Healthy Males Research Articles

Intra-Rater Reliability of Panoramic Ultrasound Imaging for Determining Quadriceps Muscle Cross-Sectional Area inMiddle-Aged and Elderly Adults.

Panoramic ultrasound (US) is an extended field-of-view (EFOV) imaging technique that enables visualization of large-scale skeletal muscles. This technique has previously been found to produce valid and reliable quantifications of muscle morphology in primarily young male subjects. The purpose was to investigate the intra-rater between-session test-retest reliability of panoramic US imaging for determining vastus lateralis (VL) and rectus femoris (RF) cross-sectional area (mCSA) in healthy middle-aged to elderly adults. In this cross-sectional study, axial panoramic US images of the RF and VL muscles were captured in 23 healthy females and males aged 47 to 78. Assessed across two sessions 3-7 days apart, intra-rater reliability was evaluated by intraclass correlation coefficients (ICC3,2), within-subject coefficient of variation , standard error of measurement (SEM), and minimal detectable change (MDC). Mean mCSA for RF was mean ± SD, 7.5 ± 2.7 cm2 on both test days, with a numeric difference of 0.8%. Mean VL mCSA was 20.6 ± 6.6 cm2 and 20.5 ± 6.5 cm2 on test days 1 and 2, respectively. Test-retest ICC were: 0.997 (95% CI: 0.994-0.999) for RF and 0.995 (95% CI: 0.989-0.998) for VL. was 2.6% for RF and 2.4% for VL. SEM was 0.2 cm2 for RF and 0.5 cm2 for VL. MDC was 0.4 cm2 for RF and 1.3 cm2 for VL. In conclusion, panoramic EFOV US is a highly reliable imaging technique for assessing RF and VL mCSA in middle-aged and elderly adults. These findings endorse the clinical and research utility of EFOV US and its sensitivity for detecting even minor changes in skeletal muscle size.

Intervertebral disc deformation in the lower lumbar spine during object lifting measured in vivo using indwelling bone pins

Object lifting is often categorized into squat and stoop techniques, with the former believed to protect the back by maintaining a neutral spine, and the latter considered harmful due to spinal flexion. Despite the widespread promotion of these beliefs, there is no evidence to support such dichotomy, as spinal flexion is not conclusively linked to low back pain. This study aimed to investigate intervertebral disc deformation in the lower lumbar spine during squat and stoop lifting using indwelling bone pins. Five healthy males underwent insertion of Kirschner wires into the L3, L4, and L5 spinous processes, followed by biomechanical data collection using magnetic and optical tracking systems during upright standing, isolated flexion/extension, and object lifting with both squat and stoop techniques. Except for one subject, stoop lifting resulted in up to 90 % greater disc wedging compared to squat lifting, with a significant difference at L4/L5 (p = 0.042). The anterior annulus fibrosus experienced 10 % to 40 % more compression during stoop lifting, but no significant differences were found in posterior annulus fibrosus expansion between techniques. Lever arms were about 35 % longer during stoop compared to squat lifting. These results indicate that even though stoop lifting generally led to greater disc deformation, significant deformation was also observed during squat lifting, challenging the notion of maintaining a neutral spine with this technique. Moreover, the considerable variability observed among participants raises concerns about the suitability of current one-size-fits-all lifting guidelines.

Cardiac magnetic resonance (CMR) height-based allometric scaling in Southeast Asians; implications in the diagnosis and prognosis of left ventricular hypertrophy (LVH): the REMODEL study

