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J Larry Durstine

Publications and source records attributed to J Larry Durstine.

13 recordsLinked to original sources
PubMed2006

Circadian variation in swim performance.

Previous findings of time-of-day differences in athletic performance could be confounded by diurnal fluctuations in environmental and behavioral "masking" factors (e.g., sleep, ambient temperature, and energy intake). The purpose of this study was to examine whether there is a circadian rhythm in swim performance that is independent of these masking factors. Experienced swimmers (n = 25) were assessed for 50-55 consecutive hours in the laboratory. The swimmers followed a 3-h "ultra-short" sleep-wake cycle, involving 1 h of sleep in darkness and 2 h of wakefulness in dim light, that was repeated throughout the observation. The protocol distributes behavioral and environmental masking factors equally across the 24-h period. Each swimmer was scheduled to perform six maximal-effort 200-m swim trials that were distributed equally across eight times of day (n = 147 trials). Each trial was separated by 9 h. A cosine fit of intra-aural temperature data established the time of the lowest body temperature (Tmin). Swim performances were z-transformed and compared across the eight times of day and across twelve 2-h intervals relative to Tmin. Analysis of covariance, controlling for trial number, revealed a significant (P < 0.001) pattern in swim performance relative to environmental and circadian times of day. Performance peaked 5-7 h before Tmin (approximately 2300) and was worst from 1 h before to 1 h after Tmin (approximately 0500). Mean swim performance was 169.5 s; circadian variation from peak to worst performance was 5.8 s. These data suggest a circadian rhythm in athletic performance independent of environmental and behavioral masking effects.

Adult↗
PubMed2005

Managing abnormal blood lipids: a collaborative approach.

Current data and guidelines recommend treating abnormal blood lipids (ABL) to goal. This is a complex process and requires involvement from various healthcare professionals with a wide range of expertise. The model of a multidisciplinary case management approach for patients with ABL is well documented and described. This collaborative approach encompasses primary and secondary prevention across the lifespan, incorporates nutritional and exercise management as a significant component, defines the importance and indications for pharmacological therapy, and emphasizes the importance of adherence. Use of this collaborative approach for the treatment of ABL ultimately will improve cardiovascular and cerebrovascular morbidity and mortality.

Adolescent↗
PubMed2005

Influence of cardiorespiratory fitness on the association between C-reactive protein and metabolic syndrome prevalence in racially diverse women.

BACKGROUND: Metabolic syndrome and C-reactive protein (CRP) are independent predictors of cardiovascular disease (CVD) among women. The extent to which cardiorespiratory fitness influences the relationship between CRP and metabolic syndrome is unknown. METHODS AND RESULTS: Cross-sectional associations among fitness, CRP, and metabolic syndrome were examined in 135 African American, Native American, and Caucasian women (55 +/- 11 years, 28 +/- 6 kg/m2). Fitness was quantified with a symptom-limited maximal treadmill exercise test. Plasma CRP concentrations were determined with the Dade-Behring high-sensitivity immunoassay. Metabolic syndrome was defined according to NCEP-ATP III. Metabolic syndrome, CRP, and fitness varied (p < 0.05) by race. Race-adjusted CRP values were directly associated (p < 0.05) with each metabolic syndrome component. After adjusting for age and race, the relative odds of metabolic syndrome was 3.6 (95% CI = 1.5 - 8.4) in women with elevated (> 2.0 mg/L) vs. low CRP. Adjustment for smoking, hormone therapy, body mass index (BMI), and HOMA insulin resistance did not eliminate this association (p < 0.05). The association between CRP and the metabolic syndrome was no longer significant (OR = 1.3, 95% CI = 0.9 - 5.9, p = 0.59) after adjustment for fitness. CONCLUSIONS: Higher cardiorespiratory fitness may be an important consideration in the milieu of vascular inflammation and metabolic syndrome.

Adult↗
PubMed2005

Urban, rural, and regional variations in physical activity.

