PubMed HealthSearch

Biomedical subjects

R F DeBusk

Publications and source records attributed to R F DeBusk.

At least 19 recordsLinked to original sources

Group- vs home-based exercise training in healthy older men and women. A community-based clinical trial.

OBJECTIVE: --To determine the effectiveness of group- vs home-based exercise training of higher and lower intensities among healthy, sedentary older adults. DESIGN: --Year-long randomized, controlled trial comparing (1) higher-intensity group-based exercise training; (2) higher-intensity home-based exercise training; (3) lower-intensity home-based exercise training; or (4) assessment-only control. SETTING: --General community located in northern California. PARTICIPANTS: --One hundred sixty women and 197 men 50 to 65 years of age who were sedentary and free of cardiovascular disease. One out of nine persons contacted through a community random-digit-dial telephone survey and citywide promotion were randomized. INTERVENTIONS: --For higher-intensity exercise training, three 40-minute endurance training sessions per week were prescribed at 73% to 88% of peak treadmill heart rate. For lower-intensity exercise training, five 30-minute endurance training sessions per week were prescribed at 60% to 73% of peak treadmill heart rate. MAIN OUTCOME MEASURES: --Treadmill exercise test performance, exercise participation rates, and heart disease risk factors. RESULTS: --Compared with controls, subjects in all three exercise training conditions showed significant improvements in treadmill exercise test performance at 6 and 12 months (P less than .03). Lower-intensity exercise training achieved changes comparable with those of higher-intensity exercise training. Twelve-month exercise adherence rates were better for the two home-based exercise training conditions relative to the group-based exercise training condition (P less than .0005). There were no significant training-induced changes in lipid levels, weight, or blood pressure. CONCLUSIONS: --We conclude that (1) this community-based exercise training program improved fitness but not heart disease risk factors among sedentary, healthy older adults; (2) home-based exercise was as effective as group exercise in producing these changes; (3) lower-intensity exercise training was as effective as higher-intensity exercise training in the home setting; and (4) the exercise programs were relatively safe.

Aged

Smoking cessation after acute myocardial infarction: effects of a nurse-managed intervention.

STUDY OBJECTIVE: To determine the effect of a nurse-managed intervention for smoking cessation in patients who have had a myocardial infarction. DESIGN: Randomized, with a 6-month treatment period and a 6-month follow-up. SETTING: Kaiser Foundation hospitals in Redwood City, Santa Clara, Hayward, and San Jose, California. PATIENTS: Sequential sample of 173 patients, 70 years of age or younger, who were smoking before hospitalization for acute myocardial infarction. Eighty-six patients were randomly assigned to the intervention and 87 to usual care; 130 patients (75%) completed the study and were available for follow-up. INTERVENTION: Nurse-managed and focused on preventing relapse to smoking, the intervention was initiated in the hospital and maintained thereafter primarily through telephone contact. Patients were given an 18-page manual that emphasized how to identify and cope with high-risk situations for smoking relapse. MEASUREMENTS AND MAIN RESULTS: One year after myocardial infarction, the smoking cessation rate, verified biochemically, was 71% in the intervention group compared with 45% in the usual care group, a 26% difference (95% CI, 9.5% to 42.6%). Assuming that all surviving patients lost to follow-up were smoking, the 12-month smoking cessation rate was 61% in the intervention group compared with 32% in the usual care group, a 29% difference (95% CI, 14.5% to 43.5%). Patients who either resumed smoking within 3 weeks after infarction or expressed little intention of stopping in the hospital were unlikely to have stopped by 12 months. CONCLUSIONS: A nurse-managed smoking cessation intervention largely conducted by telephone, initiated in the hospital, and focused on relapse prevention can significantly reduce smoking rates at 12 months in patients who have had a myocardial infarction.

Adult

Training effects of long versus short bouts of exercise in healthy subjects.

To evaluate the "threshold" duration of exercise required to produce training effects, 18 healthy men aged 51 +/- 6 years completing 30 minutes of exercise training/day were compared with 18 men aged 52 +/- 6 years completing three 10-minute bouts of exercise/day, each separated by at least 4 hours. Exercise training intensity was moderate (65 to 75% of peak treadmill heart rate). During the 8-week study period VO2 max increased significantly in both groups from 33.3 +/- 3.2 to 37.9 +/- 3.5 ml/kg/min in men performing long exercise bouts and from 32.1 +/- 4.6 to 34.5 +/- 4.5 ml/kg/min in men performing short exercise bouts (p less than 0.05 within and between groups). Adherence to unsupervised exercise training performed at home and at work by men in long and short bouts was high; total duration of training completed was 96 and 93% of the prescribed amount and total number of sessions completed was 92 and 93% of that prescribed, respectively. In both groups exercise heart rate measured by a portable microprocessor was within or above the prescribed range for greater than 85% of the prescribed duration. Thus, multiple short bouts of moderate-intensity exercise training significantly increase peak oxygen uptake. For many individuals short bouts of exercise training may fit better into a busy schedule than a single long bout.

