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1.
Contemp Clin Trials ; 141: 107533, 2024 06.
Artigo em Inglês | MEDLINE | ID: mdl-38621517

RESUMO

BACKGROUND: Midlife hypertension is associated with cognitive decline and Alzheimer's disease and related dementia (ADRD), suggesting that blood pressure control may be a therapeutic target for dementia prevention. Given excess hypertension in non-Hispanic Black (NHB) adults, blood pressure control may also reduce ADRD disparities. We describe a pilot randomized controlled trial (RCT) to evaluate the feasibility and preliminary efficacy of a multicomponent lifestyle-based intervention versus enhanced usual care on cognition among middle-aged NHB adults. METHODS AND STUDY DESIGN: The Food Resources and Kitchen Skills plus Aerobic Training (FoRKS+) study is a 2-arm, single-blinded trial that compares those receiving the FoRKS+ program (target N = 64) versus those receiving enhanced usual care (target N = 64) in local federally-qualified health centers. Key eligibility criteria include self-identified NHB adults between ages 35-75 with a mean systolic blood pressure ≥ 130 mm/Hg obtained from 24-h ambulatory blood pressure monitoring. The FoRKS+ program includes 5 weeks of hypertension self-management courses, 11 weeks of nutrition courses, and 12 weeks of aerobic training in dietitian and health coach-led virtual groups. We will collect data on primary cognitive outcomes, feasibility, hypothesized intervention mediators and moderators, and demographic and health covariates at baseline, near intervention weeks 16-, and 28 (primary outcome assessment), and week 52 follow-up. We will use mixed-effects modeling to examine intervention effects on cognition. DISCUSSION: This pilot RCT will examine the feasibility and preliminary effects of a multicomponent lifestyle intervention on cognitive function in NHB adults, which may have implications for reducing health disparities in ADRD.


Assuntos
Negro ou Afro-Americano , Hipertensão , Humanos , Hipertensão/terapia , Pessoa de Meia-Idade , Projetos Piloto , Idoso , Método Simples-Cego , Adulto , Feminino , Masculino , Exercício Físico , Culinária/métodos , Pressão Sanguínea , Estilo de Vida
2.
Appl Clin Inform ; 14(1): 37-44, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36351548

RESUMO

BACKGROUND: Hypoglycemia (HG) causes symptoms that can be fatal, and confers risk of dementia. Wearable devices can improve measurement and feedback to patients and clinicians about HG events and risk. OBJECTIVES: The aim of the study is to determine whether vulnerable older adults could use wearables, and explore HG frequency over 2 weeks. METHODS: First, 10 participants with diabetes mellitus piloted a continuous glucometer, physical activity monitor, electronic medication bottles, and smartphones facilitating prompts about medications, behaviors, and symptoms. They reviewed graphs of glucose values, and were asked about the monitoring experience. Next, a larger sample (N = 70) wore glucometers and activity monitors, and used the smartphone and bottles, for 2 weeks. Participants provided feedback about the devices. Descriptive statistics summarized demographics, baseline experiences, behaviors, and HG. RESULTS: In the initial pilot, 10 patients aged 50 to 85 participated. Problems addressed included failure of the glucometer adhesive. Patients sought understanding of graphs, often requiring some assistance with interpretation. Among 70 patients in subsequent testing, 67% were African-American, 59% were women. Nearly one-fourth (23%) indicated that they never check their blood sugars. Previous HG was reported by 67%. In 2 weeks of monitoring, 73% had HG (glucose ≤70 mg/dL), and 42% had serious, clinically significant HG (glucose under 54 mg/dL). Eight patients with HG also had HG by home-based blood glucometry. Nearly a third of daytime prompts were unanswered. In 24% of participants, continuous glucometers became detached. CONCLUSION: Continuous glucometry occurred for 2 weeks in an older vulnerable population, but devices posed wearability challenges. Most patients experienced HG, often serious in magnitude. This suggests important opportunities to improve wearability and decrease HG frequency among this population.


