Search results for "testosterone"
showing 10 items of 420 documents
Serum Sex Hormone–Binding Globulin and Cortisol Concentrations are Associated With Overreaching During Strenuous Military Training
2010
The purpose was (a) to study the effect of an 8-week Finnish military basic training period (BT) on physical fitness, body composition, mood state, and serum biochemical parameters among new conscripts; (b) to determine the incidence of overreaching (OR); and (c) to evaluate whether initial levels or training responses differ between OR and noOR subjects. Fifty-seven males (19.7 ± 0.3 years) were evaluated before and during BT. Overreaching subjects had to fulfill 3 of 5 criteria: decreased aerobic physical fitness (VO2max), increased rating of perceived exertion (RPE) in 45-minute submaximal test at 70% of VO2max or sick absence from these tests, increased somatic or emotional symptoms of …
Effect of time-of-day-specific strength training on serum hormone concentrations and isometric strength in men.
2007
A time-of-day influence on the neuromuscular response to strength training has been previously reported. However, no scientific study has examined the influence of the time of day when strength training is performed on hormonal adaptations. Therefore, the primary purpose of this study was to examine the effects of time-of-day-specific strength training on resting serum concentrations and diurnal patterns of testosterone (T) and cortisol (CORT) as well as maximum isometric strength of knee extensors. Thirty eight diurnally active healthy, previously untrained men (age 20-45 yrs) underwent a ten-week preparatory strength training period when sessions were conducted between 17:00-19:00 h. Ther…
Acute elevations in serum hormones are attenuated after chronic training with traditional isoinertial but not accentuated eccentric loads in strength…
2017
It has been proposed that the maintenance of acute hormonal responses reveal an efficacy of a training stimulus to evoke ongoing increases in strength and muscle mass. We previously observed that maximum strength continued to improve throughout a 10‐week period in an accentuated eccentric loading group (AEL) but not a traditional isoinertial loading (ISO) group. Therefore, this study investigated whether the magnitude of acute hormonal responses was greater (i.e., maintained) in AEL compared to ISO at the end of the training period. Subjects in AEL (eccentric load = concentric load + 40%) and ISO performed experimental loading tests (three sets of 10 repetitions in the leg press and knee ex…
Can Cold Water Immersion Enhance Recovery in Elite Olympic Weightlifters? An Individualized Perspective.
2017
We investigated whether cold water immersion (CWI) after intensive training sessions can enhance recovery in elite Olympic weightlifters, taking into account each athlete's individual response pattern. The entire German male Olympic weightlifting national team participated in the study (n = 7), ensuring collection of data from elite athletes only. Using a randomized cross-over design, the athletes went through 2 high-intensity training microcycles consisting of 5 training sessions that were either followed by a CWI or passive recovery. Barbell speed in a snatch pull movement, blood parameters, and subjective ratings of general fatigue and recovery were assessed throughout the study. Physica…
Resistance exercise-induced hormonal responses in men, women, and pubescent boys.
2002
PULLINEN, T., A. MERO, P. HUTTUNEN, A. PAKARINEN, and P. V. KOMI. Resistance exercise-induced hormonal responses in men, women, and pubescent boys. Med. Sci. Sports Exerc., Vol. 34, No. 5, pp. 806 – 813, 2002. Purpose: This study was designed to investigate the acute plasma catecholamine (CA) response to resistance exercise and its association with serum testosterone (TES), cortisol (COR), and growth hormone (GH) concentration changes. Methods: Six men, six women, and six adolescent boys (14 0 yr) performed five sets of 10 knee extensions with 40% of one-repetition maximum followed by two sets performed to exhaustion. Arterialized venous blood was sampled before, during, and after the exerc…
Step vs. Two-Phase Gradual Volume Reduction Tapering Protocols in Strength Training: Effects on Neuromuscular Performance and Serum Hormone Concentra…
2020
ABSTRACT Seppanen, S and Hakkinen, K. Step vs. two-phase gradual volume reduction tapering protocols in strength training: Effects on neuromuscular performance and serum hormone concentrations. J Strength Cond Res XX(X): 000-000, 2020-This study assessed effects of 2 reduced volume tapering protocols on neuromuscular performance and serum hormone concentrations in 14 recreationally strength-trained men (21-30 years). After an 8-week strength training period subjects were divided to the step (54% volume reduction immediately) and 2-phase gradual (38% reduction for the first week and 70% for the second week) tapering groups for 2 weeks. One repetition maximum (1RM) squat, maximal isometric bi…
Differential effect of hypophysectomy and growth hormone treatment on hepatic glucuronosyltransferases in male rats: Evidence for an action at a pret…
1997
International audience; The influence of growth hormone (GH) on 4-nitrophenol, bilirubin, testosterone, androsterone and estrone glucuronidation activities was studied in fully activated male rat hepatic microsomes. Sham-operated and hypophysectomized animals were injected with two different dosages of GH, mimicking either the male or female GH secretion pattern. Half the animals received thyroxine and cortisol in concentrations chosen to compensate for the lack of thyroid hormones and glucocorticoids in hypophysectomized rats. GH induced a decrease in several glucuronidation activities: bilirubin glucuronidation in both sham-operated and cortisol/ thyroxine-treated hypophysectomized rats i…
Chernobyl exposure as stressor during pregnancy and hormone levels in adolescent offspring
2008
Background: Animal research suggests a programming effect of prenatal stress in the fetal period, resulting in disruptions in behavioural and neuromotor development. Physiological changes that mediate these effects include alterations in the hypothalamic-pituitary-adrenal axis and in testosterone levels. This human study focuses on changes related to these physiological systems after prenatal stress exposure. Methods: We examined the potential effect of prenatal stress associated with the Chernobyl disaster in an ongoing genetic epidemiological study in Finland. One birth cohort of twins (n = 121 twin pairs) was exposed in utero to maternal stress, and their saliva cortisol and testosterone…
Similar rewarding effects of testosterone in mice rated as short and long attack latency individuals.
2002
An attempt was made to confirm and extend the findings of an earlier study on the rewarding properties of testosterone in male mice using conditioned place preference (CPP). Previous results had only partially demonstrated such an effect because the reinforcement depended on environmental cues such as the colour of the compartment. High individual variability was evident, suggesting that basal levels of aggressiveness may modulate such effects. Animals were pre-screened for aggressive behaviour and allocated to short and long attack latency (SAL and LAL) categories. Five days later the CPP procedure started. This involved pre-conditioning tests, conditioning and post-conditioning tests. SAL…
Actions of sex hormones on the brain
1992
1. The brain is a target for sex steroid hormones. As a result of sex hormone actions on the brain various behavioral changes are observed in animal and man. This paper gives a brief overview over the multiple central nervous functions that are under modulatory control of sexual hormones and describes the complex sex steroid actions on the brain by giving an example for "activating" and "organizing" effects of estrogens on noradrenergic neurons in the brain of rats. 2. Estradiol-17 beta induced sex specific alterations in the turnover of noradrenaline in the preoptic area and mediobasal hypothalamus showing "female" or "male" responses. 3. Neonatal manipulations of female rat pups by testos…