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1.
J Aging Phys Act ; : 1-10, 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-39019446

RESUMO

BACKGROUND: Cadence-controlled walking may be a desirable approach for older adults to self-monitor exercise intensity and achieve physical activity guidelines. We examined the acute effects of cadence-controlled walking on cognition and vascular function in physically inactive older adults. METHODS: In a randomized crossover design, 26 participants (65% females, 67.8 ± 11.3 years) underwent 30-min acute exercise (walking at 100 steps/min) and control (sitting) conditions. We measured cognition, central blood pressure (BP), and arterial stiffness before, and immediately, after each condition. RESULTS: We observed significant Time × Condition interactions in the Flanker Inhibitory Control and Attention (Flanker) test and Dimensional Change Card Sort (DCCS) test scores, and in central systolic BP, central pulse pressure, and carotid to femoral pulse wave velocity (p < .05). The Flanker and DCCS scores significantly increased after walking (d = 0.4 and 0.5, respectively), but not after sitting. Central systolic BP, central pulse pressure, and carotid to femoral pulse wave velocity significantly increased after sitting but remained unchanged after acute walking (d = 0.4-0.2), with p-values < .05. After walking, significant correlations were observed between DCCS and diastolic BP and central pulse pressure change scores and change scores in central pulse wave velocity, Flanker, and DCCS (rs = -0.45 to -0.52). CONCLUSION: These findings suggest that a single bout of cadence-controlled walking elicited an immediate improvement in cognition and might have mitigated increases in arterial stiffness and central BP observed in the seated control condition. Further research is needed to examine the association between cognition and vascular function following acute exercise compared to control conditions. SIGNIFICANCE: Our findings may have practical implications for developing daily physical activity recommendations for improving the cognitive health for successful aging.

2.
Fam Community Health ; 40(1): 3-10, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-27870747

RESUMO

The overall objective of Project SHAPE (Shaping Health using Activity Photovoice and E-Video) was to improve physical activity levels of rural, medically underserved children by designing and implementing a culturally relevant physical activity intervention. This objective was met by using a community-based participatory research approach to design and implement an intervention that would positively affect the psychosocial constructs related to increasing physical activity, which, in turn, would lead to increases in the time spent in daily physical activity. This article describes the unique design of the intervention including its theoretical framework, its interrelated components, and the logistics involved.


Assuntos
Pesquisa Participativa Baseada na Comunidade/métodos , Exercício Físico/fisiologia , Criança , Feminino , Humanos , Masculino , Projetos de Pesquisa , População Rural
3.
J Strength Cond Res ; 31(7): 1963-1972, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27669193

RESUMO

Nickerson, BS, Esco, MR, Bishop, PA, Schumacker, RE, Richardson, MT, Fedewa, MV, Wingo, JE, and Welborn, BA. Validity of selected bioimpedance equations for estimating body composition in men and women: a four-compartment model comparison. J Strength Cond Res 31(7): 1963-1972, 2017-The purpose of this study was to compare body fat percentage (BF%) and fat-free mass (FFM) values from bioelectrical impedance analysis (BIA) equations to values determined from a 4-compartment (4C) model. Eighty-two adults (42 men and 40 women) volunteered to participate (age = 23 ± 5 years). Body fat percentage and FFM were estimated from previously developed BIA equations by Chumlea et al. (BIACH), Deurenberg et al. (BIADE), Kyle et al. (BIAKYLE), and Sun et al. (BIASUN). Four-compartment model body composition was derived from underwater weighing for body density, dual-energy X-ray absorptiometry for bone mineral content, and bioimpedance spectroscopy for total body water. The standard error of estimate (SEE) for group BF% and FFM ranged from 3.0 to 3.8% and 2.1 to 2.7 kg, respectively. The constant error (CE) was significantly higher and lower for BF% and FFM (p < 0.001), respectively, for 3 BIA equations (BIACH, CE = 3.1% and -2.2 kg; BIADE, CE = 3.7% and -2.9 kg; BIAKYLE, CE = 2.3% and -1.9 kg), but was not significant for BF% (p = 0.702) and FFM (p = 0.677) for BIASUN (CE = -0.1% and 0.1 kg). The 95% limits of agreement were narrowest for BIACH (±5.9%; ±4.2 kg) and largest for BIADE (±7.4%; ±6.2 kg). The significant CE yielded by BIACH, BIADE, and BIAKYLE indicates these equations tend to overpredict group BF% and underestimate group FFM. However, all BIA equations produced low SEEs and fairly narrow limits of agreement. When the use of a 4C model is not available, practitioners might consider using one of the selected BIA equations, but should consider the associated CE.