PURPOSE: There is some speculation about geographic differences in physical activity (PA) levels. We examined the prevalence of physical inactivity (PIA) and whether U.S. citizens met the recommended levels of PA across the United States. In addition, the association between PIA/PA and degree of urbanization in the 4 main U.S. regions (Northeast, Midwest, South, and West) was determined. METHODS: Participants were 178,161 respondents to the 2000 Behavioral Risk Factor Surveillance System (BRFSS). Data from 49 states and the District of Columbia were included (excluding Alaska). States were categorized by urban status according to the U.S. Department of Agriculture. Physical activity variables were those commonly used in national surveillance systems (PIA = no leisure-time PA; and PA = meeting a PA recommendation). RESULTS: Nationally, PA levels were higher in urban areas than in rural areas; correspondingly, PIA levels were higher in rural areas than in urban areas. Regionally, the urban-rural differences were most striking in the South and were, in fact, often absent in other regions. Demographic factors appeared to modify the association. CONCLUSION: The association between PA and degree of urbanization is evident and robust in the South but cannot be generalized to all regions of the United States. For the most part, the Midwest and the Northeast do not experience any relationship between PA and urbanization, whereas, in the West, the trend appears to be opposite of that observed in the South.

Activities of Daily Living↗
PubMed2004

Exercise physiology and its role in clinical sports medicine.

Exercise physiology plays an important role in the practice of clinical sports medicine. Exercise physiology research has identified important effects of exercise on the body's systems, tissues, and cells. Ongoing research is investigating the role of exercise in subcellular, molecular, and chemical processes. Increasingly, sports medicine physicians and other practitioners are using the findings of this research to help athletes achieve peak performance, and nonathletes achieve better health through exercise. Many areas of sports medicine practice, including exercise testing, safety, performance evaluation, correction of training problems, and prevention of problems that affect specific populations (eg, older athletes, women, children), benefit from the application of exercise physiology theory and research. The continued demand for athletes at all levels to be better, faster, and stronger, combined with the national focus on getting all Americans involved in some form of physical activity, will require that sports medicine practitioners and exercise physiologists increasingly work together to optimize sports and exercise performance, health, and safety.

Adult↗
PubMed2003

The hypertriglyceridemic waist phenotype among women.

BACKGROUND: Elevated plasma triglycerides (TG) and waist girth (hypertriglyceridemic waist (HTGW)) has been associated with elevated insulin, small dense low-density lipoprotein (sLDL) particles, and Apo B in men. The HTGW has not been reported for women and the effect of cardiorespiratory fitness ("fitness") on associations between HTGW and coronary risk factors is unknown. PURPOSE: To determine the prevalence of HTGW and the influence of fitness on the relationship between HTGW and coronary risk among 137 healthy women (54+/-9 year; body mass index (BMI)=28+/-6 kg/m(2)). METHODS: HTGW was defined as waist girth >88 cm and TG >150 mg/dl. The metabolic triad was defined as insulin >31 pmol/l, Apo B >69 mg/dl and LDL-C >84 mg/dl. Fitness was assessed with a maximal treadmill exercise test. RESULTS: The sample prevalence of HTGW (n=15) was 11% (95% CI=5.7-16.0%). Apo B (P=0.04) and insulin (P=0.0001) increased across quintiles of waist girth, and LDL-C (P=0.004) increased across quintiles of TG. Metabolic triad prevalence was highest (67%, n=10) among HTGW women and lowest (22%, n=26) among non-HTGW women. A trend for higher coronary heart disease CHD risk factors was observed among HTGW compared with non-HTGW women. Among the HTGW group, a trend for lower CHD risk factors was observed among fit (>or=6.5 METs, n=7) versus unfit women (<6.5 METs, n=8). Sample size limitations prohibited meaningful tests of significant differences in CHD risk factors when stratified simultaneously on HTGW and fitness status. CONCLUSIONS: HTGW is associated with increased coronary risk factors similarly among women as reported for men. Higher fitness may improve the CHD risk profile among women with HTGW.

Apolipoproteins B↗
PubMed2002

Cardiorespiratory fitness and C-reactive protein among a tri-ethnic sample of women.