Assuntos
Diabetes Mellitus , Hipoglicemia , Dispositivos Eletrônicos Vestíveis , Humanos , Feminino , Idoso , Masculino , Glicemia , Automonitorização da Glicemia , Pacientes Ambulatoriais , Hipoglicemia/diagnóstico , Hipoglicemia/epidemiologia , Glucose
4.
Obes Sci Pract ; 8(2): 153-163, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35388340

RESUMO

Objective: One path to improving weight management may be to lessen the self-control burden of physical activity and healthier food choices. Opportunities to lessen the self-control burden might be uncovered by assessing the spatiotemporal experiences of individuals in daily context. This report aims to describe the time, place, and social context of eating and drinking and 6-month weight change among 209 midlife women (n = 113 African-American) with obesity receiving safety-net primary care. Methods: Participants completed baseline and 6-month weight measures, observations and interviews regarding obesogenic cues in the home environment, and up to 12 ecological momentary assessments (EMA) per day for 30 days inquiring about location, social context, and eating and drinking. Results: Home was the most common location (62%) at times of EMA notifications. Participants reported "yes" to eating or drinking at the time of nearly one in three (31.1% ± 13.2%) EMA notifications. Regarding social situations, being alone was significantly associated with less frequent eating and drinking (OR = 0.75) unless at work in which case being alone was significantly associated with a greater frequency of eating or drinking (OR = 1.43). At work, eating was most common late at night, whereas at home eating was most frequent in the afternoon and evening hours. However, eating and drinking frequency was not associated with 6-month weight change. Conclusions: Home and work locations, time of day, and whether alone may be important dimensions to consider in the pursuit of more effective weight loss interventions. Opportunities to personalize weight management interventions, whether digital or human, and lessen in-the-moment self-control burden might lie in identifying times and locations most associated with caloric consumption.Clinical trial registration: NCT03083964 in clinicaltrials.gov.

5.
J Psychosom Res ; 131: 109970, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-32088427

RESUMO

OBJECTIVE: We examined whether total depressive symptoms and symptom clusters predicted behavioral weight loss attendance among economically disadvantaged adults in a randomized controlled trial. METHODS: 150 adults with obesity were randomized to 12 months of in-person, video conference, or enhanced usual care weight loss groups. We categorized percent session attendance in the intervention arms into three levels: no attendance, poorer attendance, and better attendance. RESULTS: Higher baseline Patient Health Questionnaire-8 (PHQ-8) score was associated with a greater odds of being in the poorer versus better attendance group (OR = 1.94, 95% CI: 1.02-3.69, p = .04). A similar relationship between PHQ-8 score and odds of being in the no attendance versus better attendance group was observed but was not statistically significant (OR = 1.63, 95% CI: 0.94-2.81, p = .08). Both cognitive/affective and somatic clusters contributed to the depressive symptoms-attendance relationships. CONCLUSION: Greater depressive symptoms at the start of a behavioral weight loss program may predict poorer subsequent session attendance. Screening for and addressing depression may improve intervention uptake. ClinicalTrials.gov Identifier: NCT02057952.

6.
JMIR Mhealth Uhealth ; 7(4): e10894, 2019 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-30942698

RESUMO

BACKGROUND: Ecological momentary assessment (EMA) can be a useful tool for collecting real-time behavioral data in studies of health and health behavior. However, EMA administered through mobile technology can be burdensome, and it tends to suffer from suboptimal user engagement, particularly in low health-literacy populations. OBJECTIVE: This study aimed to report a case study involving the design and evaluation of a mobile EMA tool that supports context-sensitive EMA-reporting of location and social situations accompanying eating and sedentary behavior. METHODS: An iterative, user-centered design process with obese, middle-aged women seeking care in a safety-net health system was used to identify the preferred format of self-report measures and the look, feel, and interaction of the mobile EMA tool. A single-arm feasibility field trial with 21 participants receiving 12 prompts each day for momentary self-reports over a 4-week period (336 total prompts per participant) was used to determine user satisfaction with interface quality and user engagement, operationalized as response rate. A second trial among 38 different participants randomized to receive or not to receive a feature designed to improve engagement was conducted. RESULTS: The feasibility trial results showed high interface satisfaction and engagement, with an average response rate of 50% over 4 weeks. Qualitative feedback pointed to the need for auditory alerts. We settled on 3 alerts at 10-min intervals to accompany each EMA-reporting prompt. The second trial testing this feature showed a statistically significant increase in the response rate between participants randomized to receive repeat auditory alerts versus those who were not (60% vs 40%). CONCLUSIONS: This paper reviews the design research and a set of design constraints that may be considered in the creation of mobile EMA interfaces personalized to users' preferences. Novel aspects of the study include the involvement of low health-literacy adults in design research, the capture of data on time, place, and social context of eating and sedentary behavior, and reporting prompts tailored to an individual's location and schedule. TRIAL REGISTRATION: ClinicalTrials.gov NCT03083964; https://clinicaltrials.gov/ct2/show/NCT03083964.