Assuntos
Tecido Adiposo/fisiologia , Composição Corporal , Impedância Elétrica , Absorciometria de Fóton , Adulto , Feminino , Humanos , Masculino , Reprodutibilidade dos Testes , Adulto Jovem
4.
J Strength Cond Res ; 31(9): 2519-2527, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27806008

RESUMO

Nickerson, BS, Esco, MR, Bishop, PA, Schumacker, RE, Richardson, MT, Fedewa, MV, Wingo, JE, and Welborn, BA. Impact of measured vs. predicted residual lung volume on body fat percentage using underwater weighing and 4-compartment model. J Strength Cond Res 31(9): 2519-2527, 2017-The purpose of this study was to compare underwater weighing (UWW) and 4-compartment (4C) model body fat percentage (BF%) for predicted vs. simultaneously measured residual lung volume (RLV). Forty-seven women and 33 men (age = 22 ± 5 years) had UWW and 4C model BF% determined using Boren et al. (RLVBOREN), Goldman and Becklake (RLVGB), and Miller et al. (RLVMILLER) RLV prediction equations. Criterion UWW BF% included body density (BD) values with simultaneous RLV. Criterion 4C model BF% included BD through UWW with simultaneous RLV, total body water through bioimpedance spectroscopy, and bone mineral content through dual-energy x-ray absorptiometry. The standard error of estimate (SEE) for UWW and 4C model BF% determined through RLV prediction equations varied from 2.0 to 2.6% and from 1.3 to 1.5%, respectively. The constant error (CE) was significantly different for UWW BF% when using RLVBOREN, RLVGB, and RLVMILLER (all p < 0.016; CE = 0.7, -2.0, 1.0%, respectively). However, the CEs for RLVBOREN and RLVMILLER were not significant in the 4C model (p = 0.73 and 0.11; CE = 0.1 and 0.2%, respectively), whereas RLVGB remained significantly different (p < 0.001; CE = -1.5%). The 95% limits of agreement were less than ±5.2% for UWW BF% and less than ±3.1% for the 4C model when using the 3 RLV equations. When used in a 4C model, the RLV equations yielded a smaller CE, SEE, and 95% limits of agreement than UWW BF% results. However, because of the range of individual error shown in the current study, caution should be employed when using the 4C model as a criterion method with predicted RLV.


Assuntos
Tecido Adiposo/fisiologia , Pulmão/fisiologia , Água , Absorciometria de Fóton , Adolescente , Adulto , Composição Corporal , Água Corporal , Peso Corporal , Densidade Óssea , Feminino , Humanos , Medidas de Volume Pulmonar , Masculino , Reprodutibilidade dos Testes , Adulto Jovem
5.
J Biophotonics ; 17(4): e202300518, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38282462

RESUMO

PURPOSE: This study examined the agreement between %Fat measurements using a smartphone-based application (IMAGE) across different environmental conditions. METHODS: A single reference image was obtained using an 8 MP smartphone camera under Ambient Light in front of a white background. Additional photos were obtained using a 0.7 MP, 5 MP, and 12 MP smartphone cameras; low-, moderate-, and bright-lighting conditions; and various color backgrounds including black, green, orange, and gray. RESULTS: %Fat measured using the 0.7 MP camera (27.8 ± 6.2 %Fat) was higher than the reference (26.8 ± 6.1 %Fat) (p < 0.001). The black (32.0 ± 12.0 %Fat), green (27.5 ± 6.3 %Fat), and gray (27.8 ± 6.3 %Fat) backgrounds yielded higher %Fat than the white (p = 0.03, 0.01, and 0.001). All camera, lighting, and background conditions were strongly correlated with the reference (all intraclass correlation coefficient [ICC] >0.98, all standard error of the estimate [SEE] <1.5 %Fat, all p < 0.001), except the black background which yielded poorer agreement with the white background (ICC = 0.69, SEE = 4.5%, p < 0.001). CONCLUSION: %Fat from IMAGE were strongly correlated across various environmental conditions.


