Healthy Young Men Research Articles

Effects of testosterone enanthate on aggression, risk-taking, competition, mood, and other cognitive domains during 28 days of severe energy deprivation

RationaleBehavioral effects of testosterone depend on dose, acute versus sustained formulation, duration of administration, personality, genetics, and endogenous levels of testosterone. There are also considerable differences between effects of endogenous and exogenous testosterone.ObjectivesThis study was the secondary behavioral arm of a registered clinical trial designed to determine if testosterone protects against loss of lean body mass and lower-body muscle function induced by a severe energy deficit typical of sustained military operations.MethodsBehavioral effects of repeated doses of testosterone on healthy young men whose testosterone was reduced by severe energy deficit were examined. This was a double-blind, placebo-controlled, between-group study. Effects of four weekly intramuscular injections of testosterone enanthate (200 mg/week, N = 24) or matching placebo (N = 26) were evaluated. Determination of sample size was based on changes in lean body mass. Tasks assessing aggression, risk-taking, competition, social cognition, vigilance, memory, executive function, and mood were repeatedly administered.ResultsDuring a period of artificially induced, low testosterone levels, consistent behavioral effects of administration of exogenous testosterone were not observed.ConclusionsExogeneous testosterone enanthate (200 mg/week) during severe energy restriction did not reliably alter the measures of cognition. Study limitations include the relatively small sample size compared to many studies of acute testosterone administration. The findings are specific to healthy males experiencing severe energy deficit and should not be generalized to effects of other doses, formulations, or acute administration of endogenous testosterone or studies conducted with larger samples using tests of cognitive function designed to detect specific effects of testosterone.

Muscle Fiber Conduction Velocity During Electrically Stimulated Contraction at Various Joint Angles, During Joint Movements, and During Voluntary Contractions.

Muscle fiber conduction velocity (MFCV) can be affected by muscle fiber geometry at different joint angles and during joint movements. This study aimed to investigate MFCV during electrically evoked contraction at different joint angles, during joint movements, and during voluntary contractions. Sixteen healthy young men participated. A stimulation electrode was attached on the innervation zone of the vastus lateralis, and a linear electrode array was attached on the vastus lateralis. Under a static condition, electrically evoked electromyography signals were recorded at knee joint angles set every 15° between 0° and 105°. Under a passive movement condition, signals were recorded during knee extension and flexion passively. Under a voluntary contraction condition, signals were recorded while performing 30% or 60% of maximum voluntary contraction. MFCV was calculated using cross-correlation coefficients. Under the static condition, there were no differences in MFCV among various joint angles. Under the passive movement condition, MFCV was significantly greater during high velocity or shortening. Under the voluntary contraction condition, MFCV was significantly greater during high-intensity voluntary contraction and with a shortened muscle length. Joint angles do not influence MFCV markedly during relaxation, but it is possible to overestimate MFCV during movement or voluntary contraction.

Effects of Bolus Types and Swallowing Maneuvers on Laryngeal Elevation: Analysis of Healthy Young Adult Men and Healthy Older Men.

Peak velocity, distance, and time of laryngeal elevation during swallowing were measured with a laryngeal motion measurement system in eight healthy young adult men in their 20 and 30s (33.0 ± 4.3years) and ten healthy older men in their 60 and 70s (74.0 ± 3.9years). The participants performed swallowing five times each for a total of eight conditions: two bolus types (saliva and water) and four swallowing methods (normal swallow, effortful swallow, super-supraglottic swallow, and Mendelsohn maneuver). When the bolus type was saliva, peak velocity and distance increased more for swallowing maneuvers (effortful swallow, super-supraglottic swallow, and Mendelsohn maneuver) than for normal swallow. On the other hand, when the bolus type was water, there was no difference in peak velocity or distance between normal swallow and swallowing maneuvers. In healthy older men, distance was greater with Mendelsohn maneuver than with normal swallow, and peak velocity was increased with swallowing maneuvers than with normal swallow. Healthy young adult men had increased peak velocity and distance with water rather than saliva. The increase in peak velocity and distance obtained by swallowing maneuvers was influenced by age and bolus, suggesting that the subjects and conditions used are important in terms of promoting safer oral intake.