Abstract Background Left ventricular hypertrophy (LVH) is a strong predictor of adverse cardiovascular outcomes (1). Although normalizing LV mass (LVM) to height exponents has been shown to reduce variability from body size, specific recommendations for height exponents are lacking due to the scarcity of normal cohorts to define appropriate height exponents (2). Cardiac magnetic resonance (CMR) is increasingly used in assessing LVM, and the existing body of research is based primarily on the MESA cohort (3). While the MESA cohort is ethnically diverse, the intrinsic effects of ethnicity may not fully be discerned if certain ethnic groups are under-represented. Purpose We aimed to demonstrate the diagnostic and prognostic implications of establishing height exponents specific to sex in a Southeast Asian cohort. Methods Non-overweight/obese Southeast Asian healthy volunteers (n=416) were used to establish appropriate height exponents and normal reference ranges of LVM. The impact of these height exponents was examined in a separate cohort of Southeast Asians with hypertension (n=878). All individuals underwent standardized cardiovascular magnetic resonance imaging (CMR). Primary outcome was a composite of acute coronary syndrome, heart failure hospitalization, stroke, and cardiovascular mortality. Cox regression analysis of various LVH measures were adjusted for 24-hour systolic blood pressure, diabetes, and hyperlipidemia. Results The height exponents for healthy females and males were 1.57 and 2.33, respectively. In patients with hypertension, sex-specific height exponents significantly increased the detection of LVH compared with body surface area (BSA) indexing (47% [n=409/878] versus 27% [n= 236/878], p<0.001). Most individuals re-classified to LVH with sex-specific height exponents were overweight (33.1%, n=58/175) or obese (64.6%, n=113/175). There were 37 primary events over 60 [37-73] months of follow-up. Regardless of indexing method, LVH was independently associated with increased adverse events (sex-specific height exponent hazard ratio (HR): 2.8 [1.25-6.29], P=0.013). The prediction ability of LVH diagnosis by sex-specific height exponents was similar to BSA indexing (HR: 5.43 [2.49-11.8], P<0.001). Conclusions Reference ranges specific to the ethnicity, sex and imaging modality are necessary to establish appropriate height exponents. Although utilizing sex-specific height exponents to index LVM resulted in significantly more LVH reclassification when compared with BSA indexing, this did not translate to a notable improvement in event prediction. Further research into alternative methods of LVM indexing is warranted.Abstract SummaryPredictive Ability of LVH Measures

Sex-specific immune responses to COVID-19 vaccination in end-stage renal disease patients

Abstract Background End-stage renal disease (ESRD) patients have muted memory B cell formation and reduced humoral responses to COVID-19 vaccination; however, early innate immune responses have yet to be characterized. Sex-stratification is also limited in COVID-19 vaccination research. Methods We collected blood before (BD1) and 1-4 days post-dose 1 (PD1) of BNT162b2 vaccination for RNA-sequencing in ESRD patients (n = 35 BD1; 18 PD1) and healthy controls (HC) (n = 31 BD1; 30 PD1). Additionally, 20 plasma cytokines were quantified in ESRD patients (n = 39 BD1, 35 PD1) and HC (34 BD1, 15 PD1). Results Transcriptional profiling of vaccine responses identified 125 significantly differentially expressed genes (DEG) (padj<0.04) in ESRD patients and 107 DEGs (padj<0.05) in HC. 71 DEGs were shared, 54 unique to ESRD, and 36 unique to HC. DEG, pathway analyses, and cytokine responses in the combined dataset showed ESRD patients were more inflamed than HC at baseline, with an elevated inflammatory cytokine profile compared to HC. These results were driven by female ESRD patients where IL-2, IL-10, and IP-10 were more significant in females (p < 0.001) compared to males (p < 0.01). While IL-6, IFN-γ, IL-13, eotaxin, were exclusively associated in females (p < 0.05). Healthy females also had a stronger immunological response to vaccination compared to healthy males. Conclusions Despite baseline inflammation, ESRD patients were able to mount similar early immune responses to vaccination as HC, with females in both populations more reactogenic than males. Sex-stratification is recommended for ongoing immunological research to better understand unique responses to COVID-19 vaccination. Key messages • End-stage renal disease patients have similar early innate immune responses to COVID-19 vaccination as healthy controls. • Sex-stratification is important to identify unique immunological responses that may be leveraged for sex-specific vaccination strategies.