Assuntos
Processamento de Imagem Assistida por Computador , Smartphone , Processamento de Imagem Assistida por Computador/métodos , Iluminação , Composição Corporal
6.
Eur J Appl Physiol ; 112(2): 725-34, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21656227

RESUMO

This study examined heat stress, heart rate (HR), fluid balance, micro-environment temperature and humidity with Islamic athletic clothing (IC) compared to traditional soccer uniform (SC). Ratings of perceived exertion (RPE), session RPE (S-RPE), comfort, and cooling response were also examined. Female volunteers (N = 8) completed a treadmill [Formula: see text] test and then, in a randomized, counter-balanced order, two intermittent running bouts (45 min total) in a hot environment (30.0°C WBGT) in IC and SC. Thereafter, participants sat for 40 min in the hot ambient environment. Repeated measures ANOVA revealed significantly greater micro-environment temperature (p = 0.02) (IC 33.3 ± 3.2°C, SC 32.0 ± 2.8°C) and humidity (p = 0.04) (IC 48.4 ± 8.1%, SC 42.9 ± 7.9%) in IC during the exercise trial but no difference in the 40-min recovery period for micro-environment temperature (p = 0.25) or humidity (p = 0.18). No significant difference (p > 0.05) was shown for core temperature (T (rec)) (IC 38.3 ± 0.4°C, SC 38.2 ± 0.4°C), HR (IC l54 ± 28 beats min(-1), SC 151 ± 26 beats min(-1)) or RPE (IC 4.7 ± 2.1, SC 3.8 ± 1.7) during the exercise trial or recovery period. Results from a paired t test revealed a significantly greater (p < 0.05) S-RPE (IC 5.8 ± 1.2, SC 4.3 ± 1.9), sweat loss (IC 1.4 ± 0.4 L h(-1), SC 1.2 ± 0.4 L h(-1)) and greater discomfort during the exercise and recovery period for the IC. IC clothing appears to have no detrimental effects on heat storage or heat strain during exercise or recovery.


Assuntos
Regulação da Temperatura Corporal/fisiologia , Vestuário , Exercício Físico/fisiologia , Resposta ao Choque Térmico/fisiologia , Islamismo , Equipamentos Esportivos , Equilíbrio Hidroeletrolítico/fisiologia , Feminino , Humanos , Adulto Jovem
7.
J Strength Cond Res ; 26(12): 3297-303, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22237141

RESUMO

The purpose of this study was to evaluate the effects of 3 types of warm-up (WU) on swimming performance, reaction time, and dive distance. In repeated-measures counterbalanced design, National Collegiate Athletic Association Division I swimmers (n = 16) used 3 WUs before performing 50-yd (45.7-m) freestyle swim trials. The WU consisted of (a) no WU, (b) short WU (50-yd at 40% of swimmers' maximal effort and 50-yd at 90%), and (c) regular WU (usual precompetition WU). The mean 50-yd time was significantly faster (p = 0.01) after the regular WU (24.95 ± 1.53 seconds) when compared with that of the short WU (25.26 ± 1.61 seconds). However, individual data indicated that 19% of the participants performed their best in the 50-yd category after short, 37% after no, and 44% after regular WU. Heart rate was significantly higher (p = 0.01) after regular WU (100 ± 13 b·min(-1)) when compared with that of the no WU category (88 ± 18 b·min(-1)). However, no significant differences among WUs were found for reaction time (p = 0.96), rating of perceived exertion post 50-yd time trial (p = 0.11), dive distance (p = 0.67), or stroke count (p = 0.23). In conclusion, the average regular WU was better than short or noWU to achieve the fastest mean time in the 50-yd freestyle; however, some individual performances were faster after WUs different from their regular approach.


Assuntos
Desempenho Atlético/fisiologia , Mergulho/fisiologia , Tempo de Reação , Natação/fisiologia , Adaptação Fisiológica , Análise de Variância , Tolerância ao Exercício , Feminino , Frequência Cardíaca/fisiologia , Humanos , Masculino , Exercícios de Alongamento Muscular , Inquéritos e Questionários , Adulto Jovem
8.
J Strength Cond Res ; 26(5): 1348-52, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22516908