Electrocardiography

Identifying strategies for increasing employee physical activity levels: findings from the Stanford/Lockheed Exercise Survey.

While worksite exercise programs offer a number of potential advantages with respect to increasing physical activity levels in American adults, typical participation rates remain relatively low. The purpose of this study was to explore employee preferences and needs related to physical activity programming in a major work setting in northern California. Two-thirds (399) of a randomly selected sample of employees responded to a mailed survey. Male and female employees reporting no regular aerobic activity over the past two years more strongly endorsed a number of erroneous beliefs concerning exercise, reported less support for engaging in exercise both at home and at work, and avoided even routine types of activity to a greater extent than more active individuals (p values less than 0.001). Current exercisers reported use of a greater number and variety of motivational strategies as part of their exercise program than past exercisers who were not currently active (p less than 0.001). Respondents, regardless of exercise status and age, reported preferences for moderate-intensity activity occurring away from the workplace which could be performed on one's own rather than in a group or class. Implications of the findings with respect to development of educational and behavioral programs for the current employee population are discussed.

Adolescent

Cost-benefit analysis of early return to work after uncomplicated acute myocardial infarction.

The economic consequences of an Occupational Work Evaluation designed to identify low risk patients recovering from uncomplicated acute myocardial infarction (AMI) and hasten their return to work was evaluated in a randomized trial. Two hundred one employed, clinically low risk men recovering from AMI were randomized to undergo an intervention (intervention group, 99 patients) consisting of an Occupational Work Evaluation or to receive usual care (usual care group, 102 patients). The time to return to work was reduced from 75 days in usual care patients to 51 days in intervention patients (p less than 0.002). Significant differences were found between groups for medical costs and occupational income during follow-up. Total medical costs per patient were lower in the intervention patients than in the usual care patients in the 6 months after AMI ($2,970 vs $3,472). Occupational income per patient was higher in intervention patients than in the usual care group in the 6 months after AMI ($9,655 vs $7,553). The per capita benefit accounting for medical costs and occupational income was $6,685 for intervention patients and $4,081 for usual care patients. Projected to the greater than 300,000 low risk, employed survivors of AMI annually in this country, the savings generated by the Occupational Work Evaluation could yield an annual economic benefit greater than 800 million dollars.

Algorithms

Specialized testing after recent acute myocardial infarction.

A wide variety of specialized laboratory tests have been used to characterize prognosis and functional capacity soon after a patient has an acute myocardial infarction. Few attempts have been made to integrate the available data on these tests into clinically relevant guidelines for the clinician. This review evaluates the use of these tests, alone and in combination, throughout the course of recovery from acute myocardial infarction. The primary objective of these tests is to quantify myocardial ischemia and left ventricular dysfunction, the pathophysiologic basis of prognosis and functional capacity. The selection of one test over another depends on whether either test provides information on myocardial ischemia and left ventricular dysfunction not available through the standard clinical evaluation, and the risk, quality, and cost associated with each test. The stepwise application of specialized testing after acute myocardial infarction enables the identification of three groups of patients: approximately 20% at very high risk, due primarily to irreversible left ventricular dysfunction; approximately 30% at moderately high risk, due primarily to myocardial ischemia; and approximately 50% at low risk who are free of significant left ventricular dysfunction or myocardial ischemia. Accurate discrimination among these three groups enables the application of aggressive medical and surgical therapy to patients at moderate to high risk and accelerated recovery for patients at low risk. Specialized testing also helps to guide subsequent management after thrombolysis and revascularization procedures.

Coronary Angiography

Influence of regular aerobic exercise on psychological health: a randomized, controlled trial of healthy middle-aged adults.