The Effect of Pre-Exercise Caffeine and Glucose Ingestion on Endurance Capacity in Hypoxia: A Double-Blind Crossover Trial

The impact of caffeine and glucose supplementation in a hypoxic environment on endurance exercise performance remains inconclusive. The current study examined the effect of pre-exercise carbohydrate and caffeine supplementation on endurance exercise performance in an acute hypoxic environment. Eight healthy active young males participated in this double-blind, within-subjects crossover study. Participants ingested the test drink 60 min before exercising at 50% Wmax for 90 min on a cycle ergometer (fatiguing preload); there followed an endurance performance test at 85% Wmax until exhaustion in a hypoxic chamber (~15%O2). Participants completed four experimental trials in a randomized order: caffeine (6 mg·kg−1; Caff), glucose (1 g·kg−1; CHO), caffeine (6 mg·kg−1) + glucose (1 g·kg−1; Caff−CHO), and taste- and color-matched placebo with no caffeine or CHO (PLA). Blood samples were collected during fasting, pre-exercise, every 30 min throughout the exercise, and immediately after exhaustion. The caffeine and glucose trials significantly enhanced endurance capacity in hypoxic conditions by Caff, 44% (68.8–31.5%, 95% confidence interval), CHO, 31% (44.7–15.6%), and Caff−CHO, 46% (79.1–13.2%). Plasma-free fatty-acid and glycerol concentrations were higher in Caff and PLA than in CHO and Caff−CHO (p < 0.05). The estimated rate of fat oxidation was higher in Caff and PLA than in CHO and Caff−CHO (p < 0.05). There were no significant differences in ratings of perceived exertion between trials. In conclusion, the ingestion of caffeine, glucose, or caffeine + glucose one hour before exercising in hypoxic conditions significantly improved 85% Wmax endurance performance after prolonged exercise.

Effects of endurance exercise under hypoxic conditions on the gastric emptying rate and intestinal cell damage.

The present study examined the effects of gastric emptying rate and intestinal cell damage following a single session of endurance exercise under "hypoxic" or "normoxic" conditions at the same relative intensity. Eleven healthy males performed two trials on different days, consisting of a 60min run on a treadmill at 70% maximal running velocity (vMax) while inspiring hypoxic (FiO2: 14.5%; HYP) or normoxic air (FiO2: 20.9%; NOR). The average running velocity was 11.4 ± 0.7km/h in NOR and 10.8 ± 0.5km/h in HYP, respectively. Venous blood samples were collected to evaluate plasma intestinal fatty acid binding protein (I-FABP) as an indicator of exercise-induced intestinal cell damage. The gastric emptying rate was determined by the 13C-sodium acetate breath test. Running velocities at 70% vMax and arterial oxygen saturation were significantly lower under HYP than NOR (p < 0.001). Peak heart rate and rating of perceived exertion during exercise did not differ significantly between the trials. Maximum 13C excretion time (an indication of the gastric emptying rate) was significantly delayed in the HYP (NOR: 38.5 ± 5.0min, HYP: 45.5 ± 9.6min; p = 0.010). Furthermore, the score of nausea increased slightly, but increased significantly after exercise only in the HYP (p = 0.04). However, exercise-induced changes in plasma I-FABP, adrenaline, and noradrenaline concentrations did not differ significantly between the two trials. These results suggest that endurance exercise under hypoxic conditions impairs digestive function in the stomach compared to exercise under normoxic conditions performed at the same relative intensity.