RESUMO

The purpose of this study was to examine 2 recovery modalities (with and without an ice bag treatment) on closed-handed and open-handed weight-assisted pull-ups in recreationally-trained rock climbers. Healthy and recreationally active volunteers (n = 9) completed 4 counterbalanced trials separated by 72 hours. Trials included 3 sets of closed-handed and open-handed weight-assisted pull-ups supported by 50% of body weight, until failure. Between each set, participants sat quietly in a chair and engaged in approximately 20 minutes of either passive or ice bag treatment. Ice bags were placed on the participants' arms and shoulders. Heart rate (HR), ratings of perceived exertion (RPE), session-RPE (S-RPE), and perceived recovery were also assessed. Hand-grip strength pretrial and posttrial was not different between ice bag conditions. Also, there were no differences between treatments for HR, RPE, perceived recovery, S-RPE, or comfort ratings. The overall number of open-handed pull-ups (mean ± SD = 19 ± 5) was lower than closed-handed pull-ups (34 ± 14; p < 0.001). Ice bag recovery attenuated the decrease in open-handed pull-up performance for sets 2 (22 ± 5; p = 0.004) and 3 (22 ± 5; p = 0.003) relative to set 3 using passive recovery only (i.e., no ice bag; 17 ± 6). There were no differences (p = 0.31) between treatments for closed-handed pull-ups. The findings support the recommendations to use ice bags for recovery between bouts of rock climbing that involve a predominantly open-handed grip to maintain performance.


Assuntos
Crioterapia , Força da Mão/fisiologia , Montanhismo/fisiologia , Recuperação de Função Fisiológica , Treinamento Resistido , Descanso/fisiologia , Adulto , Análise de Variância , Terapia Combinada , Frequência Cardíaca , Humanos , Masculino , Esforço Físico , Adulto Jovem
9.
J Strength Cond Res ; 25(3): 620-8, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20581704

RESUMO

The aim of this study was to develop and test the practical utility of a perceived recovery status (PRS) scale. Sixteen volunteers (8 men, 8 women) performed 4 bouts of high-intensity intermittent sprint exercise. After completion of the baseline trial, in a repeated-measures design, subjects were given variable counterbalanced recovery periods of 24, 48, and 72 hours whereupon they repeated an identical intermittent exercise protocol. After a warm-up period, but before beginning each subsequent bout of intermittent sprinting, each individual provided their perceived level of recovery with a newly developed PRS scale. Similar to perceived exertion during exercise, PRS was based on subjective feelings. The utility of the PRS scale was assessed by measuring the level of agreement of an individual's perceived recovery relative to their performance during the exercise bout. Perceived recovery status and change (both positive and negative) in sprint performance during multiple bouts of repeated sprint exercise were moderately negative correlated (r = -0.63). Additionally, subjects were able to accurately assess level of recovery using the PRS scale indicated by correspondence with negative and positive changes in total sprint time relative to their previous session. The ability to detect changes in performance using a noninvasive psychobiological tool to identify differences in performance was independent of other psychological and physiological markers measured during testing, because there were no differences (p > 0.05) among ratings of perceived exertion (RPE), heart rate, blood lactate concentration, or session RPE values among any of the performance trials. Although further study is needed, current results indicate a subjective approach may be an effective means for assessing recovery from day to day, at least under similar conditions.


Assuntos
Monitorização Fisiológica/métodos , Corrida/fisiologia , Corrida/psicologia , Adulto , Feminino , Indicadores Básicos de Saúde , Frequência Cardíaca/fisiologia , Humanos , Ácido Láctico/sangue , Masculino , Esforço Físico/fisiologia , Adulto Jovem
10.
J Strength Cond Res ; 25(3): 778-86, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20512070

RESUMO

This study examined effects of heat exposure with and without dehydration on repeated anaerobic cycling. Males (n = 10) completed 3 trials: control (CT), water-bath heat exposure (∼39°C) to 3% dehydration (with fluid replacement) (HE), and similar heat exposure to 3% dehydration (DEHY). Hematocrit increased significantly from pre to postheat immersion in both HE and DEHY. Participants performed 6 × 15s cycle sprints (30s active recovery). Mean Power (MP) was significantly lower vs. CT (596 ± 66 W) for DEHY (569 ± 72 W), and the difference approached significance for HE (582 ± 76 W, p = 0.07). Peak Power (PP) was significantly lower vs. CT (900 ± 117 W) for HE (870 ± 128 W) and approached significance for DEHY (857 ± 145 W, p = 0.07). Postsprint ratings of perceived exertion was higher during DEHY (6.4 ± 2.0) and HE (6.3 ± 1.6) than CT (5.7 ± 2.1). Combined heat and dehydration impaired MP and PP (decrements greatest in later bouts) with HE performance intermediate to CT and DEHY.