Three-week sprint interval training (SIT) reduces cell-free DNA and low-frequency fatigue but does not induce VO2max improvement in older men.

This study aimed to investigate the impact of sprint interval training (SIT) on both the acute and 3-week modulations of cell-free DNA (cfDNA), as well as its association with neuromuscular fatigue and physical performance in healthy young and old men. Ten young (20-25year old) and nine elderly (63-72year old) healthy men performed nine SIT sessions consisting of 4-to-6-all-out cycling repetitions of 30s interspaced with 4-min rest intervals. We compared the maximal voluntary contractions torque, central activation ratio, low-frequency fatigue (LFF), and cfDNA concentrations between the groups before, immediately after, 1h after, and 24h after the first and ninth SIT sessions. The plasma cfDNA levels were increased post-exercise (from 1.4 ± 0.258 to 1.91 ± 0.278ng/ml (P < 0.01) on a log10 scale), without significant differences between the groups. However, older individuals showed a slight decrease in the baseline cfDNA values, from 1.39 ± 0.176 to 1.29 ± 0.085ng/ml on a log10 scale, after 3weeks (P = 0.043). Importantly, the elevation of the post-exercise cfDNA values was correlated with an increase in LFF in both groups. Three weeks of SIT induced an improvement in the recovery of LFF (main session effect, P = 0.0029); however, only the young group showed an increase in aerobic capacity (VO2max) (from 40.8 ± 6.74 to 43.0 ± 5.80ml/kg/min, P = 0.0039). Three weeks of SIT diminished the baseline cfDNA values in the old group, together with an improvement in the recovery of LFF. However, VO2max was increased only in the young group.

In vivo marker of brainstem myelin is associated to quantitative sleep parameters in healthy young men

The regional integrity of brain subcortical structures has been implicated in sleep–wake regulation, however, their associations with sleep parameters remain largely unexplored. Here, we assessed association between quantitative Magnetic Resonance Imaging (qMRI)-derived marker of the myelin content of the brainstem and the variability in the sleep electrophysiology in a large sample of 18-to-31 years healthy young men (N = 321; ~ 22 years). Separate Generalized Additive Model for Location, Scale and Shape (GAMLSS) revealed that sleep onset latency and slow wave energy were significantly associated with MTsat estimates in the brainstem (pcorrected ≤ 0.03), with overall higher MTsat value associated with values reflecting better sleep quality. The association changed with age, however (MTsat-by-age interaction—pcorrected ≤ 0.03), with higher MTsat value linked to better values in the two sleep metrics in the younger individuals of our sample aged ~ 18 to 20 years. Similar associations were detected across different parts of the brainstem (pcorrected ≤ 0.03), suggesting that the overall maturation and integrity of the brainstem was associated with both sleep metrics. Our results suggest that myelination of the brainstem nuclei essential to regulation of sleep is associated with inter-individual differences in sleep characteristics during early adulthood. They may have implications for sleep disorders or neurological diseases related to myelin.

Quantitative study of 3.0T MRI on the thickness of knee joint cartilage in healthy young people