Osteopontin as a biomarker for diagnosing the severity of osteoarthritis

Osteoarthritis (OA) is the most common type of arthritis. It is characterized by the loss of cartilage and pain ultimately leading to difficulty in movement. Glycoprotein osteopontin (OPN) is an essential regulator that plays a critical role in developing osteoarthritis. The study aims to determine the level of OPN in the serum of patients with OA and its correlation with the content of calcium (Ca), phosphorus (P), and magnesium (Mg). The study was conducted on 92 male and female patients aged between 30 and 65, categorized into mild, moderate, and severe groups through clinical examination and X-rays. The control group consist of 58 healthy males and females 30-65-year old. OPN was measured using the ELISA technique, and minerals were estimated using spectrophotometry. It was shown that in OA patients, OPN level increased highly significant when compared with the control group (10.7 ± 3.4 ng/ml) and depended on OA severity. In patients with severe OA, it was higher (47.5 ± 8.1 ng/ml) than in groups with moderate (14.8 ± 4.5 ng/ml) and mild (12.1 ± 3.1 ng/ml) extent of the disease. We showed a significant positive relationship between OPN and phosphorus levels and a negative significant correlation between OPN and calcium, calcium/phosphorus ratio, and magnesium. These findings underscore the potential of OPN as a valuable biomarker for diagnosing the severity of osteoarthritis and monitoring the effectiveness of treatment. Keywords: calcium, magnesium, osteoarthritis, osteopontin, phosphorus.

The Effects of Multiple Acute Turkesterone Doses on Indirect Measures of Hypertrophy and Metabolic Measures: A Preliminary Investigation

Turkesterone is a naturally occurring plant steroid touted for its medicinal, pharmacological, and biological properties with no reported adverse side effects compared with traditional anabolic androgenic steroids (AAS). However, this ostensible enhancement to increase muscle protein synthesis and facilitate augmented thermogenesis remains undescribed despite uninformed and potentially haphazard consumption. To investigate whether turkesterone enhances insulin-like growth factor-1 (IGF-1) and resting metabolic rate (RMR), eleven apparently healthy males (23.3 ± 2.2) volunteered to participate in the present study with samples collected pre-, 3H post-, and 24H post-ingestion. Subsequent analyses failed to reveal any significant main condition, time, or interaction main effects for serum IGF-1, RMR, lipid, and carbohydrate metabolism (p &gt; 0.05). However, non-significant serum IGF-1 concentrations increased with both turkesterone conditions and remained elevated when compared with placebo. Similarly, RMR remained elevated above baseline across the 3 h assessed. Although these data fail to fully support turkesterone as a potent anabolic supplement, nevertheless, our findings are foundational to persistently tease apart this supplement’s purported ergogenic effects and underscore its favorable hemodynamic and gastrointestinal tolerability profile. Future investigations should, therein, aim to assess turkesterone-mediated IGF-1 increases on long-term whole-muscle growth across several training sessions to further substantiate its efficacy on anabolism.

Infrared thermography: An investigative tool for detection of subclinical bleed in hemophilia on prophylaxis

Background &amp; objectives Subclinical joint bleed is a matter of concern in individuals with hemophilia on prophylaxis. Ultrasonography (USG) is mostly used for the screening of subclinical bleeds in such individuals but it has its own limitations. Thus a more comprehensive technology is required for the detection of the same. This study undertook to evaluate the efficacy of infrared thermography (IRT) for detection of subclinical joint bleeds and its comparison with ultrasonography and MRI (Magnetic Resonance Imaging), considering MRI as the gold standard. Methods Forty eight asymptomatic individuals with hemophiliacs on prophylaxis and 15 healthy males as controls were recruited. IRT, USG and MRI were done in all participants included in the study. FLIR camera systems were used for the capture of thermograms of the joints in both the study groups. Results The mean of maximum temperature difference&gt;0.5K (ΔT max &gt;0.5K) as compared to a healthy joint was considered as significant. Subclinical bleeds were detected in 23.9, 7.29 and 27.08 per cent participants by IRT, USG and MRI respectively. Sensitivity and specificity of IRT and USG was detected to be 88.4 and 97.67 per cent, and 26.9 and 99 per cent, respectively. Interpretation &amp; conclusions The findings of this study suggest that IRT is an effective tool for detection of subclinical joint bleeds in individuals with hemophilia and can be used for the monitoring of the joints in such individuals.

