ABSTRACT
The effects of 12 weeks of a low-intensity general conditioning programme on maximal instantaneous peak power (Wpeak) and maximal oxygen uptake (VO2max) were examined in 20 elderly women. After medical, familiarisation, and ethical procedures, the subjects were randomly divided into either a training and or a control group. The training group [n = 11; mean (SD) age 63.0 (3.1) years] agreed to take part in a 12-week training programme at an exercise intensity kept under 60% of the heart rate reserve for about 60 min, 3 times a week. The control group [n = 9; mean (SD) age 63.5 (3.3) years] did not perform any particular physical training. Before and after the training period, all participants underwent anthropometric measures and a maximal cycling test to exhaustion to measure their VO2max. In addition, Wpeak was determined 1 week later by the subjects performing a vertical jump from a squatting position on a force platform. Following training, neither the anthropometric characteristics nor the VO2max changed in either of the groups. In contrast, Wpeak increased significantly (P < 0.001) in the training group, but did not change in the control group. This result could be interpreted as the result of an improved level of neuromuscular activation. Furthermore, it shows that although muscle power declines with age at a faster rate than does aerobic power, its sensitivity to training seems to be higher than that of the aerobic system.
Subject(s)
Exercise/physiology , Heart Rate/physiology , Maximal Voluntary Ventilation/physiology , Muscle Contraction/physiology , Age Factors , Aged , Body Mass Index , Body Weight/physiology , Female , Humans , Middle Aged , Oxygen Consumption/physiologyABSTRACT
The present study aimed at analysing the age-related decline in maximal muscle power (W) in 52 sedentary healthy women aged between 50 and 75 years to determine whether force or velocity is the major determinant. Maximal muscle power was estimated from two types of vertical jumps, squatting (SJ) and countermovement (CmJ), performed on a force platform. It was obtained by measuring the vertical force (F(opt)) applied to the body centre of gravity and calculating the corresponding vertical velocity (v(opt)). An age-related decline in absolute W was statistically significant in all the conditions examined and in both peak W and average power (W) values. The decrease in v(opt) was also statistically significant. Also F(opt) declined but this reduction was not statistically significant with the exception of the average value in CmJ. Not surprisingly the highest W were obtained in CmJ, and the difference in power production between the two types of jump showed an age-related decrement only in W. The main finding of the study was the demonstration that v(opt) was the critical determinant of the age-related decline in W in healthy elderly women.
Subject(s)
Aging/physiology , Muscle Contraction/physiology , Muscle, Skeletal/physiology , Aged , Biophysical Phenomena , Biophysics , Female , Humans , Middle AgedABSTRACT
The ability in maintaining body balance of 6-, 8-, and 10-year-old children performing three balance tests on a force platform was studied. Thirty adult subjects served as a reference group. The mean radius (MR) of the posturogram and the mean speed (MS) of the center of foot pressure (COP) were used as the measuring parameters. Data were analyzed using two-way ANOVA, the Sheffe test and the Student "t" test with a .05 level of significance. A decrease with age in both mean radius and mean speed, indicating an increase in balance ability, was noted. A significant age main effect was found on all tests while significant gender main effect occurred only on the Tandem test. No significant age/sex interaction was found. Significant differences between the 10-year-old and adult groups occurred only in the more difficult balance tests.
