Extent of motor unit activation in the quadriceps muscles of healthy subjects.
Explore the source record for details and available documents.
Adult↗
Biomedical subjects
E Suter
Publications and source records attributed to E Suter.
Ultrastructural modification of human skeletal muscle tissue with 6-month moderate-intensity exercise training.
The study was aimed at investigating if endurance training of moderate intensity and longer duration, intended to promote health rather than performance, evokes ultrastructural changes in skeletal muscle tissue comparable to those observed after high-intensity protocols. Twenty healthy, middle-aged men enrolled in a 6-month, home-based jogging program of 120 min/wk at 75% VO2max. Only 12 men showed a sufficient exercise adherence over the 6 months (> or = 60 min/wk on average) and were included into statistical analysis. Their average training activity was 105 +/- 31 min/wk. The results revealed significant increases in VO2max (+8.4%, p < 0.01) and submaximal power output (+18.1%, p < 0.01). Total mitochondrial volume density in M. vastus lateralis increased by 20% (p < 0.05) with a larger increase in subsarcolemmal volume compared to central volume (50% vs 15%). No changes in volume of intracellular lipid droplets, capillary density, capillary per fiber ratio, fiber mean cross-sectional area and muscle fiber type could be observed. Body composition analysis showed a decrease in trunk fat mass (-7.3%, p < 0.05) and an increase in trunk lean mass (+1.7%, p < 0.05), while changes in the legs were not significant. It can be concluded that a moderate-intensity, health oriented endurance training beneficially affected cardiovascular and muscle oxidation capacity as well as body composition in the trunk area. No adaptations in capillaries or lipid metabolism could be demonstrated. The results support the hypothesis of thresholds for induction of adaptation processes in muscle skeletal tissue depending on the intensity of the exercise stimulus.
Adipose Tissue↗
Jogging or walking--comparison of health effects.
The present study compared the different health effects of 6 months' endurance training at two exercise intensities. Seventy-five nonsmoking, sedentary men were randomly assigned to either a home-based, unsupervised exercise program of 4 x 30 min/wk jogging at an intensity of 75% VO2max (n = 28), or of 6 x 30 min/wk walking at an intensity of 50% VO2max (n = 28), or to an inactive control group (n = 19). Exercise adherence and injuries related to exercise training as well as changes in endurance capacity, body fat, and serum lipids were assessed. After 6 months, joggers and walkers showed a similar increase in VO2max as measured by a maximal bicycle ergometer test (2.9 +/- 4.1 ml/kg min, P < 0.01 and 2.5 +/- 5.7 ml/kg min, P < 0.5, respectively). There were no significant changes in blood lipids in either group, although results revealed a significant association between the amount of training (i.e., kilometers exercised) and the increase in high-density lipoprotein-cholesterol (HDL-C) in joggers (Pearson's r = 0.42, P < 0.05). In walkers, a significant association between the amount of exercise and the decrease in sum of skinfolds and the waist-hip ratio was observed (Pearson's r = -0.48 and -0.45, P < 0.05 for both). The adherence rate was similar for both training groups with respect to the prescribed intervention goal with an average of 90 +/- 41 min/wk (joggers) and 121 +/- 72 min/wk (walkers) spent on endurance training.(ABSTRACT TRUNCATED AT 250 WORDS)
Adipose Tissue↗
[Body fat distribution: independent factor affecting the blood lipid profile].
The association of life style factors with profiles of blood lipids is described in a cohort of 75 middle aged (41.2 +/- 7.8 years) physically inactive, nonsmoking employees. The importance of body fat distribution in relation to relative body weight and the lipid profiles was also studied. The strongest possible predictor for an atherogenic lipid fraction was the quotient of abdominal and hip circumferences indicating an abdominal fat accumulation. In the group with the lowest quotient (< 0.84) the triglyceride and cholesterol values were lower by 43% and 13% respectively than in that with the highest quotient (< 0.88). The body mass index (BMI) gave the best inverse correlation with HDL-c and Apo A-I: Men with a BMI < 23.7 kg/m2 had in the average a HDL-c concentration 0.2 mmol/l higher than slightly overweighted men (BMI > 25 kg/m2). Physical inactivity and a reduced physical endurance were both associated with significantly higher total cholesterol and Apo B values. In a multivariate analysis the quotient of abdominal and hip circumferences, physical activity and endurance together with adherence to recommended nutritional behaviour explained approximately one third of the variations in LDL and Apo-B concentrations. This study thus confirms in a cohort of non smoking middle aged employees the predictive character of unfavorable life style for an atherogenic lipid profile. The assessment of body fat distribution added further information on the lipid profile that could not be detected by body size and weight determination alone.(ABSTRACT TRUNCATED AT 250 WORDS)
Adipose Tissue↗
Human skeletal muscle fibre types and force: velocity properties.
