed that the RPE was higher in the no-music control than in the medium-tempo music (12.05 ± 0.6 vs. 10.5 ± 0.5). Furthermore, dissociative attentional focus was greater for both conditions with music in comparison with the no-music control (NM= 39.0 ± 4.1; MT= 48.4 ± 4.1 and FT= 47.9 ± 4.5). The results indicated that the use of music during walking can modulate attentional focus, increasing dissociative thought, and medium-tempo music can reduce the RPE.

Comparação da percepção subjetiva do esforço no limiar ventilatório entre os gêneros / Comparison the rating perceived exertion at ventilatory threshold between genders

O objetivo do estudo foi comparar a PSE no limiar ventilatório (LV) entre homens e mulheres. Participaram 17 homens (24,0 ± 3,3 anos) e 17 mulheres (22,5 ± 2,6 anos), submetidos a duas sessões experimentais com intervalo mínimo de 48 horas: (I) avaliação antropométrica e instruções referentes aos procedimentos e (II) teste máximo em esteira. Na análise estatística empregou-se teste t Student para verificar possíveis diferenças entre gêneros (p < 0,05). Não foram verificadas diferenças significativas entre homens e mulheres para a PSE LV (11,1 ± 1,8 e 12,1 ± 1,5, respectivamente). Apesar de as mulheres demonstrarem PSE superior em intensidade de exercício baseada em níveis absolutos, estas diferenças desaparecem quando homens e mulheres são testados em intensidade relativa de exercício. Conclui-se que homens e mulheres apresentam valores de PSE LV entre 12 e 13 ("leve" e "algo difícil") durante teste de esforço máximo.

The purpose of the present study was to compare the rating of perceived exertion (RPE) at ventilatory threshold (VT) during graded treadmill exercise between men and women. Participated 17 men (24.0 ± 3.3 years) and 17 women (22.5 ± 2.6 years) were submitted to two experimental sessions with a minimum interval of 48 hours: (I) anthropometric evaluation and instructions regarding the procedures, and (II) graded treadmill exercise. For statistical analysis, was employed used t Student test to verify possible differences between genders (p > 0.05). There were no significant differences between genders to RPE VT (11.7 ± 1.8 and 12.2 ± 1.5, respectively). Although women had a higher RPE to exercise intensity based on absolute levels, these differences were minimized or disappeared when men and women were compared at similar relative exercise intensity. The result of present study showed that men and women had a similar RPE VT between 12 and 13 ("light" and "something hard") during graded treadmill exercise.

Fatores associados ao excesso de peso corporal em escolares da tríplice fronteira: Argentina, Brasil e Paraguai / Factors associated with overweight in students from tri-border region: Argentina, Brazil and Paraguay

A região da Tríplice Fronteira apresenta diversos problemas sociais e de saúde na população jovem, contudo, não há informações sobre a proporção de adolescentes com excesso de peso corporal. Este estudo investigou a prevalência de excesso de peso corporal e os fatores associados em escolares da Tríplice Fronteira: Argentina, Brasil e Paraguai. Participaram do estudo 1.183 escolares, de 15 a 18 anos de idade. O excesso de peso corporal foi identificado segundo os pontos de corte do índice de massa corporal, propostos pela Organização Mundial de Saúde. O questionário do Global School-Based Student Health Survey foi utilizado para identificar fatores sociodemográficos (sexo e faixa etária) e comportamentais (atividade física fora da escola, deslocamento à escola, tempo assistindo TV e consumo de frutas, vegetais, doces e salgados) associados ao excesso de peso corporal. Utilizou-se a estatística descritiva, análise de variância, qui-quadrado e regressão logística binária, adotando-se p< 1 vez/dia) tiveram 2,2 e 2,9 vezes mais chances de ter excesso de peso corporal do que seus pares que realizavam deslocamento ativo e que consumiam vegetais diariamente, respectivamente. Estes resultados sugerem que políticas públicas de combate ao excesso de peso corporal devem focar a promoção hábitos saudáveis entre os jovens da Tríplice Fronteira.

