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Biomedical subjects

J Buckworth

Publications and source records attributed to J Buckworth.

7 recordsLinked to original sources

Perceived exertion during incremental cycling is not influenced by the Type A behavior pattern.

Recent publications have perpetuated a concern that the Type A Behavior Pattern (TABP) influences ratings of perceived exertion (RPE) during exercise testing. Previous studies of this topic used the Jenkins Activity Survey (JAS) which lacks validity for predicting the criterion Structured Interview (SI) for TABP and used exercise protocols that were unstandardized or yielded results that were uninterpretable for clinical exercise prescription. We used the SI to classify 44 normotensive men (18-35 y) according to TABP and compared their RPE during an incremental cycling test to peak oxygen uptake (VO2peak). Groups did not differ on maximal test performance or RPE at any stage of the test, even after adjusting RPE for small group variations in % VO2peak and ventilatory equivalent for oxygen, which are strong correlates of RPE during incremental exercise. The findings agree with our prior report [14] that no relationship existed between RPE and several self-report measures of TABP. We conclude that there is no empirical basis for the view that the Type A Behavior Pattern affects cycling performance or ratings of perceived exertion during standard exercise testing in young white men.

Adolescent↗

Exercise training and smoking cessation as the cornerstones of managing claudication.

Based on research, the classic recommendation to prevent progression of lower extremity peripheral arterial disease (PAD) is "start exercising and stop smoking." Unfortunately, a paramount problem for clinicians is motivating targeted individuals to begin and adhere to an exercise regimen and quit smoking. The purpose of this review is to provide the most current information regarding exercise training and smoking cessation. It is hoped that this article will help health care professionals present accurate information to their patients with PAD, address the difficulties in lifestyle change, and intervene effectively.

Exercise Therapy↗

Characteristics of exercise behavior among college students: application of social cognitive theory to predicting stage of change.

BACKGROUND: Young adulthood is characterized by a steep decline in the level of physical activity, but few theory-based studies have examined characteristics associated with regular exercise in this population. This study applied Social Cognitive Theory (SCT) and the Stages of Change Model (SCM) to determine personal, behavioral, and environmental characteristics associated with exercise behavior and intentions among undergraduate university students. METHODS: A random sample of 937 undergraduate students (mean age 22.0 +/- 5.6 years; 84.7% ages 17-24 years) enrolled at a large Midwestern university completed a mailed questionnaire. Valid and reliable instruments were used to measure personal, behavioral, and environmental variables based on the SCT that were hypothesized to influence stage of exercise behavior change. Multivariate discriminant analysis was used to determine associations among these variables with stage of exercise behavior change. RESULTS: Exercise self-efficacy, physical activity history, and nonexercise estimation of aerobic capacity were significant predictors of the stage of exercise behavior change for both males and females. Among females, exercise self-efficacy (P < 0.001) and family social support (P < 0. 001) for physical activity were the best predictors of stage of exercise behavior change. Friend social support (P < 0.001), physical activity history (P < 0.001), and exercise self-efficacy (P < 0.001) were significant predictors of stage of exercise behavior change among males. CONCLUSIONS: The SCT framework predicted stage of exercise behavior change as defined by the SCM. Exercise self-efficacy was associated with exercise stage, but the source of significant social support (family versus friends) was different for males and females.

Adolescent↗

Increased finger arterial blood pressure after exercise detraining in women with parental hypertension: autonomic tasks.