Assuntos
Participação do Paciente , Satisfação Pessoal , Autorrelato/normas , Adulto , Avaliação Momentânea Ecológica/estatística & dados numéricos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Autorrelato/estatística & dados numéricos , Inquéritos e Questionários
7.
Clin Interv Aging ; 12: 1141-1149, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28769559

RESUMO

BACKGROUND: Resistance exercise is effective to increase muscle strength for older adults; however, its effect on the outcome of activities of daily living is often limited. The purpose of this study was to examine whether 3-Step Workout for Life (which combines resistance exercise, functional exercise, and activities of daily living exercise) would be more beneficial than resistance exercise alone. METHODS: A single-blind randomized controlled trial was conducted. Fifty-two inactive, community-dwelling older adults (mean age =73 years) with muscle weakness and difficulty in activities of daily living were randomized to receive 3-Step Workout for Life or resistance exercise only. Participants in the 3-Step Workout for Life Group performed functional movements and selected activities of daily living at home in addition to resistance exercise. Participants in the Resistance Exercise Only Group performed resistance exercise only. Both groups were comparable in exercise intensity (moderate), duration (50-60 minutes each time for 10 weeks), and frequency (three times a week). Assessment of Motor and Process Skills, a standard performance test on activities of daily living, was administered at baseline, postintervention, and 6 months after intervention completion. RESULTS: At postintervention, the 3-Step Workout for Life Group showed improvement on the outcome measure (mean change from baseline =0.29, P=0.02), but the improvement was not greater than the Resistance Exercise Only Group (group mean difference =0.24, P=0.13). However, the Resistance Exercise Only Group showed a significant decline (mean change from baseline =-0.25, P=0.01) 6 months after the intervention completion. Meanwhile, the superior effect of 3-Step Workout for Life was observed (group mean difference =0.37, P<0.01). CONCLUSION: Compared to resistance exercise alone, 3-Step Workout for Life improves the performance of activities of daily living and attenuates the disablement process in older adults.


Assuntos
Atividades Cotidianas , Vida Independente , Condicionamento Físico Humano/métodos , Idoso , Idoso de 80 Anos ou mais , Exercício Físico/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Força Muscular/fisiologia , Treinamento Resistido/métodos , Método Simples-Cego , Resultado do Tratamento
8.
Pain ; 158(3): 383-390, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28187102

RESUMO

Older adults compared with younger adults are characterized by greater endogenous pain facilitation and a reduced capacity to endogenously inhibit pain, potentially placing them at a greater risk for chronic pain. Previous research suggests that higher levels of self-reported physical activity are associated with more effective pain inhibition and less pain facilitation on quantitative sensory tests in healthy adults. However, no studies have directly tested the relationship between physical activity behavior and pain modulatory function in older adults. This study examined whether objective measures of physical activity behavior cross-sectionally predicted pain inhibitory function on the conditioned pain modulation (CPM) test and pain facilitation on the temporal summation (TS) test in healthy older adults. Fifty-one older adults wore an accelerometer on the hip for 7 days and completed the CPM and TS tests. Measures of sedentary time, light physical activity (LPA), and moderate to vigorous physical activity (MVPA) were obtained from the accelerometer. Hierarchical linear regressions were conducted to determine the relationship of TS and CPM with levels of physical activity, while controlling for demographic, psychological, and test variables. The results indicated that sedentary time and LPA significantly predicted pain inhibitory function on the CPM test, with less sedentary time and greater LPA per day associated with greater pain inhibitory capacity. Additionally, MVPA predicted pain facilitation on the TS test, with greater MVPA associated with less TS of pain. These results suggest that different types of physical activity behavior may differentially impact pain inhibitory and facilitatory processes in older adults.


