Factors associated with perceived exertion and estimated time limit at lactate threshold

The purpose was to identify the most predictive parameters for perceived exertion and estimated time limit responses at the velocity corresponding to the lactate concentration threshold. The former scale concerns the subject's current status (how hard he feels the exercise currently is) whereas the latter scale deals with a subjective prediction of how long the current exercise level can be maintained. Multiple regression equations were developed among physiological, psychological, nutritional, and individual parameters (subjects' characteristics and performances) as independent variables, and perceived exertion or estimated time limit as dependent variables. Independent variables were collected before or during an incremental running field test. 94 regional to national level athletes (47 endurance-trained runners, 11 sprinters, and 36 handball players) participated. Multiple stepwise regression showed that Rating of Perceived Exertion and Estimated Time Limit at the lactate threshold were mainly mediated by factors relative to the performance expressed in percentage of the maximal aerobic velocity. Secondary factors which contribute significantly as perceptual predictors were related to various classes of factors except for psychological factors.     

Stress and blood glucose in type II diabetes mellitus

Six adults with non-insulin dependent diabetes mellitus participated in a laboratory procedure to determine the effects of an acute Stressor, mental arithmetic, on blood glucose, cardiovascular, and subjective indices of stress. They then completed 12 days home monitoring of stressful events, subjective stress, and blood glucose. Diet and activity were controlled to evaluate the direct effects of stress on blood glucose in the natural environment. Laboratory results showed significant increases in blood glucose, cardiovascular (HR and SBP), and subjective stress ratings during the mental arithmetic task when compared to a resting condition. Home monitoring data were consistent with the laboratory findings; blood glucose range tended to be greater on high vs low stress days, especially when the difference between high and low stress was greatest. These findings suggest that the laboratory stress induction procedure was externally valid and that in the natural environment, stress has a hyperglycemic effect on blood glucose.     

Validity and reliability of a Cantonese-translated rating of perceived exertion scale among Hong Kong adults

This study assessed the validity and reliability of the Cantonese-translated version of the Borg 6-20 Rating of Perceived Exertion (RPE) scale during continuous incremental cycle ergometry by Hong Kong adults. A total of 54 participants (25 males and 29 females), ages 22.2 +/- 4.7 yr., volunteered to participate. They performed two trials of identical continuous incremental cycling exercise 1 wk. apart for the reliability test. The objective measures of exercise intensity (heart rate, power output, and oxygen consumption) and the subjective measure of effort (RPE) were obtained during the incremental exercise. Significant (p < .01) Pearson correlations were found when RPE values were correlated with heart rate (rs > or = .73), power output (rs > or = .69), and oxygen consumption (rs > or = .68). The overall test-retest intraclass correlation (R = .92) indicated that the scale was reliable. In conclusion, this Cantonese scale for rating of perceived exertion appears to be a valid and reliable psychophysiological tool to measure perceptions of exertion during controlled cycle ergometer exercise by Hong Kong adults.     

Effect of pedal rate and power output on rating of perceived exertion during cycle ergometry exercise

This study examined differentiated rating of perceived exertion (RPE), heart rate, and heart-rate variability during light cycle ergometry exercise at two different pedal rates. 30 healthy men (22.6 +/- 0.9 yr.) were recruited from a student population and completed a continuous 20-min. cycle ergometry exercise protocol, consisting of a 4-min. warm-up (60 rev./min., 30 Watts), followed by four bouts of 4 min. at different combinations of pedal rate (40 or 80 rev./min.) and power output (40 or 80 Watts). The order of the four combinations was counterbalanced across participants. Heart rate was measured using a polar heart-rate monitor, and parasympathetic balance was assessed through time series analysis of heart-rate variability. Measures were compared using a 2 (pedal rate) x 2 (power output) repeated-measures analysis of variance. RPE was significantly greater (p<.05) at 80 versus 40 rev./min. at 40 W. For both power outputs heart rate was significantly increased, and the high frequency component of heart-rate variability was significantly reduced at 80 compared with 40 rev./min. These findings indicate the RPE was greater at higher than at lower pedalling rates for a light absolute power output which contrasts with previous findings based on use of higher power output. Also, pedal rate had a significant effect on heart rate and heart-rate variability at constant power output.     

