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Biomedical subjects

A C Linnerud

Publications and source records attributed to A C Linnerud.

13 recordsLinked to original sources
PubMed1976

Physical fitness levels vs selected coronary risk factors. A cross-sectional study.

Several studies show significant correlations of blood variables, weight, abnormal electrocardiograms, and blood pressure with the incidence of coronary heart disease, but the quantification of fitness and its correlation with coronary heart disease is more difficult. In this study, approximately 3,000 men, average age of 44.6 years, were examined for blood and lipid profile, pulmonary function, percent body fat determination, and Balke maximal performance treadmill stress testing with multilead ECG monitoring. Five age-adjusted cardiorespiratory fitness categories were determined from treadmill times. A consistent inverse relationship among physical fitness categories and resting heart rate, body weight, percent body fat, serum levels of cholesterol and triglycerides, glucose, and systolic blood pressure, was observed. Forced vital capacity was directly related to levels of fitness. These results, although cross-sectional, imply that physical fitness is related to lower coronary risk factors.

Adult↗
PubMed1976

A comparative analysis of four protocols for maximal treadmill stress testing.

The purpose of this investigation was to compare the results from four commonly used maximal treadmill stress tests: Balke, Bruce, Ellestad, and a continuous multistage running protocol. The results compared serial and maximal heart rate, metabolic demands, and ECG determinations. Fifty-one healthy men, 35 to 55 years of age, volunteered for this study and were dichotomized into trained and untrained subjects. Regression analyses showed all the tests to correlate highly. No significant differences were found between tests at maximum for V02, heart rate, and blood pressure, except for V02 for the Balke as compared to the running protocol (39 vs. 41 ml./Kg-min). The Balke protocol showed lower values at maximum in VE and RP than the other three tests as well as the most gradual rate of progression in MET cost (0.5 METS per minute). The increase for the Bruce and Ellestad tests was from 1 to 1.5 METS per minute, and a rapid initial increase (9 METS in the first 3 minutes) made the running test undesirable as a screening method. Although serial plots of heart rate and MET costs were similar to those previously reported for different population samples, the present data further refined these values. Finally, a nomograph comparing treadmill time and V02, max. for the Balke, Bruce, and Ellestad tests was developed from these data.

Adult↗
PubMed1976

Physiologic responses of men 49 to 65 years of age to endurance training.

A study was made of the effects of training for 30 minutes, three days a week for 20 weeks on certain physiologic measures of sedentary men between 49 and 65 years of age. Twenty-two subjects volunteered for the experimental group, and 8 others for the control group. Exercise sessions were conducted on a quarter-mile track and consisted of continuous bouts of walking and jogging. The average daily energy expenditures progressed from 228 to 365 kilocalories between weeks 4 and 20. For the same period, average exercise heart rates (HRs) progressed from 149 beats/minute (83 per cent maximum HR) to 155 beats/minute (91 per cent maximum HR). The experimental group showed significant increases in maximum oxygen intake (VO2 max) from 2.47 to 2.90 liters/minute (18 per cent) and in maximum pulmonary ventilation (VE max) from 105 to 121 liters/minute (BTPS), and decreases in resting HR, diastolic blood pressure, body weight, skinfold fat, and abdominal girth. Serum cholesterol and triglyceride levels and heart volume remained unchanged. The control subjects showed no significant changes. Regression analysis, with use of age as a covariate, showed a small but significant inverse relationship with changes in VO2 max. It was concluded that men of the 49-65 age group respond favorably to endurance exercise and show a magnitude of change similar to that found in previous investigations of similar design with younger subjects.

Age Factors↗
PubMed1976

Prediction of body density in young and middle-aged men.