Assuntos
Desempenho Atlético/fisiologia , Ciclismo/fisiologia , Ingestão de Líquidos , Resposta ao Choque Térmico , Temperatura Alta , Imersão , Adulto , Frequência Cardíaca/fisiologia , Hematócrito , Humanos , Masculino , Adulto Jovem
11.
Percept Mot Skills ; 112(3): 711-25, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21853760

RESUMO

Eating knowledge, nutritional knowledge, and psychological changes among female collegiate dancers were examined before and after a 4-wk. team-centered program on sport nutrition, exercise, and disordered eating consequences. Collegiate female dancers from two NCAA Division I institutions participated in a control (n = 19; M age = 19.1 yr., SD = 1.0) or intervention (n = 21; M age = 19.2 yr., SD = 1.2) group. Measures were administered to both groups before and after intervention to assess eating disorders, depression, and nutritional and disordered eating knowledge. There was a statistically significant increase in scores on nutritional and overall eating disorder knowledge in the intervention group compared to the control group. Mean scores on depression, drive for thinness, body dissatisfaction, and maturity fears decreased in the intervention group.


Assuntos
Dança/psicologia , Transtornos da Alimentação e da Ingestão de Alimentos/prevenção & controle , Processos Grupais , Educação em Saúde , Conhecimentos, Atitudes e Prática em Saúde , Serviços de Saúde Escolar , Identificação Social , Adolescente , Imagem Corporal , Mecanismos de Defesa , Transtornos da Alimentação e da Ingestão de Alimentos/diagnóstico , Transtornos da Alimentação e da Ingestão de Alimentos/psicologia , Feminino , Humanos , Inventário de Personalidade/estatística & dados numéricos , Psicometria , Autoimagem , Adulto Jovem
12.
Percept Mot Skills ; 112(3): 951-8, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21853781

RESUMO

Knowledge of eating disorders, confidence in knowledge, and attendance of eating disorder educational programs were assessed among NCAA Division I and II university administrators (n = 61), coaches (n = 44), and dancers (n = 53). A questionnaire assessed knowledge in 5 domains: etiology, signs and symptoms, management and treatment, risk factors, and prevention and education. Overall, dancers' knowledge and previous attendance were significantly lower than administrators' and coaches'. There was inconsistency between participants' confidence in answers and the correctness of their answers. Education is necessary for improving knowledge and reducing risky behaviors in auxiliary dancers.


Assuntos
Pessoal Administrativo , Dança/psicologia , Transtornos da Alimentação e da Ingestão de Alimentos/psicologia , Educação em Saúde , Conhecimentos, Atitudes e Prática em Saúde , Educação Física e Treinamento , Instituições Acadêmicas , Esportes/psicologia , Estudantes/psicologia , Adolescente , Imagem Corporal , Feminino , Inquéritos Epidemiológicos , Humanos , Capacitação em Serviço , Magreza/psicologia , Adulto Jovem
13.
Eur J Appl Physiol ; 109(2): 259-67, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20066432

RESUMO

This study examined effects of dehydration on a full body resistance exercise workout. Ten males completed two trials: heat exposed (with 100% fluid replacement) (HE) and dehydration (approximately 3% body mass loss with no fluid replacement) (DEHY) achieved via hot water bath (approximately 39 degrees C). Following HE and DEHY, participants performed three sets to failure (using predetermined 12 repetition maximum) of bench press, lat pull down, overhead press, barbell curl, triceps press, and leg press with a 2-min recovery between each set and 2 min between exercises. A paired t test showed total repetitions (all sets combined) were significantly lower for DEHY: (144.1 +/- 26.6 repetitions) versus HE: (169.4 +/- 29.1 repetitions). ANOVAs showed significantly lower repetitions (approximately 1-2 repetitions on average) per exercise for DEHY versus HE (all exercises). Pre-set rate of perceived exertion (RPE) and pre-set heart rate (HR) were significantly higher [approximately 0.6-1.1 units on average in triceps press, leg press, and approached significance in lat pull down (P = 0.14) and approximately 6-13 b min(-1) on average in bench press, lat pull down, triceps press, and approached significance for overhead press (P = 0.10)] in DEHY versus HE. Session RPE difference approached significance (DEHY: 8.6 +/- 1.9, HE: 7.4 +/- 2.3) (P = 0.12). Recovery HR was significantly higher for DEHY (116 +/- 15 b min(-1)) versus HE (105 +/- 13 b min(-1)). Dehydration (approximately 3%) impaired resistance exercise performance, decreased repetitions, increased perceived exertion, and hindered HR recovery. Results highlight the importance of adequate hydration during full body resistance exercise sessions.