It has been reported that there is a relationship between power output and fibre type distribution in mixed muscle. The strength of this relationship is greater in the range of 3-8 rad.s-1 during knee extension compared to slower or faster angular knee extensor speeds. A mathematical model of the force: velocity properties of muscle with various combinations of fast- and slow-twitch fibres may provide insight into why specific velocities may give better predictions of fibre type distribution. In this paper, a mathematical model of the force:velocity relationship for mixed muscle is presented. This model demonstrates that peak power and optimal velocity should be predictive of fibre distribution and that the greatest fibre type discrimination in human knee extensor muscles should occur with measurement of power output at an angular velocity just greater than 7 rad.s-1. Measurements of torque:angular velocity relationships for knee extension on an isokinetic dynamometer and fibre type distribution in biopsies of vastus lateralis muscles were made on 31 subjects. Peak power and optimal velocity were determined in three ways: (1) direct measurement, (2) linear regression, and (3) fitting to the Hill equation. Estimation of peak power and optimal velocity using the Hill equation gave the best correlation with fibre type distribution (r < 0.5 for peak power or optimal velocity and percentage of fast-twitch fibres). The results of this study confirm that prediction of fibre type distribution is facilitated by measurement of peak power at optimal velocity and that fitting of the data to the Hill equation is a suitable method for evaluation of these parameters.
Biopsy↗
[Significance of life style factors for the blood lipids profile in bank employees].
In a study sample of 75 sedentary, non-smoking male bank employees (mean age 41.2 +/- 7.8 years) the relationship between lifestyle characteristics and serum lipid concentrations were examined. According to the mortality statistics of the canton of Zurich, this population is at increased risk for coronary heart disease. Statistical analyses confirmed the predictive character of physical activity for serum lipid levels. A low level of physical activity was associated with significantly higher concentrations of apolipoprotein B and LDL-C (Pearson coefficient of correlation r = -0.38, p < 0.001 and r = -0.35, p < 0.01, respectively). Accumulation of upper body fat (estimated by the waist to hip ratio) revealed to be a better predictor of lipid levels than body mass index and showed highly significant positive correlations with atherogenic lipid fractions. The most pronounced differences were seen for triglyceride levels, where the subgroup of subjects in the lowest tertile of waist-hip ratio showed about 40% lower triglyceride values compared to the highest waist-hip ratio tertile. In a study population of self-selected, non-smoking men, high levels of LDL-C and apolipoprotein B could partially be explained by unfavourable life style characteristics, particularly physical inactivity. The waist-hip ratio, characterizing abdominal fat accumulation, proved to be a good indicator of an atherogenic lipid profile. Measuring waist-hip ratio in medical routine examinations should thus be considered.
Adult↗
Relationship of physical activity, body fat, diet, and blood lipid profile in youths 10-15 yr.
The relationship between risk factors for CHD such as physical activity, cardiovascular fitness, subcutaneous body fat, dietary intake characteristics, age, and sex with the blood lipid profile was examined in 39 boys and 58 girls aged 10-15 yr. In boys, a high level of physical activity was related to higher concentrations of HDL-C (r = 0.32, P < 0.05), as well as to lower concentrations of VLDL-C, total triglycerides (TG), and the ratio of total cholesterol (TC) to HDL-C (r = -0.42; -0.40, both P < 0.01; and -0.37, P < 0.05). A high sum of 10 skinfolds (sigma 10SF) was related to a higher ratio of TC/HDL-C (r = 0.35; P < 0.05). In girls, physical activity was positively related to HDL-C (r = 0.29; P < 0.05). The sigma 10SF showed a negative association with Apo A-I and HDL-C (r = -0.26, -0.29, both P < 0.05) and a positive association with apolipoprotein B (Apo B) (r = 0.28, P < 0.05). Cardiovascular fitness was not significantly related to any of the blood lipid concentrations, in either boys or girls. Intake of saturated fats and dietary cholesterol was positively related to TC levels in boys, but the associations failed to reach statistical significance (r = 0.34 and r = 0.31, P > 0.05) due to the small sample size (N = 32).(ABSTRACT TRUNCATED AT 250 WORDS)
Adipose Tissue↗
Muscle fiber type distribution as estimated by Cybex testing and by muscle biopsy.