To explore 3.0T MRI accurate measurement of knee cartilage thickness in healthy youth provides reliable anatomical parameters for quantitative diagnosis of osteoarthritis and accurate osteotomy of joint replacement. From January 2013 to December 2013, 30 healthy young volunteers including 14 males and 16 females with an average age of (25.8±2.4) years old ranging from 22 to 33 years were recruited in Changchun, Jilin Province, and a 3.0T MRI scan was performed on the bilateral knee joints of each volunteer. The cartilage thickness was measured on the lateral femoral condyle (LFC), medial femoral condyle (MFC), lateral tibial plateau (LTP) and medial tibial plateau (MTP). In four regions of the knee joint:LFC, MFC, LTP and MTP, whether young men or women, there was no significant difference in cartilage thickness between the left and right knee joints (P>0.05). There were significant differences in knee cartilage thickness between healthy young men and women (P<0.05). In the same sex group, LFC cartilage thickness was thinner in the middle, thicker in front and rear;MFC cartilage thickness was the thinnest in front and gradually thickening from the front to the rear; LTP cartilage thickness was thickest in the middle, second in the rear and thinnest in the front;MTP cartilage thickness was the thinnest in the front, was relatively uniform in the middle and rear and thicker than that in the front. In Northeast China, among healthy adults aged 22 to 33, gender difference may be an important factor in the difference of cartilage thickness in various regions of the knee joint. Regardless of whether male or female healthy young people, the cartilage thickness of the entire knee joint is unevenly distributed, but there is no significant difference in cartilage thickness in the same area between the left and right knee joints.

Salivary concentrations of secretory leukocyte protease inhibitor and matrix metallopeptidase-9 following a single bout of exercise are associated with intensity and hydration status.

To investigate the effects of exercise on salivary concentrations of inflammatory markers by analyzing a panel of 25 inflammatory markers in subjects who had participated in bicycle ergometer tests varying in workload and hydration status. Fifteen healthy young men (20-35 years) had performed 4 different exercise protocols of 1 hour duration in a randomly assigned cross-over design, preceded by a rest protocol. Individual workloads depended on participant's pre-assessed individual maximum workload (Wmax): rest (protocol 1), 70% Wmax in hydrated (protocol 2) and dehydrated (protocol 3) state, 50% Wmax (protocol 4) and intermittent 85%/55% Wmax in 2 min blocks (protocol 5). Saliva samples were collected before (T0) and immediately after exercise (T1), and at several time points after exercise (2 hours (T3), 3 hours (T4), 6 hours (T5) and 24 hours (T6)). Secretory Leukocyte Protease Inhibitor (SLPI), Matrix Metallopeptidase-9 (MMP-9) and lactoferrin was analyzed using a commercial ELISA kit, a panel of 22 cytokines and chemokines were analyzed using a commercial multiplex immunoassay. Data was analyzed using a multilevel mixed linear model, with multiple test correction. Among a panel of 25 inflammatory markers, SLPI concentrations were significantly elevated immediately after exercise in all protocols compared to rest and higher concentrations reflected the intensity of exercise and hydration status. MMP-9 showed a significant increase in the 70% Wmax dehydrated, 50% Wmax and intermittent protocols. Salivary concentrations of SLPI and MMP-9 seem associated with exercise intensity and hydration status and may offer non-invasive biomarkers to study (local) inflammatory responses to different exercise intensities in human studies.

Does an outdoor virtual environment projected in a head-mounted display affect balance in healthy young adults?

BackgroundVirtual reality head-mounted display (VR-HMD) is increasingly used for balance evaluation and rehabilitation. However, more studies must be conducted on virtual environments (VE) effects. This study aimed to assess the impact of an outdoor VE projected in a high-quality VR-HMD and of the VR-HMD mass on postural stability, postural control and leaning. MethodsThis study involved ten healthy young men who performed five 30-s stabilometric trials. Four experimental conditions were randomly performed: eyes open (EO) or eyes closed (EC), with (VR) or without (No VR) VR-HMD. Postural stability (antero-posterior (AP) and medio-lateral (ML) ranges of the center of pressure (CoP), 90% confidence ellipse area), postural control (CoP velocity (global, AP and ML)) and standard deviation of the CoP mean position), and postural leaning (AP/ML CoP mean position) were assessed. The comparisons between EO VR and EO No VR were used to analyze the VE effects and comparisons between EC VR and EC No VR for the VR-HMD mass effects. ResultsSpatiotemporal parameters that characterised postural stability and postural control, except ML velocity (p > 0.05), were significantly influenced by the simulated VE with higher values in EO VR than EO No VR (p < 0.05), but not by the VR-HMD mass. The mean position of the CoP showed no significant differences between conditions. SignificancePostural stability and postural control modification due to the VE used in this study revealed that this VE could be interesting for VR-HMD rehabilitation and assessment. VR-HMD is not a factor to be considered for stabilometric analysis.