Assuntos
Desidratação/fisiopatologia , Exercício Físico/fisiologia , Frequência Cardíaca , Esforço Físico , Treinamento Resistido , Adulto , Hematócrito , Humanos , Masculino , Volume Plasmático , Adulto Jovem
14.
J Strength Cond Res ; 24(12): 3396-403, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21088551

RESUMO

The purpose of the study was to evaluate the effects of regular warm-up, and upper-body vibration (UBV), or UBV+ short warm-up on swimming performance in Masters Swimmers. Six women and 4 men, mean age 35 ± 9 years, active master swimmers volunteered to participate in the study. Participants were assigned to complete 1 of 3 warm-up types: regular, UBV-only, or UBV + short, rest for 3 minutes, and then completed a 50-yd (45.7 m) freestyle maximal performance time trial. The UBV treatment consisted of 5 minutes of upper-body vibration with a frequency of 22 Hz. Rating of perceived exertion (RPE) and heart rate (HR) were measured post warm-up and post 50-yd time trial. No significant mean differences (p = 0.56) were found among regular, UBV-only, or UBV + short warm-ups for 50-yd freestyle time (29.1 ± 3.36, 28.9 ± 3.39, and 29.1 ± 3.55 seconds, respectively). Individual data indicated that 40% (4/10) of the swimmers swam their fastest with UBV-only and 20% (2/10) with UBV + short warm-up compared to 40% (4/10) with regular warm-up. The RPE pre and post warm-ups did not differ significantly (p = 0.059 and p = 0.216, respectively). A significantly higher (p = 0.023) HR was observed after regular warm-up compared to UBV + short warm-up. Furthermore, HR post 50-yd after regular warm-up was significantly higher compared to UBV-only (p = 0.005) and UBV + short warm-up (p = 0.013). The findings of the present study indicate that UBV and UBV + short warm-up may be considered as addition or an alternative warm-up strategy to regular swimming warm-up, producing reduced cardio stress and perceived effort.


Assuntos
Desempenho Atlético , Natação/fisiologia , Vibração , Adulto , Análise de Variância , Braço/fisiologia , Feminino , Frequência Cardíaca/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Força Muscular/fisiologia , Exercícios de Alongamento Muscular , Esforço Físico/fisiologia
15.
J Occup Environ Hyg ; 7(7): 389-96, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20408017

RESUMO

This study tested the effectiveness of a carbon dioxide cooling device in reducing heat strain for workers in a hot and humid environment. Ten participants completed two trials in an environment of 30 degrees C WBGT (75% relative humidity) with a novel liquid carbon dioxide cooling shirt (CC) or no cooling (NC) in a randomized order. Mean time-weighted workload for each individual equaled 465 W (400 Kcals. h(-1)). In the CC condition, the work time was significantly increased by 32% (97 +/- 36 min) compared with NC (74 +/- 26 min) (p < 0.05). There was no significant difference in mean skin temperature over the trials. Rectal temperature (T(re)) was significantly different after 50 min (p < 0.05). Mean heart rate, the delta T(re) increase rate, and heat storage at 55 min (last point with n = 8) were significantly lower in CC (p < 0.05). Overall heat storage was 54 +/- 41 W and 72 +/- 40 W for CC and NC, respectively (p < 0.05). Participants also indicated favorable subjective responses for CC vs. NC (p < 0.05). These findings suggest that this novel cooling device would effectively attenuate heat strain and increase work productivity for personnel working in a hot and humid environment. Practical aspects of use such as cost, convenience, weight, cooling duration, and rise in ambient CO(2) concentration in confined spaces must also be considered.


