ABSTRACT
[Objective] The aim of this investigation was to evaluate salivary dehydroepiandrosterone (DHEA) responses during a competitive period among female football players.<BR>[Methods] Subjects were college female football players (n=9) . Saliva and blood samples were collected at 18 : 00 (6 : 00 pm) and the profile of mood state (POMS) was recorded during a period of normal training (Pre), 3 days of competition (Competition), and a recovery period (Post) . Levels of salivary DHEA, cortisol, and serum creatin kinase (CK), urea nitorogen (UN), were determined.<BR>[Results] The levels of salivary DHEA significantly increased during competition (2 nd days) compared with Pre (p<0.05), and significantly decreased after competition compared with Pre (p<0.05) . The levels of salivary cortisol significantly increased during the competition (2 nd and 3 rd days) compared with Pre (p<0.05) . Whereas it decreased after competition compared with Pre. The levels of serum CK significantly increased during the competition (2 nd days) compared with Pre (p<0.05) . The levels of serum UN did not change during the study. The fatigue score of POMS significantly increased during competition (2 nd days) compared with Pre (p<0.05) .<BR>[Conclusion] These data suggest that DHEA could be a useful endocrinological indicator for evaluating training status in female athletes.
ABSTRACT
The purpose of this study was to investigate differences between underwater and land-based exercise in leg muscle activity. Nine healthy males (mean age : 21.7±0.5 years, mean height : 173.4±2.2 cm) had electrodes placed on their left leg muscles (Tibialis Anterior ; TA, Medial Gastrocnemius ; MG, Soleus ; SOL, Rectus Femoris ; RF, and Biceps Femoris ; BF), and their muscle activity was measured during various exercises. The subjects performed six types of exercise such as the forward walk, backward walk, squat, calf raise, leg range, and one leg wave, both in the water (waist level) and on land. These exercises were categorized as 3 types of leg movement according to direction ; horizontal, vertical, and mixed movement.<BR>In the forward walk and backward walk, categorized as horizontal movements, the integrated electromyogram (IEMG) significantly increased during underwater exercise compared with on land. In the squat, as a vertical movement, the IEMG showed a similar change under both conditions. In the calf raise, as a vertical movement, and leg range and one leg wave, as mixed movements, the IEMG significantly decreased during underwater exercise compared with on land. These results suggest that leg muscle activity during underwater exercise is different based on the movement direction of the legs. In a word, it was apparent that movement in a horizontal direction underwater provides greater activity for leg muscles than on land; but movement in a vertical and/or mixed direction underwater provides less activity for leg muscles than on land. In prescribing an exercise program, it may be helpful to understand the differences between underwater and land-based exercise in leg muscle activity.
ABSTRACT
Infection is the major cause of health impairment in elderly persons. Immune function declines with age. In order to keep the elderly in good health, it is necessary to control the age-associated decline of their immune function. Components of a non-specific immune system arc neutrophils, macrophages and NK cells. A specific immune system is composed of T lymphocytes and B lymphocytes. T lymphocytes differentiate in the thymus. Age-associated atrophy of the thymus causes a decline in T lymphocyte function. It is essential in aging of the immune system. B lymphocytes produce immunoglobulin to act as antibodies. With aging, abnormal antibodies such as autoantibodies and monoclonal immunoglobulin increase, and the number of normal antibodies compared to foreign antigens decrease. Exercise influences the autonomic nervous system, hypothalamo-hypophyseal system, and immune system. Moderate exercise enhances immune function, and severe exercise causes immune function decline. Immune function declines after a severe single bout of exercise, and an “open window” of infections occurs. Appropriate exercise training may improve immune function. Recently, it was shown that exercise training for one year increased the contents of secretory immunoglobulin A in saliva in elderly persons. This result suggests that long-term exercise training improves immune function in elderly persons.
ABSTRACT
The purpose of the present study was to investigate the effects of long-term exercise training on immune function in elderly individuals. This study was conducted on 27 sedentary subjects including 7 males and 20 females aged 66.1±4.2 yrs. (range of 60 to 77 yrs.) who participated in a 12-month exercise program. The subjects attended the exercise program 4.4 ± 1.7 times per month. Peripheral blood samples were taken prior to, and at 5 and 12 months during the exercise training program. Each lymphocyte subset (natural killer: NE, T, cytotoxic T: Tc, helper T: Th, memory-Th and NKT) count in the samples was measured using flow cytometry. Results indicated that NE and Tc cell counts were not significantly altered. Whereas, T and Th cell counts were significantly elevated after 12 months, and memory-Th and NET cell counts were significantly elevated after 5 and 12 months of exercise training. These results suggest that long-term exercise training may be a stimu lus to increase and or maintain immune function in elderly individuals.