Diurnal differences in urine flow in healthy young men in a light-controlled environment: a randomized crossover design

BackgroundOlder men often experience nocturnal urination difficulties, reflected by diurnal differences in maximum urine flow (Qmax). Since lower urinary tract symptoms and pathological comorbidities are frequent in older men, it remains unclear whether this diurnal variation is a physiological or pathological phenomenon. Our aim was to quantify the diurnal variability of Qmax in healthy young participants under varying daylight conditions in a stable environment to discern potential underlying causes of nocturnal urination difficulties.MethodsTwenty-one healthy young men were recruited in a 4-day study utilizing daytime (08:00–18:00) exposure with two light conditions in randomized order: dim (< 50 lx) or bright (~2500 lx). Day 1 was for acclimation, and urine flow was assessed from day 2. The participants urinated ad libitum during day 2 and then at fixed 3–4-h intervals thereafter (days 3–4). Regular urination Qmax at late night (04:00) on day 4 was compared with the nearest voided volume during daytime of day 3 (mDay).ResultsMorning Qmax scores (after bed—11:00) on day 2 were significantly lower than evening (17:00—before pre-sleep) in bright conditions and those of daytime (11:00–17:00), evening (17:00—before pre-sleep), and pre-sleep in dim conditions. Pre-sleep Qmax during the ad libitum period was significantly higher in dim than bright conditions. Late-night Qmax values (04:00) on day 4 were significantly lower than Qmax scores of mDay on day 3 in both light conditions.ConclusionsHealthy young men had a clear diurnal Qmax difference that decreased during late night and morning. In addition, the pre-sleep Qmax values in dim daylight were significantly higher than in bright daylight. Taken together, we conclude that late-night and morning decreases in Qmax are an instinctive physiological phenomenon in humans, and the diurnal difference of Qmax can be influenced by daylight conditions.

In otherwise healthy young men, Trabecular Bone Score (TBS) is significantly lower in case of insulin resistance: an analysis of the SIBLOS study

In otherwise healthy young men, Trabecular Bone Score (TBS) is significantly lower in case of insulin resistance: an analysis of the SIBLOS study

Demographic characteristics, laboratory features and complications in 346 cases of brucellosis: A retrospective study from Qatar

ObjectivesTo study the epidemiology and laboratory findings and outcomes of human brucellosis in the state of Qatar. MethodsA retrospective study involving adult patients with a definitive diagnosis of brucellosis was conducted. ResultsOf the 346 patients 299 were males. The mean age was 39.62 years. 120 patients had history of drinking raw milk and 116 had a history of contact with animals. Fever (89.9%) and myalgia (56.6%) were the most common presenting symptoms observed. Raised C-reactive protein level was the most frequent laboratory finding noted. Alanine aminotransferase and aspartate aminotransferase levels were raised to three times the normal in 39.6% and 37% of patients, respectively. Blood culture was positive in 72.8% whereas Brucella immunoglobulin G antibody and immunoglobulin M antibody titer was positive in 72.5% and 73.1% patients, respectively. Approximately 21.4% had focal involvement and osteoarticular (11.6%) involvement was the most frequently observed focal form. Doxycycline with rifampicin or gentamicin was the common regimen received. Relapse was seen in 7.2% patients. ConclusionHuman brucellosis continues to be a serious health issue in Qatar predominantly affecting healthy young adult men resulting in significant morbidity. Preventive measures and community awareness particularly among high-risk groups will help in decreasing the prevalence of the disease and its aftereffects.

