Effects of meal and its electrolytes on bioelectrical impedance.
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Adult↗
Biomedical subjects
P Oja
Publications and source records attributed to P Oja.
Precision of dual energy x-ray absorptiometry in the upper extremities.
Dual energy x-ray absorptiometry (DEXA) has been shown to be a precise method for measuring bone mineral density (BMD) and content (BMC) in lumbar spine and proximal femur, but it has not been widely used in other skeletal sites. The in vivo day-to-day precision of DEXA (Norland XR-26) for seven anatomic sites in the upper extremities was evaluated by twice measuring both the right and left sides in ten subjects. For consistently defined regions-of-interest, the following precision values (coefficient of variation) were obtained for BMD and BMC: 0.8% and 1.0% (proximal humerus); 0.5% and 0.5% (humeral shaft); 0.7% and 0.5% (radial shaft); 1.3% and 1.1% (ulnar shaft); 0.7% and 1.0% (distal radius); 0.7% and 1.2% (distal ulna); 0.4% and 0.6% (hand). The initially observed relative side-to-side differences did not change significantly in the repeated measurements. Our results indicate that DEXA is a precise method for assessment of BMD and BMC also in the upper extremities.
Absorptiometry, Photon↗
Bone mineral density of female athletes in different sports.
Anthropometry, training history, cardiorespiratory and muscular performance capacity, and bone mineral density (BMD) were studied in female orienteers (n = 30), cross-country skiers (n = 28), cyclists (n = 29), weight lifters (n = 18) and in a reference group (n = 25). BMD was measured at lumbar spine, femoral neck, distal femur, patella, proximal tibia, calcaneus and distal radius by dual energy X-ray absorptiometry. The weight lifters had significantly higher weight adjusted BMD (P < 0.001) than the referents at all sites (9-26%) except in femoral neck and calcaneus. Of the endurance athletes, the orienteers were the only group which had significantly higher BMD (P < 0.05) than referents, only at distal femur (5%) and proximal tibia (5%). BMD did not differ significantly at any skeletal site between subjects with different calcium intake. Weight training seems to provide more effective osteogenic stimulus than endurance training. The differences in BMD at different sites between the groups were consistent with specificity of the stimulus to the training of the studied sports.
Adult↗
A cruciate ligament injury produces considerable, permanent osteoporosis in the affected knee.
Bone mineral density (BMD) and clinical status of 42 patients treated surgically 10-11 years earlier for an acute knee ligament injury were determined. The BMD was measured at the spine (L2-4) and the femoral neck, distal femur, patella, proximal tibia, and calcaneus of both lower extremities using dual-energy x-ray absorptiometric (DXA) scanner. The relative BMD results of the injured knee were correlated with sex, age, activity level, knee stability, and functional scores of the patient. In the 11 patients with moderate injury (isolated rupture of the medial collateral ligament), the BMDs of the injured and uninjured extremities were equal. In the 31 patients with severe injury (cruciate ligament rupture), the BMDs were significantly lower in the injured knee: distal femur, -6.0% (p = 0.0000); patella, -9.0% (p = 0.0000); and proximal tibia, -3.3% (p = 0.0012). Neither the femoral neck nor the calcaneus showed any differences. There were no significant differences either between men and women or between patients with different activity levels. The relative BMDs of the injured knee did not correlate with age or static knee stability but correlated significantly (r = 0.42-0.78, p < 0.01-0.001) with the functional scores of the same knee: the better the knee function in comparison with the healthy knee, the higher the relative BMD. The spinal BMDs corresponded with the age-adjusted reference values of the used densitometry. In conclusion, a severe knee ligament injury results in permanently decreased BMD in the injured knee. Other parts of the same extremity and lumbar spine are not affected.(ABSTRACT TRUNCATED AT 250 WORDS)
Absorptiometry, Photon↗
Evaluation of a model for prediction of lumbar bone mineral density.
