0000000000591387
AUTHOR
S. Aunola
Strain of employees in the machine industry in Finland.
In order to investigate the strain of workers in different occupations of the Finnish machine industry, energy expenditure and heart rate of 190 men and 47 women employees were measured during their normal course of work. Work was most strenuous in occupations in the early stages of production and in unskilled jobs. The relative strain of semi-skilled workers was highest in the oldest age groups, over 45 years. It is concluded that when systems for grading the strain of industrial work are constructed, the long-term effects of work and workers' characteristics such as age, sex, weight and physical fitness should be taken into consideration.
The relation between cycling time to exhaustion and anaerobic threshold.
This study investigated whether the anaerobic threshold (AnT) could be used to predict prolonged work capacity measured as cycling time to exhaustion (= endurance time) and which factors, in addition to relative exercise intensity, could explain variation in endurance time. Theoretical exercise intensities corresponding to certain endurance times were also calculated. The hyperbolic and exponential functions between cycling time and relative work rate (WR[%]), as well as between cycling time and relative oxygen uptake (VO2[%]) were fitted to the pooled data (n = 45) of 17 subjects. The WR(%) and VO2(%) were expressed as a percentage of the subject's own AnT- and maximum-values. At WR corres…
Does anaerobic threshold correlate with maximal lactate steady-state?
The aim of this study was to compare the 'anaerobic threshold' (AnT) of subjects determined during a continuous 2-min incremental exercise test until exhaustion and the 'maximal lactate steady-state' (BLaSsmax) determined during prolonged exercise at constant loads corresponding to the subjects' AnT and/or 5-25% above and below it. Seventeen subjects performed an incremental exercise test and 1-5 prolonged exercise tests on a cycle ergometer until exhaustion at intervals of 1 week, and work rates, oxygen uptake (VO2) values and brachial venous blood lactate (BLa) levels were measured. It was proposed that when exercising at a constant workload below AnT, BLa would fall after having reached …
Muscle metabolic profile and oxygen transport capacity as determinants of aerobic and anaerobic thresholds
Aerobic and anaerobic thresholds determined by different methods in repeated exercise tests were correlated with cardiorespiratory variables and variables of muscle metabolic profile in 33 men aged 20–50 years. Aerobic threshold was determined from blood lactate, ventilation, and respiratory gas exchange by two methods (AerT1 and AerT2) and anaerobic threshold from venous lactate (AnTLa), from ventilation and gas exchange (AnTr) and by using the criterion of 4 mmol·l−1 of venous lactate (AnT4mmol). In addition to ordinary correlative analyses, applications of LISREL models were used. The 8 explanatory variables chosen for the regression analyses were height, relative heart volume, relative …
Reproducibility of aerobic and anaerobic thresholds in 20-50 year old men.
The reproducibility of the aerobic (AerT) and the anaerobic (AnT) threshold was studied in 33 men aged 20–50 years. They completed two maximal exercise tests on a bicycle ergometer. The thresholds, as $$\dot V_{O_2 }$$ (l·min−1), were determined visually by two investigators using both the blood lactate and the respiratory indices. The respiratory variables were measured with a computerized breath-by-breath method; samples of venous blood were drawn every 2nd min and analysed enzymatically for lactate. The reproducibility of the AerT (r=0.94) and of the AnT (r=0.96) were equally good. The AnT can be determined either from blood lactate concentrations (AnTLa) or from ventilatory and gas exch…
Role of skeletal muscle-fibre type in regulation of glucose metabolism in middle-aged subjects with impaired glucose tolerance during a long-term exercise and dietary intervention
Aim: The aim of this study was to investigate the role of skeletal muscle fibre type in the regulation of glucose metabolism in middle-aged obese subjects with impaired glucose tolerance (IGT) during a 2-year exercise anddietary intervention. Methods: Muscle biopsies (musculus vastus lateralis) were taken from 22 subjects belonging to the intervention group of the Finnish Diabetes Prevention Study [1]. According to their myosin heavy chain (MHC) profile at the baseline, the subjects were divided into two groups: IGT s l o w (n = 10) with a high proportion of MHC I isoforms and IGT f a s t (n = 12) with a high proportion of MHC II isoforms in the vastus lateralis muscle. The intervention con…