Accuracy in discriminating blood glucose levels in a sample of children with type 1 diabetes

The present study explores accuracy in estimating blood glucose levels (BGL) in children with type 1 diabetes and analyzes the kinds of symptoms and cues which they use to estimate their BGL. Forty two children with type 1 diabetes completed a SI/IC-3 scale consisting of 28 items (22 symptoms and 6 feelings), indicating those which they perceived at the time and their intensity. They estimated their BGL and gave reasons for their estimation, before having a blood glucose level analysis performed. The results indicated great variability in the accuracy of estimating BGL. They showed failures in the correct discrimination of symptoms of hypoglycemia as well as the presence of false beliefs regarding indicative symptoms of hyperglycemia, and the absence of symptoms as an indicator for euglycemia, beliefs which provoke different and frequent errors in the estimation of BGL. Correct use of external signs is shown to be related to correct estimations of normal BGL, as well as hypoglycemia and hyperglycemia. We discuss the implications these results could have on designing psychological intervention procedures for diabetics in the form of training programs to discriminate BGL accurately, taking into account these findings and previous studies completed in the same field.     

Associations of blood glucose control with self-efficacy and rated anxiety/depression in type II diabetes mellitus patients

We investigated the possible relations of hemoglobin A1c (HbA1c) level, a parameter of blood glucose control with scores on anxiety, depression, and self-efficacy for 113 outpatients (55 men and 58 women) with type II diabetes mellitus. The relation between the HbA1c level and the self-efficacy scores as well as with the ratings of anxiety and depression was evaluated. A significant relation was found for the HbA1c level with the scores; however, self-efficacy and anxiety and depression showed no association. These results suggest that HbA1c can be maintained at better levels by increasing self-efficacy of diabetic patients.     

Differentiated ratings of perceived exertion and physiological responses during aerobic dance steps by impact/type of arm movement

Overall ratings of perceived exertion, i.e., undifferentiated RPE, are often used as indicators of exercise intensity during walking, jogging, and cycling; however, conflicting results concerning RPE during aerobic dance exercise have been reported, and the use of differentiated RPE, i.e., local RPE and central RPE, has not been investigated. The purposes of this study were to assess local, central, and over-all RPE, and physiological responses [heart rate (HR); % HRmax; absolute and relative VO2;% VO2 max, ventilation (VE), ventilatory equivalent (VE.VO2(-1); and oxygen pulse] during aerobic dance exercise varied by Arm Movement (Static Arm vs Dynamic Arm) and Impact (High vs Low). Trained women (N = 25; max VO2 = 50.4 +/- 7.5 ml.kg-1.min.-1) completed four aerobic dance steps. No RPE were significantly correlated with heart rate or VO2; however, for all steps all RPE were significantly (r = .40-.62) correlated with VE.VO2(-1) or VE. No interactions were present for RPE or physiological variables, and main effects were noted for Impact and Arm Movement. All RPE were greater for High Impact and for Static Arm Movement. Because VE and VE.VO2(-1) were correlated with Overall RPE for all steps, this may suggest that participants "attended to" perceived changes in respiratory phenomena during aerobic dance exercise. It appears that during combined arm-and-leg aerobic dance exercise the use of Overall RPE is sufficient to assess perceptual sensations associated with the intensity of the exercise. Changes in Overall RPE were proportionate to objective measures of exercise intensity, i.e., HR and VO2; however, it is recommended that both HR and Overall RPE be used to assess fully a participant's objective and subjective responses during aerobic dance exercise.     

Mood changes associated with blood glucose fluctuations in insulin-dependent diabetes mellitus

Individuals with insulin-dependent diabetes mellitus (IDDM) and their healthcare practitioners believe that extreme blood glucose (BG) fluctuations are characterized by changes in subjective mood states and emotional behavior, as well as physical symptoms. This study examined relationships between BG levels and self-reported mood in a group of 34 IDDM adults. The method followed a within-subject, repeated-measures design employed in previous studies of physical symptoms associated with diabetic glucose. Four times each day, participants completed a mood/symptom checklist just prior to a self-measurement of BG until 40 checklists had been completed. Half the items on the checklist described physical symptoms and half described mood states. In addition, half the mood items described negative states and half described positive states. Within-subject correlations and regressions showed that moods were related to BG for the majority of participants and that, like physical symptoms, mood-BG relationships were highly idiosyncratic. Low BG levels tended to be associated with negative mood states, primarily self-reported "nervousness." Positive mood items were almost always associated with high BG. High BG levels also frequently correlated with negative mood states, although the negative mood items that tended to relate to high glucose (anger, sadness) differed from those that tended to relate to low BG. The implications of these findings for self-treatment and glucose perception in the IDDM individual are discussed.     

