The health benefits of resistance training for women have been well documented. However, few investigations have been reported on the immune responses to resistance training among young people. To determine the effects of resistance training on natural killer cell activity (NKCA) in young people, a study was conducted among healthy female university students.
The study was conducted with 22 healthy non athlete female university students (aged 19.8+/-1.3 years) who volunteered to participate in the study. Six women were assigned to exercise group (a) that carried out resistance training five or six times a week, another six women were assigned to exercise group (b) that carried out resistance training three or four times a week, and the remaining ten comprised, the control group (non exercise group). The exercise groups carried out resistance training for both the upper and lower parts of the body using ankle and wrist weights for 8 weeks. Blood samples were obtained at the onset of the study (before the start of any activity in the exercise groups) and at the conclusion of the training (8 weeks later) in order to determine NKCA. A physical fitness test and a muscle strength test were conducted on the subjects to assess the strength of the upper and lower parts of the body, muscular endurance, and flexibility.
The mean NKCA at the conclusion of the training showed a significant increase in exercise group (b), even though there was no significant difference in NKCA in the non exercise group or in exercise group (a) between before and after the training. An improvement in physical fitness and muscle strength was observed in exercise group (a) and exercise group (b).
This study showed that resistance training improved physical fitness, muscle strength, and NKCA in young female subjects. Regarding the effects of exercise frequency on NKCA, this study suggests that exercise carried out three of four times a week might be associated with an increase in NKCA.
[Show abstract][Hide abstract] ABSTRACT: A new method for estimating in vivo bone mineral density (BMD) and characterizing the shape of cancellous bone has been proposed using the results of ultrasonic inspection for the diagnosis of osteoporosis. The method is based on two-dimensional bone area fraction S (percent bone area between bone and bone marrow) calculated from the difference in the speed of ultrasonic wave propagation through cancellous bone. It was shown that the two-dimensional area fraction of a heel bone gives a good relationship to the BMD by DXA (dual energy x-ray absorptiometry) testing of human heel bone (calcaneus) and spine (vertebrae lumbar), as expressed by the relation, BMD (g/cm2) = 0.0167S for heel bone (r = 0.83), and BMD (g/cm2) = 0.0254S + 0.123 for the spine (r = 0.77). Shape characterization is based on the image simulation procedure employing eight random variables from a computer and the statistical results of fractal analysis for numerous cancellous bone patterns. We also demonstrate the validity of the shape characterization using autopsy specimens as a diagnostic tool for osteoporosis.
[Show abstract][Hide abstract] ABSTRACT: Muscle dysfunction and associated mobility impairment, common among the frail elderly, increase the risk of falls, fractures, and functional dependency. We sought to characterize the muscle weakness of the very old and its reversibility through strength training. Ten frail, institutionalized volunteers aged 90 +/- 1 years undertook 8 weeks of high-intensity resistance training. Initially, quadriceps strength was correlated negatively with walking time (r = -.745). Fat-free mass (r = .732) and regional muscle mass (r = .752) were correlated positively with muscle strength. Strength gains averaged 174% +/- 31% (mean +/- SEM) in the 9 subjects who completed training. Midthigh muscle area increased 9.0% +/- 4.5%. Mean tandem gait speed improved 48% after training. We conclude that high-resistance weight training leads to significant gains in muscle strength, size, and functional mobility among frail residents of nursing homes up to 96 years of age.
JAMA The Journal of the American Medical Association 07/1990; 263(22):3029-34. DOI:10.1001/jama.1990.03440220053029 · 35.29 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The involvement of cellular immunity in the burnout syndrome remains to be elucidated. We assessed three components of burnout of the Maslach Burnout Inventory: emotional exhaustion; depersonalization (DP); and personal accomplishment, as well as natural killer cell activity (NKCA) and NK cell subsets in 42 male workers. Workers with a higher DP score showed a lower NKCA and a lower proportionality of CD57+CD16+ to total lymphocytes. There were no differences in any of the health behaviors (e.g., smoking, alcohol, or obesity) between workers showing higher burnout and those showing lower burnout. A stepwise multiple regressions analysis demonstrated that NKCA was closely correlated with DP, independent of other variables, including a stress index. These results suggest that the relationship between reduced cellular immunity and DP is not due to traditional work stress or health behavioral problems. Further studies on DP as a psychosomatic disorder as well as an occupational health problem should be performed in the future.
Journal of Psychosomatic Research 07/1999; 46(6):569-78. DOI:10.1016/S0022-3999(99)00009-4 · 2.74 Impact Factor
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