Although a variety of psychological benefits have been attributed to regular exercise, few experimentally controlled studies of healthy individuals currently exist. One hundred twenty healthy, sedentary, middle-aged men and women were randomly assigned to either a 6-month home-based aerobic exercise training program or to an assessment-only control condition. Adherence across the 6-month period was found by both self-report and heart rate microprocessor methods to exceed 75% in both sexes. To assess changes in a variety of psychological variables over time, a 14-item Likert rating scale was completed and returned on a biweekly basis throughout the 6-month period. Slope analyses conducted on the 11 items attaining acceptable test-retest reliability coefficients showed significant between-groups differences on the 3 items most closely associated with the actual physical changes that occurred with exercise (all ps less than .004). Implications in relation to repeated measurement of psychological changes in nonclinical populations and the determination of the relevant population-, activity-, and program-specific parameters involved are discussed.

Adaptation, Psychological

Early return to work after uncomplicated myocardial infarction. Results of a randomized trial.

To determine if an occupational work evaluation could shorten the time to return to work, 201 employed men aged 49 +/- 7 years who were recovering from uncomplicated myocardial infarction were randomized to usual care (n = 102) or to an occupational work evaluation (n = 99). The occupational work evaluation consisted of a symptom-limited treadmill test performed 23 +/- 3 days after myocardial infarction and a formal recommendation to the patient and primary physician that the patient return to work within the next two weeks. The groups did not differ in age, medical status, comorbid disease, occupation type, or years on the job. At six months, 92% of patients receiving the intervention and 88% of patients receiving usual care were working either full- or part-time. Return to full-time work occurred at a median of 51 days in patients receiving the intervention and 75 days in patients receiving usual care. This 32% reduction in the convalescence period was associated with +2102 of additional earned salary per intervention patient in the six months after myocardial infarction. One or more recurrent cardiac events occurred in 14 intervention patients (one death, one nonfatal myocardial infarction, three angioplasties, and nine coronary surgeries) and in 13 usual-care patients (two deaths, three nonfatal myocardial infarctions, six angioplasties, and seven coronary surgeries) in the six months after myocardial infarction. The early return to work of low-risk patients based on an occupational work evaluation is associated with important economic benefits.

Attitude to Health

Effectiveness of self-monitored, home-based, moderate-intensity exercise training in middle-aged men and women.

The effects of 6 months of self-monitored, home-based exercise training on maximal oxygen uptake (VO2 max), body composition and plasma lipid levels of healthy, sedentary, middle-aged persons were evaluated in 60 men, aged 49 +/- 6 years, and 60 women, aged 47 +/- 5 years. Moderate-intensity training was performed 5 times per week in sessions of 47 +/- 7 minutes and 54 +/- 8 minutes for men and women, respectively. The individually prescribed range of heart rate corresponded to 65 to 77% of the peak value during symptom-limited treadmill testing (mean of 72% for men and 69% for women). Caloric expenditure per training session was approximately 345 kcal for men and 235 kcal for women. VO2 max increased 15% in men and 9% in women (both p less than 0.01). The greater increase in VO2 max in men than in women primarily reflected greater adherence to training in men (greater than or equal to 90% vs greater than or equal to 75%). The increase in VO2 max in women who showed very high adherence was comparable to that of men. Body weight decreased, by 1.5 +/- 10 kg, in men (p less than 0.05) but not in women undergoing training. No significant training-induced changes in plasma lipid levels were noted in either men or women. Baseline orientation and follow-up telephone calls required less than 1 hour of staff time per participant. Self-monitored, moderate-intensity, home-based exercise training significantly increases functional capacity in healthy, middle-aged men and women. Such training provides an alternative to group-based exercise training.

Adult

Assessment by a microprocessor of adherence to home-based moderate-intensity exercise training in healthy, sedentary middle-aged men and women.

Research in exercise training of healthy persons, which has been conducted almost exclusively in supervised group programs, is relatively expensive for the investigator and inconvenient for the participant. To overcome these obstacles, self-monitored moderate-intensity home-based exercise training was prescribed for 28 middle-aged men and 26 middle-aged women. The median energy expenditure prescribed for each of 5 weekly exercise sessions was 4 cal/kg body weight, or 317 kcal for men and 265 kcal for women, corresponding to a median duration of 45 and 60 minutes, respectively. In the next 24 weeks, peak oxygen uptake increased 13.7% in men who exercised, from 31 +/- 4 to 37 +/- 4 ml/kg/min, and 10% in women who exercised, from 26 +/- 4 to 29 +/- 5 ml/kg/min (p less than 0.001 for both comparisons). The proportion of prescribed caloric expenditure per session, which was documented by a solid-state heart rate recorder, was 108% in men and 90% in women. The duration of training at heart rates above the prescribed range approximated 10 minutes per session for both men and women; the proportion of total caloric expenditure represented by exercise at heart rates exceeding the prescribed limit was 9% for men and 4% for women. The proportion of time spent within the prescribed heart rate range during training sessions was 76% for men and 84% for women. Training-induced musculoskeletal problems were reported by 6 men and no women. No subject sought medical attention and all resumed training within 1 week.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

Assessment of prescribed increases in physical activity: application of a new method for microprocessor analysis of heart rate.