The effects of exercise detraining on resting finger arterial blood pressure (BP), the carotid-cardiac vagal baroreflex, and BP and heart rate (HR) responses to mental arithmetic and forehead cold exposure were studied in young (19 +/- 1.1 years) normotensive women with parental history of hypertension. Following 8 weeks of aerobic exercise for 25 min, 3 days week-1 at an intensity of 60% VO2peak, subjects ceased training for 6-8 weeks. After detraining, VO2peak (mL kg-1 min-1) was reduced by 11.5% (41.1 +/- 6.9 to 36.4 +/- 4.8) coincident with an approximately equal to 10% increase in submaximal exercise heart rate. Responses to the laboratory tasks were then compared. Detraining was accompanied by increases (P < 0.05) in resting systolic (SBP) (113.6 +/- 8.9 to 121.2 +/- 9.0), diastolic (DBP) (63.0 +/- 8.4 to 68.3 +/- 6.8), and mean arterial (MAP) (78.7 +/- 8.4 to 84.2 +/- 7.3) BP (mmHg). None of the above changes occurred in sedentary matched-control subjects. Systolic blood pressure was elevated during forehead cold exposure and MAP was elevated during mental arithmetic after detraining, but the rates of response and recovery for SBP, DBP and MAP were not altered by detraining. Despite higher submaximal exercise HR after detraining, HR responses to autonomic challenges, including the carotid-cardiac vagal baroreflex, were unchanged between training and detraining. Our results indicate that exercise detraining increases resting finger arterial BP in young normotensive women at risk for hypertension with no effects on the rate of response or recovery of heart rate and BP during autonomic tasks known to elicit sympathetic and carotid-cardiac vagal activities in this population. The use of auscultatory brachial artery pressures in a similar study of women diagnosed with hypertension will clarify the clinical meaning of our findings.

Adolescent↗

Increasing physical activity: a quantitative synthesis.

National policy for increasing leisure physical activity in the United States is impeded by a poor understanding of interventions that can be implemented by community and clinical medicine. To clarify the literature in this area, we conducted a quantitative, meta analysis of 127 studies that examined the efficacy of interventions for increasing physical activity among approximately 131,000 subjects in community, worksite, school, home, and health care settings; 445 effects were expressed as a Pearson correlation coefficient (r) and examined as they varied according to moderating variables important for community and clinical intervention. The mean effect was moderately large, r = 0.34, approximating three-fourths of a standard deviation or an increase in binomial success rate from 50% to 67%. The estimated population effect weighted by sample size was larger, r = 0.75, approximating 2 standard deviations or increased success to 88%. Contrasts between levels of independent moderating variables indicated that effects weighted by sample size were larger when the interventions: 1) employed the principles of behavior modification, 2) used a mediated delivery, 3) targeted groups, 4) of combined ages, 5) sampled apparently healthy people, or 6) measured active leisure, of 7) low intensity, 8) by observation. Independently of sample size, effects were larger when interventions 1) used behavior modification, 2) employed a preor quasi-experimental design, or 3) were of short duration, regardless of features of the people, setting, or physical activity. Our results show that physical activity can be increased by intervention. The optimal ways for selecting intervention components, settings, and population segments to maintain increases in physical activity and the relative contributions by community and clinical medicine toward successful physical activity intervention require experimental confirmation, warranting accelerated attention in clinical trials.

Exercise↗

Autonomic responses of women with parental hypertension. Effects of physical activity and fitness.

We studied the moderating effects of cardiorespiratory fitness and physical activity on heart rate and blood pressure responses to psychophysiological stressors and the carotid-cardiac baroreflex in young normotensive women with a parental history of hypertension (n = 31). Testing occurred during the follicular menstrual phase. Subjects were divided into high versus moderate (46.6 +/- 6.5 versus 35.9 +/- 1.9 mL.kg-1.min-1) VO2peak and high versus moderate (1217.7 +/- 98.4 versus 1015.5 +/- 49.4 J.kg-1.wk-1) physical activity groups. The groups did not differ in heart rate or blood pressure responses to mental arithmetic or the cold-face test. However, the highly fit women had longer maximal R-R intervals compared with the moderately fit women when the carotid-cardiac baroreflex was stimulated by negative pressures applied to the neck during resting conditions (P < .01). The carotid-cardiac baroreflex was attenuated during mental arithmetic compared with rest in both the moderately fit and moderately active women but not in the highly fit and highly active groups. We find no evidence that aerobic fitness reduces sympathetic responses to laboratory stressors in young women with parental hypertension. Our findings are consistent with greater parasympathetic tone during sympathetic challenge for the highly fit and highly active subjects. Clarification of autonomic balance during carotid baroreflex stimulation at rest and during sympathetic challenge after exercise training would provide important information regarding mechanisms that regulate cardiovascular responses to autonomic challenge in women at risk for hypertension.

Adult↗