The purpose of the present study was to derive a regression equation relating variables obtained from a series of noninvasive functional tests in a normal subject population to the fiber type distribution of vastus lateralis muscle (VL) determined using muscle biopsy. All functional tests were designed to distinguish between basic properties of Type II fibers (fast twitch fibers) and Type I fibers (slow twitch fibers) and included assessment of peak torque, power output at nine different angular velocities (60 degrees.s-1 to 300 degrees.s-1), as well as a fatigue test consisting of 60 consecutive contractions at 90 degrees.s-1 to establish fatigue resistance of the knee extensor muscles. Using a stepwise multiple regression procedure, relative torque after 53-55 contractions (T55) in the fatigue test and power output at an angular velocity of 280 degrees.s-1 normalized for fat free mass of the thigh (FFMT) were the best predictors for fiber type distribution, explaining 51.8% of the variance in the proportion of Type II fibers in VL. No other measured variable met entering criteria. Subgroup analyses revealed a higher peak torque/FFMT, higher power/FFMT values at angular velocities of 200 degrees.s-1 and higher, and lower relative torque beyond 30 contractions in the fatigue test for the fast twitch group, FTG (subjects with > 60% Type II fibers, N = 8) as compared with the STG (subjects with < 45% Type II fibers, N = 9). Results from the present study suggest that two simple functional tests on a Cybex dynamometer yield reasonable estimates of the fiber type distribution in VL.
Adult↗
Little effect of long-term, self-monitored exercise on serum lipid levels in middle-aged women.
To study the effect of long-term, self-monitored exercise on physical fitness and serum lipid levels of middle-aged, nonsmoking females, a controlled study was conducted in 33 sedentary Swiss women. Seventeen women were randomly allocated to jog 2h/wk for 4 months on an individually prescribed and heart rate controlled base, whereas 16 women served as controls. Although leisure-time physical activity increased significantly in exercisers compared to controls, the average running distance of 10.9 km/wk was somewhat less than expected. The "net decrease" (4-month change in exercisers minus 4-month change in controls) in the sum of four skin-folds was -4.85 mm (p < 0.05). Four-month changes in serum lipids were generally small and nonsignificant. For example, the net decrease in total triglycerides was -0.2 mmol/l (p = 0.13). Correlational analyses revealed significant associations between changes in the waist-hip ratio and changes in total cholesterol (total-C) or the HDL/total-C ratio (r = 0.44, p < 0.01 and r = -0.29, p < 0.05, respectively). An increase in endurance capacity was associated with an increase in the HDL2-subfraction and in the ratio of HDL/total-C (r = 0.46, p < 0.05 and r = 0.52, p < 0.01). Multivariate linear regression analyses confirmed a change in endurance capacity as the statistically strongest positive predictor of changes in HDL, HDL2 and the HDL/total-C ratio. However, women who used oral contraceptives did not show any favourable lipid changes despite a considerable improvement in endurance capacity. The present training study in healthy, habitually sedentary middle-aged women was not able to show the same beneficial changes in serum HDL concentration as seen in male counterparts, when analyzed according to the principle of intention-to-treat. Exploratory analyses revealed that a too low jogging activity as well as a confounding effect of oral contraceptive use may partially account for the lack of significant changes in serum lipid levels after training.
Adult↗
[Effects of jogging on mental well-being and seasonal mood variations: a randomized study with healthy women and men].