Study on bioequivalence and influence of obesity-related indicators on pharmacokinetics and pharmacodynamics for insulin degludec in healthy subjects

This study aimed to evaluate the bioequivalence between test and reference insulin degludec (IDeg) and the effects of body composition on pharmacokinetics and pharmacodynamics of IDeg in Chinese healthy volunteers. In this randomized, open-label, crossover trial, 30 healthy Chinese males were assigned to receive a single subcutaneous dose (0.4 IU/kg) of each formulation under 24-h euglycemic hyperinsulinaemic clamp. Body compositions were analysed prior to administration and blood samples were collected at specific times. The 90% of primary pharmacokinetic parameters and 95% of primary pharmacodynamic parameters confidence intervals for the ratio of the least-squares geometric means were all in the range of 80–125%. As the fat content level increases, Cmax, AUC0−12 and GIR-AUC0−24 decreased whereas AUC24−96 increased sequentially. Therefore, the equivalence was demonstrated between test and reference, and in healthy Chinese volunteers, higher levels of adiposity are associated with slower rates of insulin absorption and distribution and the poorer glucose-lowering effect.

Development and Evaluation of a Wearable Upper Limb Assistive Device with a Remote Center of Motion Mechanism

Workers in factories, construction sites, and farms are often exposed to the risk of physical disability and injury. Particularly, the lower back and shoulders require assistance, as injuries can make it difficult to continue working. While social concern about back injuries is high and preventive measures are taken, lesser attention is paid to shoulders, resulting in inadequate assistance and prevention mechanisms. Therefore, wearable, low-cost, and lightweight upper limb assistive devices that can be used in multiple scenarios are desired by workers. In this study, we proposed a device that uses a remote center of motion (RCM) mechanism, enabling the device to support user’s upper arm from below, and the rotational center of device to correspond with shoulder joint. The theoretical assist torque is designed to be sufficient for arm gravity compensation of Japanese males of standard body size. The calculated theoretical assist torque for each shoulder joint is about 8 Nm and maximum assist force for each arm was about 36.3 N (3.7 kgf). Experimental evaluation using a prototype of this device on three healthy adult males demonstrated a decrease in muscle activity of approximately 38% in the anterior deltoid, 31% in the middle deltoid, and 11% in the posterior deltoid as an average of all results in a dynamic experiment in which the participants performed the indicated movements.

Mechanical Mapping of the Common Carotid Artery in Healthy Individuals Aged 2 to 40 Years.

(1) Background: In 2022, the World Stroke Organization said there were more than 12.2 million new cases of stroke each year, between all ages and sexes. Six and a half million people die each year from stroke. Ischemic stroke accounts for 7.6 million (62%) cases, with 3.3 million (51%) deaths. Stroke is mainly linked to the atherosclerosis of a large artery. (2) Objective: Since the carotid artery directly supplies the brain, we used age-dependent mechanical mapping on the healthy common carotid artery (CCA) with the aim of being able to predict and thus potentially prevent ischemic stroke. (3) Methods: We assessed the CCA stiffness of 95 healthy control (CTL) females (2.23-39.46 years) and 107 healthy CTL males (2.85-40 years). Cine-loops of B-mode CCA data were digitally recorded with conventional medical ultrasound devices. Arterial wall elastic moduli were estimated offline using a proprietary non-invasive imaging-based biomarker algorithm (ImBioMark). Statistical analyzes were carried out with Excel software. (4) Results: Females showed a linear regression profile of CCA elastic moduli ranging from 41 ± 2 kPa to 54 ± 17 kPa (R2 = 0.88), while males showed one ranging from 38 ± 5 kPa to 63 ± 22 kPa (R2 = 0.83). For qualitative and quantitative illustrations, the elastic modulus data of CTLs were compared with those of subjects with Kawasaki disease and subjects born prematurely, respectively. (5) Conclusions: This study introduced some fundamental features of the mechanical evolution of the CCA as a function of age (2-40 years). Since atherosclerotic arteriopathy starts early in life, this gives the ability to predict risks of stroke and other cardiovascular diseases with the possibility of applying a more comprehensive range of potential preventive measures early in life. This is consistent with preventive medicine objectives which aim to be more predictive to implement pre-emptive measures as opposed to diagnostic and curative approaches.