Assuntos
Exercício Físico/fisiologia , Avaliação Geriátrica , Limiar da Dor/fisiologia , Dor/diagnóstico , Dor/fisiopatologia , Actigrafia , Idoso , Catastrofização/psicologia , Estudos Transversais , Feminino , Previsões , Humanos , Hiperalgesia/fisiopatologia , Masculino , Pessoa de Meia-Idade , Dor/psicologia , Medição da Dor , Estimulação Física/efeitos adversos , Escalas de Graduação Psiquiátrica , Análise de Regressão , Comportamento Sedentário , Autorrelato , Fatores Sexuais
10.
Clin Med Insights Womens Health ; 9(Suppl 1): 85-93, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27840584

RESUMO

BACKGROUND: Obese black women enrolled in weight loss interventions experience 50% less weight reduction than obese white women. This suggests that current weight loss strategies may increase health disparities. OBJECTIVE: We evaluated the feasibility of identifying daily contextual factors that may influence obesity. METHODS: In-home interviews with 16 obese (body mass index ≥ 30) black and white urban poor women were performed. For 14 days, ecological momentary assessment (EMA) was used to capture emotion and social interactions every other day, and day reconstruction method surveys were used the following day to reconstruct the context of the prior day's EMA. RESULTS: Factors included percentage of participants without weight scales (43.8%) or fitness equipment (68.8%) in the home and exposed to food at work (55.6%). The most frequently reported location, activity, and emotion were home (19.4 ± 8.53), working (7.1 ± 8.80), and happy (6.9 ± 10.03), respectively. CONCLUSION: Identifying individual contexts may lead to valuable insights about obesogenic behaviors and new interventions to improve weight management.

11.
Ethn Dis ; 26(2): 197-204, 2016 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-27103770

RESUMO

C-reactive protein (CRP) is a risk factor for cardiovascular disease and mortality; it is known to be positively associated with obesity but there is some evidence that this association differs by race or sex. We used nationally representative data of adults aged >50 years to investigate sex and race modifiers of the associations between obesity and CRP in non-Hispanic White males (n=3,517) and females (n=4,658), and non-Hispanic Black males (n=464) and females (n=826). Using multiple linear regression models with the natural logarithm of CRP as the dependent variable, we sequentially included body mass index (BMI), a body shape index (ABSI), and socioeconomic, health and health behavior covariates in the model. The association between BMI and CRP was significantly stronger in females than males. Obese White females had mean CRP values slightly above 3 mg/liter (vs 2 for White males) and Black females had mean CRP values >4 mg/liter (vs 3 for Black males). More than 50% of Black females in the United States have obesity. Continued research into racial and sex differences in the relationship between obesity, inflammation, and health risks may ultimately lead to more personalized weight loss recommendations.


Assuntos
Proteína C-Reativa/análise , Doenças Cardiovasculares/etnologia , Obesidade/etnologia , Adulto , Negro ou Afro-Americano , Idoso , Índice de Massa Corporal , Doenças Cardiovasculares/epidemiologia , Etnicidade , Feminino , Comportamentos Relacionados com a Saúde , Humanos , Inflamação , Masculino , Pessoa de Meia-Idade , Obesidade/sangue , Grupos Raciais , Fatores de Risco , Estados Unidos , População Branca
12.
Am J Health Behav ; 39(1): 34-42, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25290595

RESUMO

OBJECTIVE: To explore differences between Blacks and Whites in perceived influences on weight-related behaviors among obese urban poor women. METHODS: Participants (N = 27) received physician referrals to a weight loss program located in Federally Qualified Health Centers and either never attended or stopped attending. We conducted in-depth, in home interviews using a script informed by focus groups, pilot discussions, and the theory of planned behavior (TPB) to learn about participants' weight loss attitudes, social forces and perceived behavioral control. RESULTS: White women reported having more social support and social pressure for weight management activities. Black women reported eating for positive reasons whereas white women associated eating with negative emotions. CONCLUSION: Social networks and emotions may be critical factors in weight management and lifestyle program participation.


