Activity level

Abstract: A typical aspect of aging is the increase in variability of a feature within a population, suggesting individual variation in the decline with age. The decline is probably inevitable (predisposed), but some show slower declines than others. Physical activity might be one of the avenues to influence the aging process. There is still a need for validated techniques of estimating habitual physical activity to study the relationship between physical activity and health. Doubly labeled water studies show a decrease in the average proportion of daily energy expenditure for physical activity of about 35% at the age of 20 to 25% at the age of 90. In absolute figures, the activity-induced energy expenditure falls to one third of the initial value over the corresponding age interval. Exercise training does not seem to prevent the age-associated decline in physical activity because of compensation by a decrease in non-training physical activity, in contrast to younger age groups. The effects of the habitual activity level and of exercise on the age-related decline in muscle mass are small if present at all. There is, however, a clear-cut effect of habitual activity and exercise training on muscle function. The positive effects are reflected in muscle fiber type, capillary density, and aerobic capacity. Physical inactivity is an important determinant of disability and mortality risk. Even a recent increase in activity level can have an important effect, although the benefits are also easily lost when the activity level is again reduced.

Abstract: OBJECTIVES: Three aspects of obesity and physical activity are reviewed: whether the obese are inactive; how the activity level can be increased; and which are the effects of an increase in physical activity in combination with a reduction of energy intake. METHOD: The focus is on an objective approach that is, activity associated energy expenditure as measured with doubly labelled water. RESULTS: Activity associated energy expenditure increases with body mass index while the average physical activity level does not change. The majority of obese subjects is moderately active. An increase in the activity level of obese subjects is limited by the ability to perform exercise of higher intensity. Training programs obese subjects can cope with are until now not rewarded by weight loss. A possible loss in fat mass is compensated by a gain in fat-free mass. CONCLUSIONS: Obese subjects can only reach a significant weight loss with an energy restricted diet. Mild energy restriction will already result in very significant weight loss when one complies with the diet. An increase in physical activity is necessary to compensate for the reduction in activity induced energy expenditure and should be facilitated by the lower body mass.

Abstract: Apparatus for relating pain and activity experienced by a patient comprises: pain transducing means for allowing a patient to select any one pain level from a predetermined number of pain levels and for producing a pain level signal indicative of the selected level; activity transducing means responsive to the pain level signal for measuring a level of a parameter of a physical activity of the patient near the time corresponding to the selection of the pain level and for producing an activity parameter level signal indicative of the measured level of the parameter; and relating means responsive to the pain level signal and the activity parameter level signal for characterizing the activity of the patient corresponding to the selected level of pain to be one activity level of a predetermined number of predefined activity levels and for producing a signal indicative of the characterized level of activity and the corresponding pain level.