Functional Brain Network of Trait Impulsivity: Whole-Brain Functional Connectivity Predicts Self-Reported Impulsivity.

Given impulsivity's multidimensional nature and its implications across various aspects of human behavior, a comprehensive understanding of functional brain circuits associated with this trait is warranted. In the current study, we utilized whole-brain resting-state functional connectivity data of healthy males (n = 156) to identify a network of connections predictive of an individual's impulsivity, as assessed by the Barratt Impulsiveness Scale (BIS)-11. Our participants were selected, in part, based on their self-reported BIS-11 impulsivity scores. Specifically, individuals who reported high or low trait impulsivity scores during screening were selected first, followed by those with intermediate impulsivity levels. This enabled us to include participants with rare, extreme scores and to cover the entire BIS-11 impulsivity spectrum. We employed repeated K-fold cross-validation for feature-selection and used stratified 10-fold cross-validation to train and test our models. Our findings revealed a widespread neural network associated with trait impulsivity and a notable correlation between predicted and observed scores. Feature importance and node degree were assessed to highlight specific nodes and edges within the impulsivity network, revealing previously overlooked key brain regions, such as the cerebellum, brainstem, and temporal lobe, while supporting previous findings on the basal ganglia-thalamo-prefrontal network and the prefrontal-motor strip network in relation to impulsiveness. This deepened understanding establishes a foundation for identifying alterations in functional brain networks associated with dysfunctional impulsivity.

Effectiveness of masturbation Premature ejaculation diagnostic tool in diagnosing premature ejaculation in men without vaginal intercourse over the past six months: an observational study

Background Premature ejaculation (PE) is a common concern for men and their partners, but current diagnostic tools mainly focus on men who have vaginal intercourse. The Masturbation Premature Ejaculation Diagnostic Tool (MPEDT) was created to address this gap, but its effectiveness for men who only engage in self-masturbation has not been studied. This research aimed to determine the frequency of self-reported PE patients who do not have vaginal intercourse and to evaluate the diagnostic accuracy of MPEDT for this group. Method The study involved 446 male patients aged 18 to 40, and 40 non-self-reported-PE and non-vaginal-intercourse healthy males. Participants completed the MPEDT questionnaire and reported their recent six-months sex frequency. Result Among the patients seeking treatment for PE, 21.75% had not engaged in vaginal intercourse in the past six months. Of the PE patients who completed the MPEDT questionnaire (86 patients), 90.7% were diagnosed with masturbatory-PE (MPE). The sensitivity for self-reported MPE and specificity for self-reported non-MPE were 93.02% and 72.5%, respectively. Discussion For patients who have not had vaginal intercourse in the past six months but engage in masturbation and seek treatment for PE, the PEDT may not effectively assess their ejaculatory function. The MPEDT, however, can effectively evaluate their ejaculatory function. This study also emphasizes the need for diagnostic tools tailored to this population.

Light Exposure on Alertness after Wake-Up in Healthy Men: Comparing Dim, Bright, Red, and Blue Light

Introduction: Light is a key factor in moderating human alertness, both subjective and objective. However, the methodology applies in research on the effects of exposure to light of different wavelengths and intensities on objective and subjective alertness varies greatly and evidence on objective alertness in particular is still inconclusive. Thus, the present, highly standardized within-subject laboratory study on N = 44 healthy males explored how LED light of different intensities (dim vs. bright light) and wavelengths (red vs. blue) affected objective (reaction time/RT) as well as subjective (sleepiness) alertness in the morning after wake-up. Methods: Participants spent two separate nights in the laboratory and were exposed to either one of the two light intensities or colors for 60 min after wake-up. Additionally, they indicated their sleepiness on the Karolinska Sleepiness Scale and participated in an auditory RT task before and after light intervention. It was hypothesized that both bright and blue light would lead to greater subjective and objective alertness when compared to dim and red light, respectively. Results: Results indicated that average RTs were longer for participants in the bright light condition (p = 0.004, f2 = 0.07) and that RTs decreased post-light exposure irrespective of light being dim or bright (p = 0.026, f2 = 0.07). However, dim versus bright light and RT did not interact (p = 0.758, f2 = 0.07). Chronotype was a significant covariate in the interaction of dim versus bright light and subjective sleepiness (p = 0.008, f2 = 0.22). There was no difference in RTs when comparing exposure to red or blue light (p = 0.488, f2 = 0.01). Findings on subjective sleepiness and light of different wavelengths revealed that sleepiness was reduced after light exposure (p = 0.007, f2 = 0.06), although the wavelength of light did not appear to play a role in this effect (p = 0.817, f2 = 0.06). Conclusion: Hence, neither of the hypotheses could be confirmed. However, they indicated that evening types might benefit from exposure to bright light regarding sleepiness, but not morning types.