Prediction of maximal oxygen uptake based on anthropometric indices in Iranian male adults.

Assessment of maximal oxygen consumption is important in both general community and occupational settings. Validity and reliability tests are needed to indicate the functionality of the cardiopulmonary system. This study aimed to establish a maximal oxygen consumption (VO2max) prediction model using anthropometric and demographic variables for young adults in Iran. This cross-sectional study was conducted on 64 healthy young men aged 19-29 years. Oxygen consumption was measured directly and the prediction models to estimate VO2max were determined by multiple linear regression. The accuracy of the prediction models was considered using regression coefficient (R), coefficient of determination (R2), and standard error of estimate (SEE). The average VO2max was 44.02±4.31 ml/kg/min. Significant correlations were found between the measured VO2max and the anthropometric and demographic variables (r = 0.16-0.86, P < 0.05). Three significant regression models with acceptable accuracy were developed (R2 = 0.67-0.71, SEE = 3.19-3.21). The predictive models consisted of 3-5 variables as significant predictors of VO2max and had acceptable accuracy for Iranian young adults. The proposed models are a simple and valid tool that can be used to estimate the VO2max in the field and in laboratory settings.

The Effects of Bovine Colostrum on the Stress-Hyperglycemia Ratio and the Triglyceride-Glucose Index in Exercise-Trained Healthy Subjects: A Double-Blind, Placebo-Controlled Clinical Study

Bovine colostrum (BC) is a natural substance that has been shown of benefits for exercising, and reducing the blood glucose levels in type 2 diabetes. Stress hyperglycemia is a brief rise in blood glucose levels caused by physiological stress. This placebo-controlled clinical study aimed to investigate the effects of BC on stress hyperglycemia and the triglyceride-glucose index in healthy subjects who trained in resistance exercise. This research was carried out at Al-Kut University College from April 30th to November 30th, 2022. Fifty healthy young men were randomly assigned: Group I (n = 24) received a placebo, whereas Group II (n = 26) received a 500mg single oral dosage of BC nutraceutical pill. During the treatment period, both groups of volunteers engaged in resistance exercise training. Body mass index (BMI), waist circumference (WC), stress glucose ratio (SGR), triglyceride-glucose index (TyGI), and rate pressure product (as a hemodynamic response) were all measured at the start and end of the eight-week study.‎ Stress blood glucose levels were considerably higher in Group II following resistance training (89.0±6.5 vs 102.1±11.5mg/dL, p&lt;0.001), whereas stress HbA1c% did not alter (4.70±0.25 vs 4.66±0.29, p=0.608). Bovine colostrum significantly increases the SGR from 1.01±0.03 to 1.18±0.13, p&lt;0.001. The TyGI at the stress glucose level was increased by 2.7%. We conclude that bovine colostrum significantly elevates the stress hyperglycemic ratio without inducing significant changes in the TyGI following exercise. This impact is accompanied by a stabilizing hemodynamic response.&#x0D; &#x0D;

Load-Time and Load-Speed Relationship in the Resisted Sled Sprint Exercise: What Independent Variable Most Accurately Determines the Relative Load?