BACKGROUND: Elevated C-reactive protein (CRP) is associated with increased coronary heart disease (CHD) risk. Cardiorespiratory fitness ("fitness") is related with lower CHD risk; however, its relationship with CRP is relatively unknown. METHODS AND RESULTS: Cross-sectional associations between fitness and plasma CRP were examined among 135 African American (AA), Native American (NA), and Caucasian (CA) women (55+/-11 year; 28+/-6 kg/m2). Fitness was assessed with a maximal treadmill exercise test. Plasma CRP concentrations were determined with the Dade Behring high-sensitivity immunoassay. Geometric mean CRP levels were 0.43, 0.25, and 0.23 mg/dL, and average maximal MET levels of fitness were 7.2, 9.1, and 10 METs for AA, NA, and CA, respectively. CRP decreased across tertiles of fitness (P=0.002), increased across tertiles of BMI (P=0.0007), and varied by race (P=0.002). After adjustment for covariates, lower CRP (P<0.05) was observed across tertiles of fitness among NA and CA, but not AA. Among all women, after adjusting for race and covariates, the odds of high-risk CRP (>0.19 mg/dL) were 0.67 (95% CI=0.19 to 2.4) among fit (>6.5 METs) versus unfit women. CONCLUSIONS: The health benefits from enhanced fitness may have an antiinflammatory mechanism.

Black People↗
PubMed2002

Physical activity and the metabolic syndrome in a tri-ethnic sample of women.

OBJECTIVE: To determine the association of moderate-intensity physical activity (PA), vigorous-intensity PA, and maximal treadmill duration with the metabolic syndrome among African-American (n = 49), Native-American (n = 46), and white (n = 51) women (ages, 40 to 83 years), enrolled in the Cross-Cultural Activity Participation Study. RESEARCH METHODS AND PROCEDURES: The metabolic syndrome was defined as three or more of the following risk factors: waist circumference >88 cm, blood pressure > or =130/85 mm Hg, fasting glucose > or =110 mg/dL, hypertriglyceridemia (> or =150 mg/dL), and high-density lipoprotein-cholesterol <50 mg/dL. PA was determined from detailed PA records that included all PA performed during two consecutive 4-day periods. Maximal treadmill duration was determined from a graded exercise test. Women were categorized into quartiles of moderate-intensity PA, vigorous-intensity PA, and maximal treadmill duration. Multiple logistic regression was used to estimate odds ratios of the metabolic syndrome as a function of the four PA categories, adjusted for age, ethnicity, study site, menopausal status, and use of hormone-replacement therapy. RESULTS: The adjusted odds ratio for the metabolic syndrome was 0.18 (95% confidence interval, 0.33 to 0.90) for women in the highest category of moderate-intensity PA compared with women in the lowest category (p = 0.01 for trend). Similar associations were observed for the metabolic syndrome with vigorous-intensity PA (p = 0.01 for trend) and maximal treadmill duration (p = 0.0004 for trend). DISCUSSION: Higher levels of moderate and vigorous-intensity PA and greater maximal treadmill duration were inversely associated with the metabolic syndrome among an ethnically diverse sample of women.

Adult↗
PubMed2002

Factors influencing health-related quality of life in cardiac rehabilitation patients.

Associations of age, gender, cardiac procedure (coronary artery bypass grafting or percutaneous transluminal coronary angioplasty), risk stratification, and number of comorbidities with health-related quality of life (HRQL) were examined among 217 men and 84 women (mean age, 63+/-11 years) consecutively enrolled in a phase II cardiac rehabilitation program. Female gender and high-risk stratification were independently associated with impaired treatment gains in most areas of HRQL. Older age and having a greater number of comorbidities were also associated with impaired gains in specific areas. HRQL was generally lower at baseline but not post-treatment in coronary artery bypass grafting vs. percutaneous transluminal coronary angioplasty patients. Cardiac rehabilitation patients also had lower HRQL scores than an age-matched, normative sample at baseline (most areas) and post-treatment (mainly on role physical). Findings reinforce the need for cardiac rehabilitation programs to tailor assessments and risk factor modification strategies to patient characteristics associated with low levels of HRQL, especially in women and those with higher risk stratification.

Adult↗
PubMedDate not supplied

In their own voices: definitions and interpretations of physical activity.