Comparative Analysis of Verapamil Pharmacokinetics: Evaluating the Impact of Simple Suspension and Crushing Administration Methods

Background/Objective: It is not uncommon for elderly patients to experience difficulties with feeding and swallowing. In the simple suspension method, tablets are dissolved and suspended in warm water without prior crushing or decapsulation, and then administered via a tube. Despite the prevalence of this method, the pharmacokinetics of suspended tablet dosage forms remain poorly understood. Methods: Verapamil was employed in dissolution tests following both the simple suspension and crushing methods. A pharmacokinetics study was conducted on healthy adult males. Results: The resultant dissolution profiles from the two methods exhibited notable dissimilarities. Drug release from the crushed product commenced earlier than that from the simple suspension and intact tablet. Furthermore, the area under the curve for verapamil during the initial 24 h period was 1.7 and 1.3 times greater in the crushed and simple suspension groups, respectively, than in the tablet group. Conclusions: The crushing and simple suspension methods are safe techniques for administering medications to patients with dysphagia, thereby preventing aspiration. Nevertheless, the processing of medications may result in an increased frequency of adverse effects. It is recommended that the processing of medicines prior to administration be avoided.

Eicosapentaenoic Acid and Medium-Chain Triacylglycerol Structured Lipid Supplementation Improves Muscular Endurance Exercise Performance and Reduces Muscle Fatigue in Young Healthy Male

Objective Structured lipids containing medium-chain fatty acids, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) from fish oil (EPA/MCT) and it improve overall endurance. However, their effects on local muscle endurance remain unclear. This study aimed to investigate the effects of EPA/MCT intake on muscle endurance during leg extension exercises and subsequent muscle fatigue. Methods This 8-week, placebo-controlled, randomized, double-blind parallel-group trial involved 20 healthy young men. Subjects were randomly assigned to an EPA/MCT group (10 subjects) and a placebo group (PL group, 10 subjects). They consumed 4560 mg of the test food daily for 8 wk before an exercise intervention. The EPA/MCT supplement contained 600 mg of EPA, 260 mg of DHA, and 1890 mg of MCT (1110 mg of octanoic acid and 780 mg of decanoic acid). After the 8-week intervention, the subjects performed four sets of leg extension exercises at 40% of their body weight until exhaustion. The number of repetitions per set and the total repetitions across the four sets served as indicators of muscle endurance. Isometric maximum voluntary contraction (MVC), range of motion, circumference, muscle thickness, echo intensity, and muscle stiffness were measured before and after exercise to assess muscle fatigue. Results There was no difference between the groups in the number of repetitions for sets 1–4 or in the total number of repetitions during the leg extension exercise. In the EPA/MCT group, a significant negative correlation was observed between the increase in the blood EPA/AA ratio and the rate of decrease in the number of repetitions. Additionally, the decrease in MVC after exercise was significantly smaller in the EPA/MCT group than in the PL group. Conclusion Our study results suggest that an 8-week intake of EPA/MCT can increase the blood EPA/AA ratio and improve muscle endurance performance. Additionally, EPA/MCT intake reduces muscle fatigue after exercise.