Jiménez-Lozano, M, Yáñez-García, JM, Mora-Custodio, R, Valle-Salguero, A, Díez-Fernández, DM, Franco-Márquez, F, González-Badillo, JJ, and Rodríguez-Rosell, D. Load-time and load-speed relationship in the resisted sled sprint exercise: what independent variable most accurately determines the relative load? J Strength Cond Res 37(11): 2167-2177, 2023-The aims of this study were to analyze the load-speed and load-time relationships in the resisted sled sprint exercise using different variables as relative load and to estimate the decrement of speed sprint and the increase of sprint time across different loads. Thirty young healthy men performed a progressive loading test in the countermovement jump (CMJ) exercise to determinate the load that elicited a 2 m·s-1 peak velocity (PV2-load) and in the full squat exercise to obtain the 1 repetition maximum (1RM) value and the load that elicited a 1 m·s-1 mean velocity (V1-load). In addition, subjects performed a progressive loading test in the resisted sled sprint exercise, whereas time and instantaneous speed at 10 (T10 and V10) and 20 m (T20 and V20) were measured. The independent variables used were body mass (BM), 1RM and V1-load in the squat exercise, the PV2-Load in the loaded CMJ exercise, 1RM + BM, V1-Load + BM, and PV2-Load + BM. To analyze whether relationships were dependent on individual performance obtained in unloaded sprint, the total sample was divided into 3 subgroups: high performance (T20 < 3.00 s), medium performance (T20:3.00-3.12 s), and low performance (T20 > 3.12 seconds) groups. The independent variables showing the highest relationships with time and speed in 10 and 20 m were %BM, %BM + V1-load, and %BM + PV2-load. Statistically significant differences between performance groups in %DSS (decrease of sprint speed) and %IST (increase sprint time) in 20 m were found when %BM was used as relative load, whereas there were no significant differences between groups for %BM + PV2-load or %BM + V1-load. In conclusion, the use of %BM + PV2-load and %BM + V1-load should be considered as variables for monitoring the relative load in the resisted sled sprint exercise.

The relationship between anthropometric and metabolic risk factors and testicular function in healthy young men.

This study investigated the relationship of anthropometric and metabolic risk factors with seminal and sex steroidal hormone parameters in a screened population of healthy males. The participants were healthy young men without chronic or congenital diseases. The body composition parameters that we investigated were measured weight, height, and waist circumference (WC), as well as bioelectrical impedance analysis. Semen samples were analyzed for semen volume, sperm concentration, sperm motility and morphology, seminal pH, and liquefaction time. Biochemistry analysis, including glucose and lipid metabolism parameters, was conducted on fasting blood samples. Testicular volume was calculated separately for each testis using ultrasonography. Body mass index exhibited an inverse association with total sperm count. WC showed negative correlations with numerous seminal parameters, including sperm concentration, total sperm count, sperm morphology, and follicle-stimulating hormone levels. The basal metabolic rate was associated with seminal pH, liquefaction time, and sperm motility. WC, fat mass percentage, and triglyceride levels exhibited negative correlations with sex hormone binding globulin. The measures of glucose metabolism were associated with a greater number of seminal parameters than the measures of cholesterol metabolism. C-reactive protein levels were inversely associated with sperm concentration and total sperm count. Anthropometric and metabolic risk factors were found to predict semen quality and alterations in sex steroidal hormone levels.

Effects of a 20-Week High-Intensity Strength Training Program on Muscle Strength Gain and Cardiac Adaptation in Untrained Men: Preliminary Results of a Prospective Longitudinal Study.