Relationship between ratings of perceived exertion and exercise-induced decrease in state anxiety

24 females (aged 18 to 28 yr.) completed two 24-min., randomly ordered bicycle ergometer exercise bouts at workloads maintaining steady state at 30% and 60% heart-rate reserve. Ratings of perceived exertion (RPE) were recorded at 3-min. intervals from Minutes 9 to 24 of exercise. State anxiety was measured prior to, immediately following and 50 min, after cessation of exercise. Regression analysis indicated no relationship between RPE and the pre- to postexercise changes in state anxiety.     

Environmental stress and blood glucose change in insulin-dependent diabetes mellitus

Blood glucose (BG) response to psychological stress in insulin-dependent diabetes mellitus (IDDM) patients has not been firmly established. We report a study designed to address the gaps and methodological difficulties reviewed. Subjects with IDDM were exposed to two sessions (12 weeks apart) of two 20-min standardized stressors (active and passive) and a control condition administered in counterbalanced order. To measure BG response, subjects were connected to a glucose/insulin infusion system providing continuous BG measurement. Mood checklist measures were obtained at prestressor, poststressor, and recovery periods. During the first session of testing, the active stressor was associated with significantly more absolute change in BG response than the passive stressor. Results also indicate that IDDM subjects' BG response to this active stressor was idiosyncratic but significantly reliable over time.     

Medication adherence and diabetes control in urban African Americans with type 2 diabetes.

In 181 urban African Americans with Type 2 diabetes, medication adherence was assessed using a measure designed specifically for an urban, impoverished sociodemographic population. Hemoglobin A-sub(1c), blood pressure and cholesterol levels, medication-related beliefs, and depression were assessed. Seventy-four percent of the sample reported adherence to diabetes medication. Adherence, adjusted for age, was associated with lower hemoglobin A-sub(1c). The specific behaviors associated with poorer diabetes control were forgetting to take medications and running out of medications. Knowledge of blood glucose goals differed for adherers and nonadherers. Blood pressure and cholesterol medication adherence rates were not associated with actual levels of blood pressure or lipids, respectively. These data suggest that specific medication-taking behaviors are important to diabetes control and constitute logical targets for interventions. ((c) 2005 APA, all rights reserved).     

Effects of a checklist on self-assessment of blood glucose level by a memory-impaired woman with diabetes mellitus

This study evaluated effects of a checklist on the accuracy of self-assessment of blood glucose level by a diabetic woman with memory impairments caused by viral encephalitis. The checklist consisted of 54 steps for operating an electronic glucometer, which the subject performed in sequence and checked off when completed. Following introduction of the checklist, the percentage of steps completed correctly increased in simulated and actual blood glucose tests and yielded clinically useful information.     

Accuracy of blood glucose estimation by children with diabetes: an investigation of repeated practice with growth curve modeling

This study used growth curve modeling to explore whether practicing the task of estimating blood glucose levels would increase accuracy in children with type 1 diabetes. It was predicted that accuracy would improve with practice and that younger, anxious, poorly adjusted children would improve most. 43 attendees at a diabetes summer camp participated. Their mean age was 13.4 yr. (SD = 1.6). All were Euro-American, and 22 were girls. Change in accuracy was best represented by a quadratic function, and this model fit the data well. Overall, participants' accuracy improved initially and then deteriorated. Results indicate that older children were more likely to improve and then deteriorate. Younger children were more likely to improve and sustain those improvements. Results indicate that practicing the task of estimating is not an effective way to increase accuracy and may be contra-indicated. These results can help guide research and clinical use of glucose estimation in children.     

Psychological stress and blood glucose regulation in type I diabetic patients

Fifteen Type I diabetic patients self-monitored daily mean blood glucose levels (BGL), psychological stress, diet, exercise, and insulin injections for a period of 8 weeks. Separate multiple-regression analyses were conducted for each subject to assess the predictability of BGL from stress reports, independent of the effects of diet, exercise, and insulin self-administration. Considerable individual variability in findings was evident, with stress predicting BGL in a statistically significant manner in 7 of the 15 subjects. Stress had a significant effect on BGL independent of diet, exercise, and insulin administration for each of these 7 subjects. Discussion focused on the problems of measuring the key self-management behaviors influencing BGL and on the possibility that a subgroup of diabetic patients may be BGL stress responders.     

