Long-term effects of different physical activity levels on coronary heart disease risk factors in middle-aged men.

In order to define the amount of physical activity appropriate in primary prevention of coronary heart disease (CHD), we have compared the effects during 5 years of physical activity in four groups of middle-aged men with different but stable approximate metabolic costs of leisure time sports activities (AMCSA): sedentary (n = 40; 0 kcal per week), low activity (n = 31; 1-999 kcal per week), moderate activity (n = 56; 1,000-1,999 kcal per week), and high activity (n = 71; > or = 2,000 kcal per week). Time related increase of body mass and BMI was more pronounced in lower activity groups. Changes in HDL cholesterol were more favourable in the high activity group as compared to sedentary and low activity groups. The increase of diastolic blood pressure (DBP) in the sedentary group was statistically significantly different from the decrease of DBP observed in both moderate and high activity groups. We conclude that favourable long-term stabilization of most coronary risk factors is achievable with physical activity energy expenditure above 1,000 kcal per week. Physical activity-related energy expenditure > or = 2,000 kcal per week is associated with some additional benefits, especially with a favourable modification of HDL cholesterol level.

Study on threshold dose of physical activity in coronary heart disease prevention. Part I. Relationship between leisure time physical activity and coronary risk factors.

This study performed on 146 healthy men aged 30-55 years involved in recreational training for several years has demonstrated a relationship between an approximate metabolic cost of leisure time sports activities with an energy expenditure greater than 5 kcal/min (greater than 21 kJ) and the total coronary risk score, % body fat, HDL cholesterol concentration, smoking frequency, and aerobic capacity indices. These data as well as the preliminary results of a long-term study demonstrate that regular endurance training with an exercise intensity greater than 5 kcal/min (greater than 21 kJ) and a total energy expenditure of 1000-1499 kcal/week (4187-6279 kJ) may be a threshold dose of exercise effective for prevention of coronary heart disease and promotion of health.

Erythrocyte 2,3-diphosphoglycerate (2,3-DPG) after submaximal exercise in human subjects.

In 79 swimmers aged 13--15 years the concentration of 2,3-DPG was determined in the erythrocytes at rest and 1 minute after the end of 7 minutes of submaximal exercise on an arm ergometer. In the examined subjects no significant changes were found in 2,3-DPG concentration in the erythrocytes. A non-significant tendency was demonstrated for a decrease in 2,3-DPG content of erythrocytes related to the post-exercise rise of blood lactate concentration.

[Physical efficiency of women employed in the knitting industry]. / Wydolnosc fizyczna kobiet zatrudnionych w przemysle dziewiarskim.

Physical efficiency in 184 spinners of a modern knitting plant has been examined by determining a maximum absorbtion of oxygen (VO2 max) using an indirect method of Astrand--Ryhming. A significant effect of age and consequently duration of employment on the decrease in physical efficiency level has been found. The distribution of efficiency index according to Astrand's classifications is not equal, which may result from a particular stereotype of motorial activity, especially non-occupational one.

The effect of physical exercise on 2,3-diphosphoglyceride (2,3-DPG) concentration in erythrocytes.

Concentration of 2,3-DPG was determined in erythrocytes of 30 young cyclists at rest, immediately after a strenuous physical exercise on a bicyle- ergometer, and then in 30th min rest following the exercise. It was found that exercise changes the concentration of 2,3-DPG in the erythrocytes and the trends of these changes were different depending on endurance of the subjects examined. In the subjects with higher endurance a tendency was observed for decreasing concentration of 2,3-DPG immendiately after the exercise with a futher significant fall after a 30 min rest. On the other hand, in the subjects with lower endurance the erythrocyte 2,3-DPG concentration rose after the exercise and returned to its initial value at 30 min of rest.