Assuntos
População Negra/psicologia , Conhecimentos, Atitudes e Prática em Saúde , Pobreza/psicologia , Controles Informais da Sociedade , População Urbana , Redução de Peso , População Branca/psicologia , Adulto , Feminino , Humanos , Pessoa de Meia-Idade , Obesidade/psicologia
13.
Am J Health Promot ; 29(4): 266-72, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-24670069

RESUMO

PURPOSE: To compare concurrent criterion validity of the Self-Reported Fitness (SRFit) Survey, a new fitness measure, between black and white race, gender, and health literacy groups. DESIGN: Cross-sectional. SETTING: Midwest urban primary care center and commercial fitness center. SUBJECTS: One hundred one black, white, male, and female primary care patients aged ≥40 years. MEASURES: Measures included demographics, the Rapid Estimate of Adult Literacy in Medicine, the SRFit Survey, and the Rikli and Jones Senior Fitness Test battery of physical tests. The BodPod determined percentage of body fat. Body mass index was calculated. ANALYSIS: Concurrent validity was assessed using Pearson and Spearman rank order correlations between corresponding physical tests and SRFit survey items. RESULTS: Correlations between physical tests and SRFit items ranged from r = .52 to .76 (ρ = .41-.85) in males, r = .40 to .79 (ρ = .33-.80) in females, r = .45 to .79 (ρ = .53-.82) in blacks, and r = .49 to .77 (ρ = .33-.82) in whites. Correlations were r = .58 (ρ = .58) to r = .77 (ρ = .79) in persons with low health literacy and r = .50 to .79 (ρ = .39-.85) among persons with moderate to high health literacy. CONCLUSION: SRFit shows similar concurrent validity across race, gender, and health literacy subgroups.


Assuntos
Negro ou Afro-Americano , Letramento em Saúde , Aptidão Física , Autorrelato/normas , População Branca , Adulto , Distribuição por Idade , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Distribuição por Sexo
15.
J Phys Act Health ; 11(4): 853-9, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-23676451

RESUMO

BACKGROUND: An accurate physical fitness survey could be useful in research and clinical care. PURPOSE: To estimate the validity and reliability of a Self-Reported Fitness (SRFit) survey; an instrument that estimates muscular fitness, flexibility, cardiovascular endurance, BMI, and body composition (BC) in adults ≥ 40 years of age. METHODS: 201 participants completed the SF-36 Physical Function Subscale, International Physical Activity Questionnaire (IPAQ), Older Adults' Desire for Physical Competence Scale (Rejeski), the SRFit survey, and the Rikli and Jones Senior Fitness Test. BC, height and weight were measured. SRFit survey items described BC, BMI, and Senior Fitness Test movements. Correlations between the Senior Fitness Test and the SRFit survey assessed concurrent validity. Cronbach's Alpha measured internal consistency within each SRFit domain. SRFit domain scores were compared with SF-36, IPAQ, and Rejeski survey scores to assess construct validity. Intraclass correlations evaluated test-retest reliability. RESULTS: Correlations between SRFit and the Senior Fitness Test domains ranged from 0.35 to 0.79. Cronbach's Alpha scores were .75 to .85. Correlations between SRFit and other survey scores were -0.23 to 0.72 and in the expected direction. Intraclass correlation coefficients were 0.79 to 0.93. All P-values were 0.001. CONCLUSION: Initial evaluation supports the SRFit survey's validity and reliability.


Assuntos
Envelhecimento/fisiologia , Índice de Massa Corporal , Inquéritos Epidemiológicos/normas , Resistência Física , Exame Físico , Aptidão Física , Adulto , Idoso , Idoso de 80 Anos ou mais , Composição Corporal , Teste de Esforço , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Autorrelato , Inquéritos e Questionários
16.
Med Sci Sports Exerc ; 44(7): 1388-94, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22297807