Eating behaviors and emotional distress are predicted by treatment and adverse outcome in patients with type 2 diabetes

Depression and anxiety are hightly prevalent among patients with Type 2 Diabetes (T2D), however not commonly related to outcomes, treatment and comorbidities. Eating behaviors could also have an implication. To evaluate the relation between mood and eating behaviors with demographic, physical, treatment, biochemical profiles and chronic comorbidities in T2D we conducted this exploratory cross sectional study in a population from Mexico. Hospital Anxiety and Depression Scale and the Three Factor Eating Questionnaire Revised 21 (TFEQ-R21) were correlated with age, gender, blood pressure, treatment and comorbidities (nephropathy, neuropathy, retinopathy and cardiopathy). Multi-linear regression models and 2^k factorial analyses were conducted. Sixty-one patients (31 male) 55 years old (SD 13) with at least 5 years of T2D were included. Anxiety correlated with depression (r = 0.25, p < 0.05). Gender (women) (std B 0.026, p < 0.001), insulin therapy (std B 0.3, p = 0.11), systolic blood pressure (std B 0.263, p = 0.02) and cardiovascular disease (std B 0.232, p = 0.035) predicted depression. Insulin therapy had a positive effect in cognitive restraint. (std B 0.32, p = 0.001). Age (std B 0.37, p = 0.003) and systolic blood pressure (std B 0.237, p = 0.048) predicted positively emotional eating (not previously published). 2^k factorial analyses proved additive interaction between complications and insulin therapy with depression. This study supports the relation between mood disorders and eating behaviors with demographic, physical, treatment, biochemical profiles and chronic comorbidities in T2D and the additive interaction between factors and mood disorders.     

Behavioral assessment of eating patterns and blood glucose in diabetes using the Self-Monitoring Analysis System

The Self-Monitoring Analysis System is a set of microcomputer programs that were developed to remove clinical judgment from the task of behavioral assessment using self-monitoring diaries. The program is written in Turbo Pascal and runs on MS-DOS (16-bit) or CP/M (8-bit) microcomputer systems. The program allows the user to custom design data bases with hundreds of binary, categorical, integral, and real variables. Full-screen data-entry forms can be custom designed, and random access files allow for flexible data entry and editing. The program makes extensive utilization of Pascal’s very flexible data structure capabilities. Dynamic allocation of memory allows the program to maximize its use of available RAM. Data from a patient with diabetes is presented as a case study illustrating the system’s utility.     

Infant attractiveness and perceived temperament in the prediction of attachment classifications

The influence of infant physical attractiveness and infant temperament on the mother-infant relationship at 12 months of age was examined. Physical attractiveness of the infant was rated by 48 adults, and infant temperament was assessed by use of the Toddler Temperament Scale, which yields indices of activity level, rhythmicity, approach, adaptability, intensity, mood, persistence, distractibility, and threshold. Mother-infant attachment was measured via the Strange Situation. Results showed that 46% of the variance in attachment classification was accounted for by five of the nine dimensions of temperament (withdrawal from new situations, high intensity of response, low distractibility, negative mood, and low threshold of response). Physical attractiveness and other dimensions of temperament did not add significant amounts of variance over and above that contributed by the first five dimensions to the prediction of attachment.     

Predicting performance in ski and swim championships: effectiveness of mood, perceived exertion, and dispositional optimism

Two studies were performed with young athletes to investigate the utility of three psychological tests regarding the prediction of sport performance: the Profile of Mood States. Ratings of Perceived Exertion, and Dispositional Optimism. In Study 1, young male and female cross-country skiers and ski-marksmen in final preparation for the Junior National Swedish Championships were tested. Measured 5 wk. before both competitions, the higher the optimism (LOT), the better performance. In Study 2, which tested young swimmers in preparation for the Senior National Swedish Championships, competitors who had the highest scores on optimism performed less well during the competitions. The results are interpreted to indicate that optimism presents an important factor for predicting achievement in sports.     

Diabetes distress,illness perceptions and glycaemic control in adults with type 2 diabetes

The emotional distress associated with adjusting to and living with diabetes has been termed diabetes distress. Diabetes distress is associated with glycaemic control but interventions to reduce diabetes distress have failed to consistently improve diabetes control. Various illness perceptions have previously been linked with both diabetes distress and glycaemic control but interrelationships between these features have not been previously investigated. We hypothesised that illness perceptions mediate the relationship between diabetes distress and glycaemia. Participants with type 2 diabetes attending diabetes outpatient clinics (n = 84) provided demographic and clinical information and completed the Diabetes Distress Scale-17 and the Brief Illness Perceptions Questionnaire. Using regression analysis we demonstrated that the illness perceptions of personal control, regimen-related distress, socioeconomic status and insulin use were significant contributors in the final model predicting HbA_1c. Higher levels of personal control were associated with better glycaemic control. Conversely, regimen-related distress was associated with hyperglycaemia. Mediation analyses showed that the relationship between regimen-related distress and HbA_1c was mediated by personal control. Our work suggests that psychological interventions designed to reduce diabetes distress may be more efficacious in improving glycaemic control if they address an individual’s perception of personal control.