Assuntos
Transtornos de Estresse por Calor/prevenção & controle , Temperatura Alta , Esforço Físico , Roupa de Proteção , Temperatura Cutânea , Adulto , Temperatura Corporal , Dióxido de Carbono , Desenho de Equipamento , Frequência Cardíaca , Humanos , Masculino , Estados Unidos
16.
J Phys Act Health ; 17(1): 37-44, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31693994

RESUMO

BACKGROUND: Effective physical activity interventions are needed for children because health behaviors track into adulthood, and risk factors for diseases begin early in life. No study has determined whether an intervention designed using a Community-Based Participatory Research approach can improve moderate to vigorous physical activity (MVPA) and the related psychosocial constructs in underserved children. This study determined whether improvements in MVPA and related psychosocial constructs (self-efficacy, knowledge, beliefs, attitudes, and skills) occurred following a Community-Based Participatory Research intervention in underserved, rural children. It was then determined if these constructs were mediators of MVPA. METHODS: Two fifth-grade classes at a school (n = 19 and n = 20) were randomly assigned to an intervention or comparison group. The intervention group participated in a 4-week intervention designed to improve MVPA (wGT3X-BT accelerometer; ActiGraph, Pensacola, FL) and the related psychosocial constructs (written survey). Groups were assessed prior to and immediately following the intervention. RESULTS: There were no differences at baseline between groups. MVPA (30.0 [4.4] min), knowledge, and skill scores were significantly higher in the intervention group compared with the comparison group at follow-up (P < .05). Knowledge and skills were mediating variables of MVPA. CONCLUSIONS: Priority should be placed on research that determines the sustained impact of similar Community-Based Participatory Research interventions.


Assuntos
Exercício Físico/psicologia , Psicologia/métodos , Criança , Pesquisa Participativa Baseada na Comunidade , Feminino , Comportamentos Relacionados com a Saúde , Humanos , Masculino , Grupos Minoritários , População Rural , Populações Vulneráveis
17.
Psychophysiology ; 57(10): e13633, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32662902

RESUMO

Past research has demonstrated that regular physical activity provides a myriad of physical, mental, and emotional benefits. The decision of whether to partake in physical activity (PA) or remain sedentary appears to be partially influenced by motivational and emotional systems. Research suggests left frontal alpha asymmetry is a neural marker of approach motivation. However, studies have not explored whether habitual levels of PA and sedentary behavior relate to this neurophysiological signal. Across two studies, individuals completed measures of habitual PA and sedentary behavior using the International Physical Activity Questionnaire-Short Form. Then, resting electroencephalography activity was recorded. Results of Study 1 (N = 32, 72% women) indicated that more time spent sitting on both weekdays and weekend days were associated with less left frontal asymmetry (r = -.45, p = .027, and r = -.55, p = .005, respectively). Study 2 recruited a larger sample (N = 96, 31% women) and investigated moderators. Greater levels of moderate (r = .27) and total (r = .29) PA were associated with greater left frontal asymmetry (ps < .05), and the relationship between sedentary behavior and less left frontal asymmetry was moderated by sex (weekday: ß = .62, p = .011; weekend day: ß = .41, p = .034). Our results suggest that left frontal asymmetry may be a novel neurophysiological marker for PA and sedentary behavior.


Assuntos
Eletroencefalografia , Exercício Físico/fisiologia , Lobo Frontal/fisiologia , Lateralidade Funcional/fisiologia , Comportamento Sedentário , Adolescente , Adulto , Biomarcadores , Feminino , Humanos , Masculino , Fatores de Tempo , Adulto Jovem
18.
J Strength Cond Res ; 22(6): 1950-7, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18824931