RESUMO

UNLABELLED: Physical fitness measures indicate health status, and these can be used to improve management of overall health. PURPOSE: This study aimed to describe the development of a self-reported fitness (SRFit) survey intended to estimate fitness in adults age ≥40 yr across four domains: 1) muscular strength and endurance, 2) cardiovascular fitness, 3) flexibility, and 4) body composition. METHODS: SRFit items were developed from the previously validated Rikli and Jones Senior Fitness Test battery of physical tests. Face-to-face participant interviews were used to refine SRFit item wording. Data from a pilot administration of the SRFit survey were used to guide further revisions of SRFit items. The Senior Fitness Test battery was used to evaluate the four fitness domains. The BodPod was used to measure body composition. Height, weight, and resting blood pressure were measured, and the revised SRFit survey was administered to 108 participants. RESULTS: Forty-five percent of the participants were women and 37% reported being black or in the "other" race category. Mean age was 53.5 ± 8.0 yr and mean body mass index was 30.6 ± 8.8 kg·m(-2). Mean ± SD SRFit summary scores and correlations found between summary and fitness test scores were as follows: upper body strength = 12.8 ± 2.4, r = 0.59, P < 0.001; lower body strength = 12.6 ± 2.6, r = 0.68, P < 0.001; upper body flexibility (left side) = 12.3 ± 2.8, r = 0.47, P < 0.001; upper body flexibility (right side) = 12.4 ± 2.8, r = 0.67, P < 0.001; lower body flexibility = 17.4 ± 3.8, r = 0.55, P < 0.001; cardiovascular endurance = 12.9 ± 2.6, r = 0.66, P < 0.001; body mass index = 7.7 ± 2.23, r = 0.79, P < 0.001; and percent body fat = 7.7 ± 2.2, r = 0.78, P < 0.001. CONCLUSIONS: SRFit survey items in each fitness domain were correlated with analogous Senior Fitness Test items, indicating that participants can accurately use the SRFit survey to self-report physical fitness.


Assuntos
Aptidão Física/fisiologia , Autorrelato/normas , Adulto , Idoso , Envelhecimento , Estudos Transversais , Feminino , Humanos , Indiana , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes
17.
J Health Care Poor Underserved ; 21(2): 617-28, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20453361

RESUMO

Community health centers have the potential to lessen obesity. We conducted a retrospective evaluation of a quality improvement program that included electronic body mass index (BMI) screening with provider referral to an in-clinic lifestyle behavior change counselor with weekly nutrition and exercise classes. There were 26,661 adult patients seen across five community health centers operating the weight management program. There were 23,593 (88%) adult patients screened, and 12,487 (53%) of these patients were overweight or obese (BMI >or=25). Forty percent received a provider referral, 15.6% had program contact, and 2.1% had more than 10 program contacts. A mean weight loss of seven pounds was observed among those patients with more than 10 program contacts. No significant weight change was observed in patients with less contact. Achieving public health impact from guideline recommended approaches to CHC-based weight management will require considerable improvement in patient and provider participation.


Assuntos
Centros Comunitários de Saúde/organização & administração , Programas de Rastreamento/estatística & dados numéricos , Obesidade/terapia , Cooperação do Paciente/estatística & dados numéricos , Encaminhamento e Consulta/estatística & dados numéricos , Adulto , Índice de Massa Corporal , Centros Comunitários de Saúde/normas , Feminino , Comportamentos Relacionados com a Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Avaliação de Programas e Projetos de Saúde , Estudos Retrospectivos , Redução de Peso
18.
Med Sci Sports Exerc ; 38(10): 1762-9, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17019298