The long-term effect of jogging on mental well-being and seasonal mood variation was examined in a randomized, controlled intervention study with healthy, middle-aged, sedentary, non-smoking, white collar subjects. 17 women and 39 men were allocated to jog 2 h/week for 4 months, whereas 16 women and 22 men served as controls. After 4 months, there was a partial cross-over with the controls now taking up jogging. After 8 study months, all 38 subjects of the second jogging intervention as well as 10 women and 30 men of the first 4-month jogging period were re-examined for the second time. All participants in the second re-examination were mailed a survey questionnaire one year after beginning of the study (response rate 83%). Despite varying adherence for the exercise regimen, the 4-month "net effects" (i.e. effect in exercise group minus effect in control group) showed a significant improvement in physical fitness (endurance capacity, resting heart rate) in men, but not in women. Among the mood scales assessed, "anger" showed a marginally significant effect in men (relative decrease; p = 0.05) and "calmness" a significant effect in women (relative increase; p = 0.02); after exclusion of 4 non-compliers from analysis in women, also "vigor" (relative increase; p = 0.03) and "depressiveness" (relative decrease; p = 0.02) were significantly improved after jogging. In women, the number of kilometers run was significantly correlated with an improvement in mental well-being (Pearson's r = 0.32 with change in 4 "positive" mood scales and r = 0.57 with change in 4 "negative" mood scales). Changes in endurance capacity were not significantly related to changes in mental well-being. However, in both women and men these mental effects of jogging were superposed by clear seasonal variations in mood, i.e. by a deterioration of mental well-being during the winter months and by a slow "remission" during summer. Taking jogging-induced and seasonal effects on mood together, the magnitude of the 1-year variability in mental well-being was somewhat attenuated in those study groups jogging, with this "buffering" effect reaching statistical significance in women (p = 0.050). We conclude from this training study with normal subjects that regular jogging of approximately 10 to 15 km/week may help to diminish the deterioration of mood observed during winter months (e.g. increase in depressiveness), especially in women. Hereby, a training-induced increase in endurance capacity is apparently not a prerequisite for this long-term mental effect of jogging.
Adult↗
Effects of long-term, self-monitored exercise on the serum lipoprotein and apolipoprotein profile in middle-aged men.
To study the effects of long-term, self-monitored exercise on the serum lipid profile and body composition of middle-aged non-smoking males, a controlled study was conducted in 61 sedentary, middle-class Swiss men. Thirty-nine men were randomly allocated to jog 2 h/wk for 4 months on an individually prescribed, heart rate-controlled basis, whereas 22 men served as controls. Despite varying adherence to the exercise regimen, the following 4-month net changes (effect in exercise group minus effect in control group) in lipids were seen: HDL cholesterol (C) +0.12 mmol/l (95% CI 0.02, 0.22; P = 0.028), LDL-C +0.08 mmol/l (ns), VLDL-C -0.26 mmol/l (-0.45, -0.07; P = 0.009), total triglycerides (TT) -0.21 mmol/l (ns), HDL-C/total C +0.02 (0.001, 0.05; P = 0.047). The net changes in endurance capacity and resting heart rate in favour of exercisers were significant as well, whereas no significant changes in apolipoprotein levels were seen. Exploratory analyses revealed, for example, associations of the increase in total physical activity with an increase in the HDL-C/total C ratio (r = 0.46; P less than 0.001), and of the change in estimated body fat content with an opposed change in the HDL-C/total C ratio (r = -0.40; P less than 0.001), or an inverse relationship of the change in subcutaneous fat with a change in the HDL2-C level (r = -0.39; P less than 0.001). Multivariable regression analysis suggested that much of the effect of jogging on HDL-C was apparently mediated through a decrease in body fat content. A change in the waist/hip ratio was unrelated to lipoprotein changes but was related to the change of TT level (r = 0.22; P less than 0.05). This study confirms that individually prescribed, unsupervised jogging can increase HDL-C levels and improve the serum lipoprotein profile in self-selected nonsmoking males. Although the effect is modest, it may be relevant to preventive cardiology, given the evidence for a reduction in cardiovascular risk even after apparently small decreases in risk factor levels.
Age Factors↗
Effects of self-monitored jogging on physical fitness, blood pressure and serum lipids: a controlled study in sedentary middle-aged men.
To study the effects of long-term, home-based exercise on physical fitness and cardiovascular risk factors of middle-aged nonsmoking males, a controlled study was conducted in 61 sedentary Swiss men. Thirty-nine men were randomly allocated to jog 2 h/week for 4 months on an individually prescribed and heart-rate-controlled basis, whereas 22 men served as controls. Despite varying adherence to the exercise regimen, the 4-month net change (effect in exercise group minus effect in control group) in estimated endurance capacity was significant and positive. Net changes in arterial blood pressure, measured with a random-zero device, were nonsignificant, but after exclusion of low-normotensive men (n = 19) from analysis, a significant net effect of exercise on diastolic blood pressure was seen (-4.3 mmHg; p = .048). The following net changes in serum lipid levels occurred: HDL cholesterol + 0.12 mmol/l (p = .028), total triglycerides -0.21 mmol/l (ns), HDL-C/total cholesterol ratio +0.02 (p = .047). Exploratory analyses revealed that an increase in estimated endurance capacity was associated with a rise in systolic and diastolic blood pressure (r = 0.49 and 0.43, respectively; p less than 0.01 both). Changes in the waist-hip ratio were directly related to the change in diastolic blood pressure (r = 0.27; p less than 0.05). Multivariable analysis indicated that much of the beneficial effect of exercise on diastolic blood pressure was apparently mediated through a decrease in body fat. This study confirms that individually prescribed jogging can reduce cardiovascular risk factors in self-selected nonsmoking males.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Anthropometric and lifestyle correlates of serum lipoprotein and apolipoprotein levels among normal non-smoking men and women.