The Tri-Border Region has several social and health problems among young people, however, there are no data about the overweight between adolescents. This study investigated the prevalence of overweight and associated factors in students from Tri-Border Region: Argentina, Brazil and Paraguay. Study participants were 1.183 students, ages from 15 to 18 years. The overweight was identified according to body mass index cut-off points proposed by the World Health Organization. The Global School-Based Student Health Survey questionnaire was used to identify sociodemographic (gender and age) and behavioral factors (physical activity outside of school, commuting to school, time watching TV and fruits, vegetables, sweet, and salty snack consumption) associated with overweight in adolescents. It was used the descriptive statistics, analysis of variance, chi-square and binary logistic regression, adopting p< 1 time/day) were 2,2 and 2,9 times more likely to have overweight than their counterparts who performed active commuting to school and consumed vegetables daily, respectively. These results suggest that public policies to combat overweight should attention on promoting healthy lifestyle among young people from Tri-Border Region.

[Factors associated with overweight in students from tri-border region: Argentina, Brazil and Paraguay]. / Fatores associados ao excesso de peso corporal em escolares da tríplice fronteira: Argentina, Brasil e Paraguai.

The Tri-Border Region has several social and health problems among young people, however, there are no data about the overweight between adolescents. This study investigated the prevalence of overweight and associated factors in students from Tri-Border Region: Argentina, Brazil and Paraguay. Study participants were 1.183 students, ages from 15 to 18 years. The overweight was identified according to body mass index cut-off points proposed by the World Health Organization. The Global School-Based Student Health Survey questionnaire was used to identify sociodemographic (gender and age) and behavioral factors (physical activity outside of school, commuting to school, time watching TV and fruits, vegetables, sweet, and salty snack consumption) associated with overweight in adolescents. It was used the descriptive statistics, analysis of variance, chi-square and binary logistic regression, adopting p < 0.05. Thirteen percent of students were overweight. Boys were approximately two times more likely to have overweight than girls, independently of nationality. Brazilian students that realized passive commuting to school and Argentineans students with low consumption of vegetables (< 1 time/day) were 2.2 and 2.9 times more likely to have overweight than their counterparts who performed active commuting to school and consumed vegetables daily, respectively. These results suggest that public policies to combat overweight should attention on promoting healthy lifestyle among young people from Tri-Border Region.

Energy cost and energy sources of a ballet dance exercise in female adolescents with different technical ability.

This study evaluated energy cost and energy sources of a ballet exercise (grand adage) in young female dancers with different technical ability, and then related the energy sources to the subject's VO(2max) and anaerobic threshold (IAT). Twenty-five dancers (13-16 years) were divided into two different technical ability groups: low-level (n = 13) and high-level (n = 12). The overall energy requirement of dance exercise (VO(2eq)) was obtained by adding the amount of VO(2) during exercise above resting (aerobic source or VO(2ex)) to the VO(2) up to the fast component of recovery (anaerobic alactic source or VO(2al)) and to the energy equivalent of peak blood lactate accumulation (anaerobic lactic source or VO(2la) of recovery. VO(2eq) of exercise amounted to 81 +/- 10 and 94 +/- 9 ml kg(-1) in low-level and high-level groups, respectively. VO(2ex) represented the higher fraction (65 +/- 4% and 77 +/- 5%) in low-level and high-level groups, respectively, of VO(2eq )in both the groups. In the low-level group the remaining fractions were: 23 +/- 2 % for VO(2al) and 12 +/- 1% for VO(2la). In high-level group the remaining fractions were: 18 +/- 2 % for VO(2al) and 4 +/- 1% for VO(2la). Between two groups, significant differences were found in VO(2ex )(P < 0.01), VO(2al) (P < 0.01), and VO(2al )(P < 0.05). IAT was 55 and 60% of VO(2max) for low-level and high-level dancers, respectively. Low-level dancers performed more exercise above IAT than high-level. For these reasons, it should be better to define exercise intensity according to the IAT parameter and not only to VO(2max).

Imagery intervention in open and closed tennis motor skill performance.

To assess use of imagery intervention in performance of two tennis motor skills the quasi-experimental design included a pre- and posttest and a control group. The tennis service shot and service receiving skill were selected as representative of open and closed skills, respectively. 48 subjects, male tennis players, whose ages ranged from 16 to 18 yr. (M = 17.2), were divided into two groups: (1) Technical practice only which was used as control group and (2) Imagery group who received both imagery and technical practice. Analysis of covariance showed a significant main effect for the imagery intervention on the closed skill (p = .002). Findings suggest that imaging a positive outcome may be more powerful in improving performance of closed skill movements than of open skill movements.