The purpose of this investigation was to predict body density of young (18-22 yr) and middle-aged (40-55 yr) men and to determine if generalized equations were appropriate to both populations. The dependent variable, body density, was determined by the hydrostatic technique. Independent variables included 7 skinfold fat, 11 girth, and 7 diameter measures; age; height; and weight. Mean body density for young men was 1.068 g/ml (SD +/- 0.014) and percent fat, 13.4 (SD +/- 6.0); the values for middle-aged subjects were 1.043 g/ml (SD +/- 0.0130) and 24.7% (SD +/- 5.9). Incomplete principal components analysis was used to examine the dimensions measured by the independent variables, and these analyses revealed differences between samples. Using multiple regression analysis, with the exception of girth measurements, the slopes of the regression lines were equal. For all analyses, however, the intercepts were different. These results confirmed the need for different regression equations for these populations. The most accurate prediction for young men was with two skinfold, four girth, and two diameter measures (R = 0.88; SE = 0.0069 g/ml); two skinfold and three girth measures accurately predicted body density for middle-aged men (R = 0.84; SE = 0.0074 g/ml).

Adipose Tissue↗
PubMed1975

Prediction of body density in young and middle-aged women.

The purpose of this investigation was to predict body density of young and middle-aged women and to determine if the use of a greater variety of variables, particularly those for fat in the bust and hip regions, increases the predictability of body density. Body density determined by the hydrostatic technique (dependent variable) was obtained from 83 volunteer young women and 60 middle-aged women ranging from 18 to 22 and 33 to 50 yr of age, respectively. Independent variables included 8 skinfold, 13 girth, and 7 diameter measures; age; height; weight; and bra and cup sizes. Mean body density for young women was 1.043 g/ml (SD plus or minus 0.014) and percent fat, 24.8 (SD plus or minus 6.4); 1.031 g/ml (SD plus or minus 0.015) and 29.8% (SD plus or minus 6.7) for middle aged subjects. Percent fat was calculated by the formula of Siri. Factor analysis was used to examine the dimensions measured by the independent variables as a function of age. A multiple regression model was used to develop predictions of body density from the independent variables. The best combination of four variables for predicting body density was skinfold thigh, skinfold suprailiac, cup size, skinfold suprailiac, girth waist, and skinfold thigh (R = 0.89) for middle-aged women. The data showed that the highest predictons were found by using combinations of skinfold, girth, and diameter variables; cup size also supported the need for different regression equations for different age groups.

Adolescent↗
PubMed1975

Frequency of training as a determinant for improvement in cardiovascular function and body composition of middle-aged men.

Frequency, duration and intensity of training have been shown to be important determinants for improving various physiological functions. This report represents a series of six training investigations conducted by the investigators over the past seven years. Within the six investigations ten separate groups were studied. These data were combined and tabulated to look at frequency of training as a determinant for improving cardiovascular function and body composition of middle-aged men. The subjects included 148 healthy, sedentary, volunteer men ranging from 28 to 64 years of age (x equal to 41). The experiments were carefully controlled and included running 30 to 45 minutes for two (four groups), three (three groups) or four (three groups) days each week for 20 weeks. The results show that all frequencies had a significant effect on cardiovascular function, but only three and four days/week regimens showed reduction in total body weight and fat. Changes in maximum oxygen consumption (VO2 max) were similar for two and three days/week programs, and significantly greater for four days. The data support the notion of frequency of training being an important criterion for improving cardiovascular function and body composition.

Adipose Tissue↗
PubMed1975

Effects of mode of training on cardiovascular function and body composition of adult men.

The purpose of this investigation was to determine the comparative effects on middle-aged men of training by running, walking, and bicycling. Sedentary men (X age = 38 yrs), who volunteered to participate, were assigned randomly to one of the following training groups: I, running (n = 9); II, walking (n = 9); and III, bicycling (n = 8). All groups trained for 30 min, 3 times/week for 20 weeks at 85 to 90% of maximal heart rate. A control group of seven men of similar qualifications also were evaluated. Training heart rates averaged 90%, 87%, and 87% of maximum for groups I, II, and III, respectively. All experimental groups improved significantly in cardiovascular and body composition measures. The former was shown by significant increases in Vo2max, VEmax, and O2 pulse and a significant decrease in resting heart rate. Body composition results showed that the experimental groups had a significant reduction in body weight, skinfold fat, and abdominal girth measurements. The control group showed no significant changes for any of the variables. It was concluded that improvement in the experimental groups was independent of mode of training.

Adult↗