A portable solid-state recorder-display system was used to measure and analyze heart rate during the waking hours of 3 consecutive days in free-living sedentary normal middle-aged men who were randomized to undergo 3 regimens of physical activity during a 12-week period: low-intensity exercise training at home (n = 21), high-intensity exercise training at home (n = 23) and customary activity (n = 20). This was done to determine whether the system could detect changes in heart rate and, indirectly, in physical activity within the 3 groups. In both training groups the percentage of total recorded time spent within the prescribed high or low heart rate range recorded at 6 or 12 weeks increased significantly (p less than 0.05), whereas control subjects showed no increase above baseline values. Peak oxygen consumption increased by 8% and 17% in men undergoing low- and high-intensity training, whereas in control subjects it did not change. This solid-state system reliably measures prescribed increases in heart rate and provides an indirect measure of physical activity in normal sedentary men undergoing exercise training at home.

Ambulatory Care

Effects of low- and high-intensity home-based exercise training on functional capacity in healthy middle-aged men.

The effects of 12 weeks of home-based exercise training on peak oxygen consumption (VO2 max) in healthy sedentary middle-aged men, mean age 49 +/- 6 years, were evaluated. Twenty-one men trained at low intensity, 23 trained at high intensity and 20 were control subjects. Individually prescribed low- and high-intensity training was performed 5 times per week within a range of 42 to 60% and 63 to 81% of baseline VO2 max, corresponding to average heart rates of 102 to 122 and 128 to 148 beats/min, respectively. Caloric expenditure per training session approximated 350 kcal in both groups; adherence was at least 90% in both groups. VO2 max increased 8% in patients who trained at low intensity, 17% in those who trained at high intensity (both p less than 0.001), and not at all in control subjects. Low-intensity exercise training at home significantly augments functional capacity in healthy sedentary middle-aged men.

Adult

The effects of exercise training programs on psychosocial improvement in uncomplicated postmyocardial infarction patients.

To determine the effects of exercise training programs on psychosocial improvement in uncomplicated postmyocardial infarction patients, 210 male patients hospitalized for an acute myocardial infarction (MI) were randomized to three week symptom limited treadmill (TM) plus home exercise training, TM plus medically supervised gym training, TM without formal exercise program or control, where patients were seen only at six months post MI. Patients in this sample were at low risk for psychosocial disturbance (13% were moderate to severely depressed, 23% reported marital disturbance and 3% were extremely anxious). Patients in the training groups improved from 3 to 26 weeks post MI on all depression and anxiety measures. The gym training group showed a significant reduction on one depression measure compared to no training and on one anxiety measure compared to controls.

Adaptation, Psychological

Exercise testing to enhance wives' confidence in their husbands' cardiac capability soon after clinically uncomplicated acute myocardial infarction.

The effects of wives' involvement in their husbands' performance of treadmill exercise testing 3 weeks after clinically uncomplicated acute myocardial infarction was compared in 10 wives who did not observe the test, 10 who observed the test, and 10 who observed and participated in the test themselves. In a counseling session after the treadmill test, couples were fully informed about the patient's capacity to perform various physical activities. Wives' final ratings of confidence (perceived efficacy) in their husbands' physical and cardiac capability were significantly (p less than 0.05) higher in those who also performed the test than in the other 2 groups. Only wives who walked on the treadmill increased their ratings of their husbands' physical and cardiac efficacy to a level equivalent to those of their husbands. Spouses' and patients' perceptions of patients' cardiac capability after treadmill testing and counseling at 3 weeks were significantly correlated with peak treadmill heart rate and workload at 11 and 26 weeks. Efficacy ratings at 3 weeks were slightly better than peak 3-week treadmill heart rate and workload as predictors of treadmill performance at 11 and 26 weeks. Participation in treadmill testing early after acute myocardial infarction is an effective means for reassuring spouses about the capacity of their partners to resume their customary physical activities with safety.

Adult