RESUMO

PURPOSE: Although running economy (RE) is recognized as an integral component of successful endurance performance and is affected by numerous factors, little is known about the influence of body water loss on RE. This investigation examined the effects of hypohydration (HY) on RE and associated physiological responses. METHODS: Ten highly trained collegiate distance runners (mean +/- SD; age, 20 +/- 3 yr; height, 178.5 +/- 6.3 cm; body mass, 66.7 +/- 5.4 kg; VO2max, 66.5 +/- 4.1 mL x kg(-1) x min(-1)) participated in four experiments on separate days, twice in a euhydrated (EU) and twice in a HY state (-5.5 and -5.7% body mass loss achieved during 24 h). At each hydration level, subjects performed one 10-min treadmill run per day (23 degrees C environment), at either 70% VO2max (EU 70% or HY 70%) or 85% VO2max (EU 85% or HY 85%) in a randomized, repeated-measures design. Cardiopulmonary, metabolic, thermal, hormonal, and perceptual variables were measured. RESULTS: No between-treatment differences existed for RE (EU 70%, 46.3 +/- 3.2; HY 70%, 47.2 +/- 3.8; EU 85%, 58.6 +/- 2.8; HY 85%, 58.9 +/- 4.1 mL x kg(-1) x min(-1)), postexercise plasma lactate concentration (EU 70%, 1.9 +/- 0.6; HY 70%, 1.8 +/- 0.6; EU 85%, 6.5 +/- 3.5; HY 85%, 6.4 +/- 3.5 mmol x L(-1)), or rating of perceived exertion. HY resulted in a greater (P < 0.05 to 0.001) heart rate (HR), rectal temperature, and plasma norepinephrine concentration (NE), concurrent with reduced cardiac output, stroke volume, and respiratory exchange ratio. CONCLUSION: HY did not alter the RE or lactate accumulation of endurance athletes during 10 min of exercise at 70 and 85% VO2max. These findings indicate that HY had no effect on RE, but that it increased physiological strain in a 23 degrees C environment.


Assuntos
Comportamento Competitivo/fisiologia , Desidratação/fisiopatologia , Frequência Cardíaca/fisiologia , Resistência Física/fisiologia , Corrida/fisiologia , Adolescente , Adulto , Circulação Sanguínea , Temperatura Corporal , Água Corporal , Teste de Esforço , Humanos , Masculino , Norepinefrina , Consumo de Oxigênio/fisiologia , Estudos Prospectivos , Inquéritos e Questionários , Fatores de Tempo
19.
Am J Physiol Endocrinol Metab ; 288(5): E868-75, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15598669

RESUMO

Although endogenous and exogenous steroid hormones affect numerous physiological processes, the interactions of reproductive hormones, chronic exercise training, and heat acclimation are unknown. This investigation evaluated the responses and adaptations of 36 inactive females [age 21 +/- 3 (SD) yr] as they undertook a 7- to 8-wk program [heat acclimation and physical training (HAPT)] of indoor heat acclimation (90 min/day, 3 days/wk) and outdoor physical training (3 days/wk) while using either an oral estradiol-progestin contraceptive (ORAL, n = 15), a contraceptive injection of depot medroxyprogesterone acetate (DEPO, n = 7), or no contraceptive (EU-OV, n = 14; control). Standardized physical fitness and exercise-heat tolerance tests (36.5 degrees C, 37% relative humidity), administered before and after HAPT, demonstrated that the three subject groups successfully (P < 0.05) acclimated to heat (i.e., rectal temperature, heart rate) and improved muscular endurance (i.e., sit-ups, push-ups, 4.6-km run time) and body composition characteristics. The stress of HAPT did not disrupt the menstrual cycle length/phase characteristics, ovulation, or plasma hormone concentrations of EU-OV. No between-group differences (P > 0.05) existed for rectal and skin temperatures or metabolic, cardiorespiratory, muscular endurance, or body composition variables. A significant difference post-HAPT in the onset temperature of local sweating, ORAL (37.2 +/- 0.4 degrees C) vs. DEPO (37.7 +/- 0.2 degrees C), suggested that steroid hormones influenced this adaptation. In summary, virtually all adaptations of ORAL and DEPO were similar to EU-OV, suggesting that exogenous reproductive hormones neither enhanced nor impaired the ability of women to complete 7-8 wk of strenuous physical training and heat acclimation.


Assuntos
Adaptação Fisiológica/efeitos dos fármacos , Adaptação Fisiológica/fisiologia , Anticoncepcionais Orais Sintéticos/administração & dosagem , Tolerância ao Exercício/fisiologia , Hormônios Esteroides Gonadais/administração & dosagem , Temperatura Alta , Aptidão Física/fisiologia , Aclimatação/efeitos dos fármacos , Aclimatação/fisiologia , Adulto , Tolerância ao Exercício/efeitos dos fármacos , Feminino , Humanos , Educação Física e Treinamento/métodos , Esforço Físico/efeitos dos fármacos , Esforço Físico/fisiologia
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