A mathematical model with adequate clinical accuracy would be useful for predicting life-long bone mass behaviour in various skeletal sites. We have tested the performance of a multivariate nonlinear model, recently developed by an Italian research group for predicting lumbar bone mass and density, in a sample of 239 pre- or post-menopausal healthy Finnish women whose lumbar bone mineral density (BMD) was determined by dual-energy X-ray absorptiometry. The model, which was based on height, weight, body mass index, age and years since menopause, predicted poorly (R-squared = 0.14) the measured BMD. Furthermore, it compressed strongly the actual variation of the BMD values resulting in a considerable overestimation or underestimation (about 30%) of low or high BMD values, respectively. Our results indicated that the predictive value of a simple model is not clinically acceptable and therefore the usefulness of this kind of model remains questionable.
Absorptiometry, Photon↗
Feasibility of a 2-km walking test for fitness assessment in a population study.
A simple 2-km Walking Test has been developed for determining the cardiorespiratory fitness of healthy adults. In the present study the following aspects of the feasibility of this test for population assessment were investigated: participation willingness, the percentage of test qualified subjects, the percentage of acceptable test performances and the resources needed for field test administration. A representative sample was drawn from the 27 to 65-year-old population in a rural municipality in northeastern Finland. Subjects were recruited on the basis of the results of health questionnaires and interviews. One fourth of the volunteers were excluded from the test because of health problems. The 2-km walking tests were administered outdoors in the municipality center. More than 50% of the subjects successfully completed two consecutive walking tests. This study indicated that the 2-km Walking Test is a feasible alternative as a measure of cardiovascular fitness for large population groups and could potentially be used in exercise related health promotion programmes.
Adult↗
Validity of a two kilometre walking test for estimating maximal aerobic power in overweight adults.
In our earlier study a regression model, with heart rate and time in a 2 km fast walk, body mass index (BMI) or weight (kg) and age as explanatory variables, explained 75% of the variation in the VO2max of adults with normal weight. The present study was designed to test whether the prediction model based on a 2km fast walk and simple site measurements is valid in estimating the VO2max of overweight men and women and to compare 1km and 2km test distances. Forty-five women and thirty-two men, BMI 27-40, aged 20-65 years, with no cardiorespiratory or musculoskeletal restrictions for a maximal stress test and fast walk, were studied. The VO2max was determined in an uphill walk to maximal effort on a treadmill. Two walking tests, 1km and 2km, were conducted on a flat dirt road. Heart rate was recorded during the walks, and the mean rate during the last 30 seconds was used in the model. The correlation coefficients between the measured and predicted VO2max in the 2km test were 0.77 for the women and 0.75 for men, corrected for body weight (ml/kg/min), and 0.77 and 0.69 respectively in absolute values (1/min). These results suggest that the 2km walk test previously developed for adults within normal weight limits is a reasonably valid test of the cardiorespiratory fitness of overweight, but otherwise healthy, women and men.
Adult↗
Precision of dual-energy x-ray absorptiometry in determining bone mineral density and content of various skeletal sites.
Repeated measurements of bone mineral density (BMD) by dual-energy x-ray absorptiometry (DEXA) reliably indicate changes in the bone mineral content (BMC) of the lumbar spine and proximal femur, but its applicability to other sites has not been properly determined. The in-vivo day-to-day precision of DEXA (Norland XR-26) for lumbar spine, femoral neck, distal femur, patella, proximal tibia, calcaneus and distal radius was evaluated for 15 subjects who were scanned three times for 2 wk. Intra- and interobserver errors were also determined for image analysis. For clearly defined regions of interest, the following precision values were obtained for BMD with low intra- and interobserver error: 1.7% (lumbar spine), 1.3% (femoral neck), 1.2% (distal femur), 1.0% (patella), 0.7% (proximal tibia), 1.3% (calcaneus) and 1.9% (distal radius). The precision for BMC was lower. The results indicate that DEXA can successfully and precisely measure BMD of sites not commonly assessed by this technique.
Absorptiometry, Photon↗
Training effects of cross-country skiing and running on maximal aerobic cycle performance and on blood lipids.