The relationship between serologic predictors of coronary risk and anthropometric as well as lifestyle characteristics was investigated in 61 men (37.5 +/- 8.5 yrs) and 33 women (40.1 +/- 9.0 yrs). All subjects were healthy non-smokers, mostly middle-class bank employees. In bivariate analysis, among both genders the ratio of waist-to-hip circumference (WHR) was the single best predictor of levels of serum LDL-cholesterol, apolipoprotein B, VLDL-cholesterol and triglycerides (positive association) as well as HDL-cholesterol and apolipoprotein A-I (inverse association). In men, body fat as estimated from bioelectrical impedance measurement was the second best predictor of lipoprotein and apoprotein concentrations, whereas in women it was the body mass index (BMI). The additional independent predictive power of WHR and body fat for the lipid profile was tested in multivariate analysis by adding WHR and body fat sequentially to regression models containing already BMI, endurance capacity, exercise, alcohol consumption and age. For example, explained variance of triglyceride distribution rose from 26.3 to 35.1% (P = 0.01 for increase) when body fat was entered into the regression equation, or inclusion of WHR into a model already containing age, the behavioral variables, BMI, and body fat increased the explained variance of LDL/HDL-cholesterol ratio from 20.9 to 27.6% (P = 0.04 for increase). In women, the same regression models were even slightly more predictive for the serum lipid profile. Endurance capacity was related to a low atherogenic risk lipid profile in bivariate analysis but lost much of its predictive power in multivariate analysis, which confirms that the effect of fitness on lipid levels is probably mediated in part by a low body fat content. It is concluded from this cross-sectional investigation that studies which focus on associations between lifestyle and serologic predictors of atherogenic risk should possibly include the WHR and a measure of body fat, since the latter two appear to be closer correlates of serum lipoprotein and apolipoprotein levels than BMI or single behavioral factors, at least among male non-smokers.
Adipose Tissue↗
Effects of long-term, moderate exercise on body composition and serum lipid profile: a controlled study in middle-aged Swiss men and women.
Explore the source record for details and available documents.
Adult↗
AVLINE: a data base and critical review system of audiovisual materials for the education of health professionals.
The AVLINE data base, operated by the National Library of Medicine, was designed to aid in the selection, use, and sharing of quality audiovisual material in the education of health professionals and to promote the quality production of such materials. AVLINE provides standardized bibliographic and critical review information in both online and printed catalog form. In this report the evolution of AVLINE is traced, and the development of its companion review system is examined.
Audiovisual Aids↗
Continuing education of health professionals: proposal for a definition of quality.
The present reality of continuing education of health professionals is briefly reviewed: what it can and cannot do and how it differs from preparatory professional education. It is hoped that the application of educational theory and the analysis of the successes and failures of continuing education of the past will result in continuing education being an effective bridge between academia and practice. From a study of educational theory, of adult learning, of management, and of past experience, a model was developed. The model describes quality continuing education and encourages the health professional to assume personal responsibility for learning. The listed elements of quality can be used to introduce a measure of quality to the planning and implementation of continuing education activities. Agencies responsible for the quality of continuing education activities can use the elements to assess activities, products, and services.
Education, Medical, Continuing↗
Attributes of quality in audiovisual materials for health professionals.
Utilizing a series of meetings and incorporating individual efforts of producers, evaluators, and users of audiovisual materials; an attempt has been made to define the quality of an instructional item. Attributes of quality in content, instructional design, technical production, and packaging of audiovisual materials are addressed through questions about general criteria that permit expression of individual dictates off creativity and taste. These attributes of quality are intended for use by the producers and evaluators of audiovisual instruction.
Audiovisual Aids↗
Audiovisual materials.
Explore the source record for details and available documents.
Audiovisual Aids↗