As strength sports gain popularity, there is a growing need to explore the impact of sustained strength training on cardiac biventricular structure and function, an area that has received less attention compared to the well-established physiological cardiac adaptation to endurance training. This study aims to implement a 20-week high-intensity strength training program to enhance maximal muscle strength and evaluate its impact on cardiac biventricular adaptation in healthy, untrained men. A total of 27 healthy and untrained young men (mean age 22.8, SD 3.2 years) participated in a strength training program designed to increase muscle strength. The training program involved concentric, eccentric, and isometric exercise phases, conducted over a consecutive 20-week time frame with a frequency of 3 weekly training sessions. Participants were evaluated before and after 12 and 20 weeks of training through body composition analysis (bioelectrical impedance), a 12-lead resting electrocardiogram, 3D transthoracic echocardiography, cardiopulmonary exercise testing, and muscle isokinetic dynamometry. The progression of strength training loads was guided by 1-repetition maximum (RM) testing during the training program. Of the initial cohort, 22 participants completed the study protocol. No injuries were reported. The BMI (mean 69.8, SD 10.8 kg/m² vs mean 72, SD 11 kg/m²; P=.72) and the fat mass (mean 15.3%, SD 7.5% vs mean 16.5%, SD 7%; P=.87) remained unchanged after training. The strength training program led to significant gains in 1-RM exercise testing as early as 4 weeks into training for leg extension (mean 69.6, SD 17.7 kg vs mean 96.5, SD 31 kg; P<.001), leg curl (mean 43.2, SD 9.7 kg vs mean 52.8, SD 13.4 kg; P<.001), inclined press (mean 174.1, SD 41.1 kg vs mean 229.2, SD 50.4 kg; P<.001), butterfly (mean 26.3, SD 6.2 kg vs mean 32.5, SD 6.6 kg; P<.001), and curl biceps on desk (mean 22.9, SD 5.2 kg vs mean 29.6, SD 5.2 kg; P<.001). After 20 weeks, the 1-RM leg curl, bench press, pullover, butterfly, leg extension, curl biceps on desk, and inclined press showed significant mean percentage gains of +40%, +41.1%, +50.3%, +63.5%, +80.1%, +105%, and +106%, respectively (P<.001). Additionally, the isokinetic evaluation confirmed increases in maximal strength for the biceps (+9.2 Nm), triceps (+11.6 Nm), quadriceps (+46.8 Nm), and hamstrings (+25.3 Nm). In this paper, only the training and muscular aspects are presented; the cardiac analysis will be addressed separately. This study demonstrated that a short-term high-intensity strength training program was successful in achieving significant gains in muscle strength among previously untrained young men. We intend to use this protocol to gain a better understanding of the impact of high-intensity strength training on cardiac physiological remodeling, thereby providing new insights into the cardiac global response in strength athletes. ClinicalTrials.gov NCT04187170; https://clinicaltrials.gov/study/NCT04187170.

Impact of SARS-CoV-2 and Other Upper Respiratory Tract Viral Infections on Reproductive Parameters in Young Healthy Men with Mild Symptoms of Disease

Data regarding excretion of SARS-CoV-2 in semen are inconclusive and counseling regarding risk of sexual transmission is still challenging. Our knowledge on the effect of upper respiratory tract infections (URTI) on male reproductive system is also scarce. Apart from negative effect of fever on spermatogenesis virtually no study has been able to compare reproductive parameters in men with COVID-19 or other URTI with predisease data. Eleven men who developed symptoms of URTI during the first and second wave of COVID-19 pandemic and who had preexistent fertility and hormonal data, participated in the study leaving sperm and blood samples. Three additional subjects were recruited among proven SARS-CoV-2 positive male hospital workers (without previous data). SARS-CoV-2 RNA was present in the ejaculate from 2 of 5 (40%) young men with mild COVID-19. In one of them viral particles could be detected in the semen sample 2 weeks after the first sampling. Men with any URTI showed higher LH ( p = 0.02 ), lower sperm concentration ( p = 0.047 ), and free testosterone ( p = 0.008 ) when compared to their samples delivered 10 years earlier. When SARS-CoV-2 positive subjects were compared to subjects with other URTIs, no difference in levels of reproductive parameters or inflammatory markers was seen. In conclusion, SARS-CoV-2 RNA can be present in the ejaculate but does not seem to affect reproductive parameters any more than other viruses. However, mild URTI was shown to affect the sperm concentration, LH, and free testosterone negatively.

Testosterone and the Amygdala's Functional Connectivity in Women and Men.