Two experiments were carried out to compare the cardiorespiratory and metabolic effects of cross-country skiing and running training during two successive winters. Forty-year-old men were randomly assigned into skiing (n = 15 in study 1, n = 16 in study 2), running (n = 16 in study 1 and n = 16 in study 2) and control (n = 17 in study 1 and n = 16 in study 2) groups. Three subjects dropped out of the programme. The training lasted 9-10 weeks with 40-min exercise sessions three times each week. The training intensity was controlled at 75%-85% of the maximal oxygen consumption (VO2max) using portable heart rate metres and the mean heart rate was 156-157 beats.min-1 in the training groups. In the pooled data of the two studies the mean increase in the VO2max (in ml.min-1.kg-1) on a cycle ergometer was 17% for the skiing group, 13% for the running group and 2% for the control group. The increase in VO2max was highly significant in the combined exercise group compared to the control group but did not differ significantly between the skiing and running groups. The fasting serum concentrations of lipoproteins and insulin did not change significantly in any of the groups. These results suggested that training by cross-country skiing and running of the same duration and intensity at each session for 9-10 weeks improved equally the cardiorespiratory fitness of untrained middle-aged men.
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A 2-km walking test for assessing the cardiorespiratory fitness of healthy adults.
A simple walking test was developed with 159 (females = 80, males = 79) healthy 20-65-year-old subjects. All the subjects first walked the distances of 1.0, 1.5 and 2.0 km on a flat dirt road. Half of the participants were tested in the laboratory for maximal oxygen uptake (VO2max), and the 2-km test was repeated again twice. In a comparison of the three distances, the 2-km test was repeatable, the most preferable subjectively and the most accurate in predicting VO2max. A sex-specific prediction model including walking time, heart rate at the end of the walk, age and body mass index predicted 73-75% of the variance in VO2max (ml.kg-1.min-1) and that with body weight 66-76%, with a standard error of estimate of the order of 9-15% of the mean. The cross-validation of the models yielded reasonable accuracy in obese men and women and in moderately active men, and less accuracy in moderately active women and highly active men. These results suggest that a fast 2-km walk supplemented with simple measurements is a feasible and accurate alternative for determining the cardiorespiratory fitness of healthy adults.
Adult↗
[Exercise in the treatment and prevention of obesity].
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Animals↗
Haemodynamic and hormonal responses to heat exposure in a Finnish sauna bath.
Eight healthy young men were studied during three periods of heat exposure in a Finnish sauna bath: at 80 degrees C dry bulb (80 D) and 100 degrees C dry bulb (100 D) temperatures until subjective discomfort, and in 80 degrees C dry heat, becoming humid (80 DH) until subjective exhaustion. Oral temperature increased 1.1 degrees C at 80 D, 1.9 degrees C at 100 D and 3.2 degrees C at 80 DH. Heart rate increased about 60% at 80 D, 90% at 100 D and 130% at 80 DH. Plasma noradrenaline increased about 100% at 80 D, 160% at 100 D and 310% at 80 DH. Adrenaline did not change. Plasma prolactin increased 2-fold at 80 D, 7-fold at 100 D and 10-fold at 80 DH. Blood concentrations of the beta-endorphin immunoreactivity at 100 D, adrenocorticotropic hormone (ACTH) at 100 D and 80 DH, growth hormone at 100 D and testosterone at 80 DH also increased, but cortisol at 80 D and 100 D decreased. The plasma prostaglandin E2 and serum thromboxane B2 levels did not change. Patterns related to heat exposure were observed for heart rate, plasma noradrenaline, ACTH and prolactin in the three study periods.
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A new fitness test for cardiovascular epidemiology and exercise promotion.
The present study suggests that the 2-km walking test is relatively simple to administer by trained instructors, it is as accurate in predicting VO2 max as most available indirect methods, and it is socially acceptable for a normal population. Thus, the test seems to provide a feasible alternative for the testing of cardiovascular fitness in epidemiological research and exercise promotion.
