Izvorni znanstveni članak
Health impact of training intensity in older individuals
Katarina T. Borer
; Division of Kinesiology, University of Michigan, Ann Arbor, USA
Germaine Cornelissen
; Chronobiology Center, University of Minnesota, Minneapolis, USA
Franz Halberg
; Chronobiology Center, University of Minnesota, Minneapolis, USA
Courtney Hughes
; Division of Kinesiology, University of Michigan, Ann Arbor, USA
Sažetak
As we age, our capacity for sustained and intense physical exertion declines. This partly represents a decline in cardio-respiratiry capacity. The aim of this study was to examine the extent to which a simple prototypic form of physical activity, walking, can improve components of cardio-respiratory function in aging individuals. Postmenopausaul women were selected for study because of their cardio-respiratory function, and their increased risk of CHD following estradiol decline. Walking was selected because it is the principal physical means of human locomotion and dynamically engages large muscle groups. It also is universally accessible without the necessity for specialized equipment or facilities. Subjects were 42 generally healthy overweight to moderately obese postmenopausal women aged 58. Training consisted of walking 4.83 km/day five days a week for 15 weeks at an assigned intensity. Before the start, and after 15 weeks of training, the following measurements were taken: body mass and stature, body mass index, skinfolds and circumferences were measured at standardized sites for calculation of body fat according to Jackson, Pollock and Ward, ventilatory threshold, heart rate and blood pressure. Changes in HR and BP and their variabilities were assessed from HR and BP recordings collected during seven consecutive days with the TM2421 ambulatory HR-BP monitors (A & D Company, Tokyo, Japan).
This study permits several conclusions regarding the effectiveness of walking as a means of cardio-resporatory conditioning for postmenopausal women. The overall conclusion is that 15 weeks of walking are sufficient for an increase in aerobic capacity, and that the magnitude of the effect will be, in agreement with Karvonen's observations, proportional to training intensity.
The second conclusion is that, under the conditions of this study, training intensity has pleiotropic effects on individual cardiorespiratory variables and their components. It significantly stimulated increases in aerobic capacity, but exerted insignificant lowering tendency on HR and BP parameters. Within each cardio-respiratory variable, only some components showed the effects of training intensity, while the others were unaffected. Thus, training intensity tended to decrease BPsys, BPdia, and HR MESORs, and usually only one measure of their variability (BPsys double amplitude, and BPdia and HR SDs).
Ključne riječi
adults, training intensity, health
Hrčak ID:
330931
URI
Datum izdavanja:
20.12.2004.
Posjeta: 23 *