Terms such as physical activity, exercise, and leisure are perceived and interpreted differently by people differing in gender, class, and sociocultural factors. We accessed multiple diverse data sources (including qualitative data recently collected in research and evaluation studies) to explore African-American and American Indian women's (age 40+) definitions, meanings, and interpretations of "physical activity". These women reported that physical activity is typically considered to be structured "exercise" and not incidental activities of daily life. The term "leisure" was interpreted from a cultural perspective as being lazy. These women also had difficulty understanding the meaning of "intensity" (e.g., "moderate", "vigorous"). Researchers must acknowledge and understand inconsistencies that arise and how these might influence design of, and responses to, self-report assessment of physical activity.

Adult↗
PubMedDate not supplied

Assessing dietary fat intake in chronic disease rehabilitation programs.

PURPOSE: Previous work has established that the Heart Fit Rx Diet Habits Survey (HFD), formerly the Food Frequency Assessment Tool, compares favorably (r = 0.78; P <.01) with the Oregon Health Sciences University Diet Habit Survey. The purpose of this study was to assess the validity and reliability of the HFD in estimating fat intake as a percentage of calories. METHODS: The validity study assessed 137 patients undergoing cardiac rehabilitation (age, 60.7 +/- 11.3 years) who completed the HFD (29 questions, 11 of which were dietary fat related [fat subscore]) and a 3-day food record. A regression equation was obtained using HFD subscores to estimate fat intake as a percentage of calories. The regression equation was tested using 50 patients not included in the original cohort. Reliability was assessed using a third group of 31 patients in a 4-week test-retest analysis. RESULTS: The correlation coefficient between the 3-day record and the HFD fat subscore was 0.65 (P <.01). The correlation coefficient for women (r = 0.77) was slightly higher than for men (r = 0.62). The regression equation derived from the HFD fat subscore was as follows: percentage of dietary fat = 50.65 - 0.736 (HFD fat subscore). The correlation coefficient for actual and predicted values was 0.58 (P <.01). Differences between estimated fat intake, as determined by the 3-day record and the HFD, ranged from 0% to 25% and were within 5% for 26 of the 50 subjects (52%), and within 10% for 41 of the 50 subjects (82%). The mean difference between the two measures was 1.5% (P =.17). Test-retest reliability was high for both the HFD total score (r = 0.95) and the HFD fat subscore (r = 0.85; P <.01). CONCLUSIONS: The HFD is an inexpensive, valid, and reliable clinical instrument for assessing dietary fat. It can be a viable alternative to other time-consuming methods, including computerized analysis.

Aged↗
PubMedDate not supplied

Lipids, lipoproteins, and exercise.

PURPOSE: Dose-response relationships between exercise training volume and blood lipid changes suggest that exercise can favorably alter blood lipids at low training volumes, although the effects may not be observable until certain exercise thresholds are met. METHODS AND RESULTS: Plasma triglyceride reductions are often observed after exercise training regimens requiring energy expenditures similar to those characterized to increase high-density lipoprotein cholesterol (HDL-C). Thresholds established from cross-sectional and longitudinal exercise training studies indicate that 15 to 20 miles/week of brisk walking or jogging, which elicit between 1,200 to 2,200 kcals of energy expenditure per week, is associated with triglyceride reductions of 5 to 38 mg/dL and HDL-C increases of 2 to 8 mg/dL. Exercise training seldom alters total cholesterol and low-density lipoprotein cholesterol (LDL-C) unless dietary fat intake is reduced and body weight loss is associated with the exercise training program, or both. Thus, for most individuals, the positive effects of regular exercise are exerted on blood lipids at low training volumes and accrue so that noticeable differences frequently occur with energy expenditures of 1,200 to 2,200 kcals/week. CONCLUSIONS: It appears that weekly exercise caloric expenditures that meet or exceed the higher end of this range are more likely to produce the desired lipid changes. Regarding hyperlipidemic disorders, the primary means for intervention is pharmacologic, whereas diet modification, weight loss, and exercise, although important, are viewed as adjunctive therapies. Because much is known about the exercise training-induced plasma lipid and lipoprotein modifications as well as the mechanisms responsible for these changes, rehabilitation professionals can better develop a comprehensive medical management plan that optimizes pharmacologic, reduced dietary fat intake, weight loss, and exercise interventions.

Apolipoproteins↗