The amygdala contains androgen receptors and is involved in various affective and social functions. An interaction between testosterone and the amygdala's functioning is likely. We investigated the amygdala's resting-state functional connectivity (rsFC) network in association with testosterone in 94 healthy young adult women and men (final data available for analysis from 42 women and 39 men). Across the whole sample, testosterone was positively associated with the rsFC between the right amygdala and the right middle occipital gyrus, and it further predicted lower agreeableness scores. Significant sex differences appeared for testosterone and the functional connectivity between the right amygdala and the right superior frontal gyrus (SFG), showing higher testosterone levels with lower connectivity in women. Sex further predicted the openness and agreeableness scores. Our results show that testosterone modulates the rsFC between brain areas involved in affective processing and executive functions. The data indicate that the cognitive control of the amygdala via the frontal cortex is dependent on the testosterone levels in a sex-specific manner. Testosterone seems to express sex-specific patterns (1) in networks processing affect and cognition, and (2) in the frontal down-regulation of the amygdala. The sex-specific coupling between the amygdala and the frontal cortex in interaction with the hormone levels may drive sex-specific differences in a variety of behavioral phenomena that are further associated with psychiatric illnesses that show sex-specific prevalence rates.

Changes in surrogate markers of intestinal epithelial injury and microbial translocation in young and older men during prolonged occupational heat stress in temperate and hot conditions.

Exertional heat stress can cause damage to the intestinal epithelium and disrupt gastrointestinal barrier integrity, leading to microbial translocation (MT) linked to the development of heat stroke. This study aimed to assess age-related differences in markers of intestinal epithelial injury and MT following non-heat stress and high-heat stress exercise in healthy young and older men. Markers of intestinal epithelial injury (intestinal fatty acid-binding protein-'IFABP') and MT (soluble cluster of differentiation 14-'sCD14'; and lipopolysaccharide-binding protein-'LBP') were assessed in healthy young (18-30 y, n = 13) and older (50-70 y) men (n = 12). Blood samples were collected before, after 180min of moderate-intensity (metabolic rate: 200 W/m2) walking and following 60min recovery in either a non-heat stress [temperate: 21.9°C, 35% relative humidity (RH)] or high-heat stress (hot: 41.4°C, 35% RH) environment. There were no differences in IFABP and sCD14 between the young and older groups in the temperate condition, while LBP was greater in the older group (+ 0.66 ug/mL; + 0.08 to + 1.24 ug/mL). In the hot condition, the older group experienced greater increases in IFABP compared to the young group (+ 712pg/mL/hr; + 269 to + 1154pg/mL/hr). However, there were no clear between-group differences for sCD14 (+ 0.24 ug/mL/hr, - 0.22 to + 0.70 ug/mL/hr) or LBP (+ 0.86 ug/mL/hr, - 0.73 to + 2.46 ug/mL/hr). While older men may experience greater intestinal epithelial injury following exercise in the heat; this did not lead to a greater magnitude of microbial translocation relative to their younger counterparts.

The Effect of Massage on the Exhausted Aerobic Exercise-Induced Muscle Damage Indicators in Healthy Young Men

Background: Muscle damage and soreness caused by intense exercise are problems experienced by sedentary people whose suitable solution is an essential topic in research. Objectives: This study aimed to evaluate the effect of massage on the response of recovery creatine kinase (CK) and lactate dehydrogenase (LDH) following exhausted aerobic exercise. Methods: A total of 20 sedentary university male students (26.9 ± 2.7 y, BMI: 23.1 ± 1.6) participated voluntarily in the study. The subjects were randomly divided into two groups of exercise with massage group (mas, n = 10) and a control group (con, n = 10). Subjects run on a treadmill to the point of exhaustion. After that, the group had effleurage and petrissage massage for 20 min. Then, serum CK and LDH were measured, and the results were extracted using analysis of variance with repeated measures and post hoc Bonferroni test at the P &lt; 0.05 level. Results: Both groups significantly increased CK and LDH levels after the exercise session. There was no significant difference between the two groups immediately after the massage intervention (P &gt; 0.05). In addition, there was a significant difference between the two groups 24 and 48 hours after massage in the control (P &gt; 0.05), while there was no significant change in the massage group (P &lt; 0.05). Conclusions: Based on the results, massage intervention prevented the increase of CK and LDH levels at 24 and 48 hours after the exhaustive exercise session, which indicates the beneficial effect of massage.