Adult↗
Cardiorespiratory strain of middle-aged men in mass events of long-distance cycling, rowing, jogging, and skiing.
The heart rate of 11 39- to 53-year-old regularly exercising but nonathletic men was recorded during mass events of 132-km cycling, 35-km rowing, 33-km running, and 90-km cross-country skiing during 1 year. These measurements were related to the cardiorespiratory response in respective maximal exercise tests to determine and compare the strain of the four events. The mean event time of the subjects was 4 h 58 (+/- 34) min for cycling, 4 h 20 (+/- 35) min for rowing, 3 h 30 (+/- 29) min for running, and 8 h 29 (+/- 49) min for skiing. The respective mean heart rates were 153 (+/- 10), 137 (+/- 15), 159 (+/- 8), and 145 (+/- 5) bts/min, which represented 79.3 (+/- 6), 72.9 (+/- 13), 85.7 (+/- 4), and 72.8 (+/- 7) %VO2 max as determined from the event-specific HR/VO2 regression line. The proportion of event heart rates above the level representing the 90% event-specific maximal heart rate was 31.2% (+/- 19%) in cycling, 17.9% (+/- 26%) for rowing, 59.7% (+/- 24%) for running, and 21.6% (+/- 23%) for skiing. A statistical comparison of the mean event heart rates indicated that heart rate was lower in rowing than in jogging (P less than 0.01) and in cycling (P less than 0.05) and also lower in skiing (P less than 0.01) than in jogging. The present results showed that the cardiorespiratory strain of middle-aged nonathletic men during long-distance mass events of cycling, jogging, and skiing is high and relatively comparable to that of well-conditioned athletes.
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Comparison of three field methods for measuring oxygen consumption.
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Adult↗
Policemen's physical fitness in relation to the frequency of leisure-time physical exercise.
Ninety to ninety-five men (aged 27 to 46 years) from the police academy were the study subjects. Their prior habits of physical exercise, estimated aerobic capacity (VO2max), muscular performance, and thickness of subcutaneous fat were determined. The policemen were taller (181 cm vs 175 cm) and heavier (84 kg vs 74 kg) than the average 20- to 40-year-old Finnish man, and their VO2max (1 X min-1) was higher (3.41 1 X min-1 vs 2.96 1 X min-1). The frequency of prior physical exercise significantly correlated with most of the variables studied. Those policemen who did not exercise at all (n = 12) were inferior to the average 20- to 40-year-old Finnish man on all the physical fitness tests, whereas the results of the most active policemen (n = 23) were clearly higher. The results indicate that the selection of heavier and taller men for police training guarantees a certain absolute level of physical performance capacity. However, the physical activity involved in police work is insufficient to maintain a high level of physical fitness, which must be achieved through participation in regular and effective physical training.
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Oxygen consumption and heart rate in different modes of manual postal delivery.
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Adult↗
Heart rate as an estimator of oxygen consumption during manual postal delivery.
Nine young healthy postmen performed three progressive maximal exercise tests (on a bicycle ergometer and with and without a 10-kg shoulder bag on a treadmill) for which the least-squares regression equations of heart rate (HR) on oxygen consumption (VO2) were established. HR and VO2 were then measured during five modes of simulated postal delivery: on level ground by foot (F), bicycle (B), and push-cart (C) and on stairs by foot (S/F) and push-cart (S/C). The respective work HR values were inserted into the three regression equations established for HR/VO2, and VO2 was solved for. The estimated VO2 values tended to be systematically higher than the measured ones. The best regression proved to be that established for the treadmill plus mailbag; the regression coefficients between the measured and estimated VO2s were higher than 0.75, and the percentage differences between the means of the measured and estimated values were no more than 10% for F and B delivery. All the regressions yielded inaccurate estimations of VO2 for C, S/F and S/C delivery. It was concluded that HR is acceptable as an estimator of VO2 only when the test work closely resembles the muscle work in the job.
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