BackgroundThe present study compares two different weight reduction regimens both with a moderately high protein intake on body composition, serum hormone concentration and strength performance in non-competitive female athletes.MethodsFifteen normal weighted women involved in recreational resistance training and aerobic training were recruited for the study (age 28.5 ± 6.3 yr, height 167.0 ± 7.0 cm, body mass 66.3 ± 4.2 kg, body mass index 23.8 ± 1.8, mean ± SD). They were randomized into two groups. The 1 KG group (n = 8; energy deficit 1100 kcal/day) was supervised to reduce body weight by 1 kg per week and the 0.5 KG group (n = 7; energy deficit 550 kcal/day) by 0.5 kg per week, respectively. In both groups protein intake was kept at least 1.4 g/kg body weight/day and the weight reduction lasted four weeks. At the beginning of the study the energy need was calculated using food and training diaries. The same measurements were done before and after the 4-week weight reduction period including total body composition (DXA), serum hormone concentrations, jumping ability and strength measurementsResultsDuring the 4-week weight reduction period there were no changes in lean body mass and bone mass, but total body mass, fat mass and fat percentage decreased significantly in both groups. The changes were greater in the 1 KG group than in the 0.5 KG group in total body mass (p < 0.001), fat mass (p < 0.001) and fat percentage (p < 0.01). Serum testosterone concentration decreased significantly from 1.8 ± 1.0 to 1.4 ± 0.9 nmol/l (p < 0.01) in 1 KG and the change was greater in 1 KG (30%, p < 0.001) than in 0.5 KG (3%). On the other hand, SHBG increased significantly in 1 KG from 63.4 ± 17.7 to 82.4 ± 33.0 nmol/l (p < 0.05) during the weight reducing regimen. After the 4-week period there were no changes in strength performance in 0.5 KG group, however in 1 KG maximal strength in bench press decreased (p < 0.05) while endurance strength in squat and counter movement jump improved (p < 0.05)ConclusionIt is concluded that a weight reduction by 0.5 kg per week with ~1.4 g protein/kg body weight/day can be recommended to normal weighted, physically active women instead of a larger (e.g. 1 kg per week) weight reduction because the latter may lead to a catabolic state. Vertical jumping performance is improved when fat mass and body weight decrease. Thus a moderate weight reduction prior to a major event could be considered beneficial for normal built athletes in jumping events.
Estradiol fatty acid esters are potent lipophilic estrogens with antioxidant properties, transported by lipoproteins in blood. We investigated effects of oral and transdermal estradiol replacement therapy on concentrations of estradiol fatty acid esters in serum in postmenopausal women in a double-blind, randomized fashion. The first group (n = 9) received oral (2 mg/d); the second (n = 10), transdermal estradiol (patch delivering 50 microg/d); and the third group (n = 7), placebo treatment for 12 wk. After extraction of serum and separation of esterified estradiol from nonesterified estradiol, the concentration of saponified estradiol esters was measured by time-resolved fluoroimmunoassay. In the oral estradiol group, the median serum estradiol fatty acid ester concentration rose by 27%, from 77 to 98 pM (P = 0.028) but remained unchanged in the transdermal estradiol and placebo groups. The median concentrations of serum nonprotein-bound estradiol increased similarly in the oral and transdermal estradiol groups. The change in serum estradiol ester concentrations during treatment, but not that of nonesterified estradiol, correlated positively with enhanced forearm blood flow responses in vivo. These data raise the possibility that an increase in serum estradiol fatty acid esters may contribute to beneficial effects of oral estradiol treatment, compared with an equipotent dose of transdermal estradiol.
The effects of endurance training and season on the function of the anterior pituitary-thyroid axis were studied in 18 female runners and their 12 controls, and in 13 joggers and their 11 controls in Northern Finland, with a large seasonal difference in environmental factors. The serum concentrations of thyrotropin (TSH), thyroxine (T4), free thyroxine (fT4), triiodothyronine (T3), thyroxine binding globulin (TBG) and oestradiol (E2) were measured during one menstrual cycle in the light training season (autumn) and in the hard training season (spring). The responses of TSH to intravenous TRH stimulation were also measured in the luteal phase of the cycle during the hard training season. Endurance running did not affect the basal or TRH-stimulated serum TSH concentrations, while those of T4 and fT4 in runners were lowered in both seasons and that of T3 in the light training season in relation to control subjects. The serum concentrations of TBG were also significantly lower in runners than their controls in the luteal phase in both seasons. The effect of jogging on thyroid hormones was less pronounced. Serum concentrations of TSH, T4, fT4, T3 and TBG were generally slightly higher in spring than in autumn. Strenuous endurance training seems to have minor changes on the function of the thyroid gland. Depressed T4 levels in runners may rather be due to lowered TBG levels than due to direct effect of training. In spring the function of anterior pituitary-thyroid axis is more active than in autumn.The hypothalamic-pituitary-thyroid axis is sensi¬ tive to stress. During pregnancy the function of the thyroid gland increases (Burrow 1975), while in non-thyroidal illnesses, including infections, renal and hepatic diseases and starvation, the serum concentration of triiodothyronine (T3) de¬ creases and that of serum thyroxine (T4) show minor alterations (Schimmel et al. 1977).Endurance training is a hard physical stress which decreases the amount of body fat and increases demands on the energy supply, and which is partly regulated by thyroid hormones. Secretion of thyrotropin (TSH) is also under the stimulatory control of oestrogens (Labrie et al.1978), the concentrations of which, however, are decreased in female runners (Boyden et al. 1983;Ronkainen et al. 1985). Physical exercise may thus affect the function of the anterior pituitary-thy¬ roid axis of women by different mechanisms. The effects of such training on the pituitary-thyroid axis have been evaluated only in few investiga¬ tions, dealing with ballet dancers (Warren 1980) and runners (Boyden et al. 1982(Boyden et al. , 1984Marcus et al. 1985). The results in these studies have been conflicting; decreased, unchanged or increased responses of TSH and thyroid hormones to stre¬ nuous exercise have been reported.To gain information on the association of the function of the pituitary-thyroid axis and chronic, intense training in women, we measured serum concentrations of TSH, thyroid hormones, thyro¬ xine binding globulin (TBG) and oestradiol (E2) of runners, jogge...
The turnover of type III collagen, a major constituent of the myometrium and the uterine cervix, during pregnancy was evaluated by monitoring serum antigens related to the aminoterminal propeptide of type III procollagen. Their concentration increased markedly towards term in most uncomplicated pregnancies, while their size distribution throughout the pregnancy resembled that seen in the sera of normal healthy persons. In some patients, however, the level remained low, indicating interindividual variation in the release into serum and metabolism of the propeptide. There were no distinct changes during or immediately after vaginal delivery. Values exceeding the reference range for uncomplicated pregnancies were found during weeks 28-37 in patients with pre-eclampsia, essential hypertension, intrahepatic cholestasis of pregnancy or twin pregnancy. Thus, pregnancy should be taken into account when evaluating results of the serum assay for the aminopropeptide and the use of this assay as an indicator of pregnancy complications warrants further study.
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