RESUMO

This study compared independent effects of caffeine and aspirin on muscular endurance (repetitions), heart rate (HR), perceived exertion (RPE), and perceived pain index (PPI) during light resistance training bouts performed to volitional failure. It was hypothesized that the hypoalgesic properties of these ergogenic aids would decrease pain perception and potentially result in enhanced performance. College-aged men (n = 15) participated in a within-subjects, double-blind study with three independent, counterbalanced sessions wherein aspirin (10 mg x kg(-1)), caffeine (6 mg x kg(-1)), or matched placebo were ingested 1 hour before exercise, and RPE, HR, PPI, and repetitions (per set and total per exercise) were recorded at 100% of individual, predetermined, 12-repetition maximum for leg extensions (LE) and seated arm curls (AC). Repeated-measures analyses of variance were used for between-trial comparisons. Caffeine resulted in significantly greater (p < 0.05) HR (LE and AC), total repetitions (LE), and repetitions in set 1 (LE and AC) compared with aspirin and placebo. Aspirin resulted in significantly higher PPI in set 1 (LE). In LE, 47% of participants' performance exceeded the predetermined effect size (>or= 5 repetitions) for total repetitions, with 53% exceeding the effect size (>or= 2 repetitions) for repetitions in set 1 with caffeine (vs. placebo). In AC, 53% (total repetitions) and 47% (set 1 repetitions) of participants exceeded effect sizes with caffeine (vs. placebo), with only 13% experiencing decrements in performance (total repetitions). Aspirin also produced a higher PPI and RPE overall and in set 1 (vs. placebo). This study demonstrates that caffeine significantly enhanced resistance training performance in LE and AC, whereas aspirin did not. Athletes may improve their resistance training performance by acute ingestion of caffeine. As with most ergogenic aids, our analyses indicate that individual responses vary greatly.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Aspirina/farmacologia , Cafeína/farmacologia , Estimulantes do Sistema Nervoso Central/farmacologia , Resistência Física/efeitos dos fármacos , Treinamento Resistido/métodos , Adulto , Método Duplo-Cego , Frequência Cardíaca/efeitos dos fármacos , Humanos , Masculino , Limiar da Dor/efeitos dos fármacos , Esforço Físico/efeitos dos fármacos
19.
Int J Exerc Sci ; 11(4): 479-492, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29541333

RESUMO

The purpose was to determine if pull-up performance was affected by the use of chalk (100% magnesium carbonate) during open-handed and pinch grip weight-assisted pull-ups (WAPU) in recreationally-trained rock climbers. Furthermore, the reliability of open-handed and pinch grip WAPU was also investigated. Recreationally-active volunteers (n = 9) completed six counterbalanced trials. Participants used chalk during four trials to determine the reliability (test-retest) of the open-handed and pinch grips. While two of the six trials were used to determine if open-handed and pinch grip WAPU performance was affected without using chalk. Three of the six trials included one set of open-handed WAPU, while the remaining trails included one set of pinch grip WAPU. Sets were performed until failure and consisted of either the open-handed or pinch grip pull-ups assisted by a 50% reduction of body weight. Heart rate, ratings of perceived exertion, perceived recovery scale and session-RPE were not significantly different (p > 0.05) among trials. Intraclass correlations (ICC's) for test-retest of the open-handed (R = 0.99) and pinch grip (R = 0.96) WAPU evidenced reliable values. When compared to the non-chalked trials, chalk improved both openhanded (mean = 22.8 ± 4.53 vs. mean no chalk = 19.7 ± 4.39 reps; p = 0.006,) and pinch grip (mean = 14.4 ± 4.47 vs. mean no chalk = 9.1 ± 4.83 reps; p = 0.007) WAPU. ICC's indicated a reliable measurement, while chalk improved performance for both open-handed and pinch grip WAPU when compared to no chalk trials.

20.
J Sports Sci Med ; 2(4): 151-7, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24688276

RESUMO

The primary objective of this study was to assess the efficacy of measuring both aerobic and anaerobic power in a 60-second, maximal effort test. It was hypothesized that oxygen consumption increases rapidly during maximal effort and maximal oxygen consumption (VO2 max) may be reached in one minute. Fifteen United States Cycling Federation competitive cyclists performed the following tests: 1) practice 60-second maximal exertion test; 2) standard incremental workload VO2 max test; 3) Wingate anaerobic power test (WAT); 4) VO2 measured during 60-second maximal exertion test (60-SEC); and 5) VO2 measured during 75-second maximal exertion test (75-SEC). All tests were performed on an electrically-braked cycle ergometer. Hydrostatic weighing was performed to determine percent body fat. Peak oxygen consumption values for the 60-SEC (53.4 ml·kg(-1)·min(-1), 92% VO2 max), and 75-SEC (52.6 ml·kg(-1)·min(-1), 91% VO2 max) tests were significantly lower than VO2 max (58.1 ml·kg(-1)·min(-1)). During the 75-SEC test, there was no significant difference in percentage VO2max from 30 seconds to 75 seconds, demonstrating a plateau effect. There were no significant differences in peak power or relative peak power between the Wingate, 60-SEC, and 75 SEC tests while, as expected, mean power, relative mean power, and fatigue index were significantly different between these tests. Power measures were highly correlated among all three tests. It was concluded that VO2 max was not attained during either the 60-SEC nor 75-SEC tests. Furthermore, high correlations in power output for WAT, 60-SEC, and 75-SEC precludes the necessity for anaerobic tests longer than the 30-second WAT.

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