Combined Method Comprising Low Burden Physiological Measurements with Dry Electrodes and Machine Learning for Classification of Visually Induced Motion Sickness in Remote-Controlled Excavator

The construction industry is actively developing remote-controlled excavators to address labor shortages and improve work safety. However, visually induced motion sickness (VIMS) remains a concern in the remote operation of construction machinery. To predict the occurrence and severity of VIMS, we developed a prototype system that acquires multiple physiological signals with different mechanisms under a low burden and detects VIMS from the collected data. Signals during VIMS were recorded from nine healthy adult males operating excavator simulators equipped with multiple displays and a head-mounted display. Light gradient-boosting machine-based VIMS detection binary classification models were constructed using approximately 30,000 s of time-series data, comprising 23 features derived from the physiological signals. These models were validated using leave-one-out cross-validation on seven participants who experienced severe VIMS and evaluated through area under the curve (AUC) scores. The mean receiver operating characteristic curve AUC score was 0.84, and the mean precision–recall curve AUC score was 0.71. All features were incorporated into the models, with saccade frequency and skin conductance response identified as particularly important. These trends aligned with subjective assessments of VIMS severity. This study contributes to advancing the use of remote-controlled machinery by addressing a critical challenge to operator performance and safety.

Regional changes in the free Achilles tendon volume in response to repeated submaximal contractions

IntroductionThe Achilles tendon (AT) may become smaller in volume following acute bouts of heavy and sustained loading likely because of transient fluid exudation to the periphery and this could augment cellular mechanotransduction and tendon adaptation. Given the structure of the AT is distinct across its length, regional changes in the free AT volume may occur in response to loading. This study aimed to investigate whether the change in tendon volume in response to repeated submaximal loading is distinct across the free AT length. MethodsSixteen ATs of healthy males and females (age 24.4 ± 9.4 years, body mass 70.9 ± 16.1 kg, height 1.7 ± 0.1 m) were scanned at rest using freehand 3D ultrasound. Scanning was done before and immediately after submaximal (75 %) voluntary isometric plantarflexion contractions (8 s) involving four sets of ten repetitions. Regional volumetric changes were assessed across the free AT length by dividing the tendon into distal, mid, and proximal regions. ResultsSignificant reduction in the free AT volume occurred across all tendon regions in response to the intervention, however, the mid- region exhibited the greatest reduction in volume compared to the proximal region (P = 0.025). DiscussionThe fact that volume reduction was greatest in the mid-region compared to the proximal region of the free AT may suggest greater tendon adaptation, via mechanotransduction pathways, in the mid-region and this may be important for tendon health and injury prevention.

Neural and Muscular Determinants of Performance Fatigability Are Independent of Work and Recovery Durations During High-Intensity Interval Exercise in Males

ABSTRACT The present study aimed to investigate the effect of two protocols of high-intensity interval exercise (HIIE) on performance fatigability and its neural and muscular determinants. On different days, 14 healthy males performed two HIIE protocols with different work and recovery durations (matched for total duration, work and recovery intensities, and density): 1) 4 × 4 min at 90% HRpeak,180-s recovery at 70% HRpeak; and 2) 16 × 1 min at 90% HRpeak, 45-s recovery at 70% HRpeak. Pre- to post-HIIE reduction in maximal voluntary isometric contraction (MVIC) was used as marker of performance fatigability, while voluntary activation (VA) and potentiated quadriceps twitch force (Qtw) as markers of the neural (i.e. central fatigue) and muscular (i.e. peripheral fatigue) determinants, respectively. In addition, pre- to post-HIIE reduction in twitch force stimulated at 100 Hz (Qtw100) and 10:100 Hz ratio (Qtw10:Qtw100) were used as markers of high- and low-frequency performance fatigability, respectively. The MVIC, VA, Tw, Qtw100, and Qtw10:Qtw100 ratio decreased similarly from pre- to post-HIIE in both HIIE protocols (p < .05). The rating of perceived effort, blood pH, and plasma lactate responses were similar between HIIE protocols (p > .05), but the heart rate was higher in the longer HIIE protocol (p < .05). In conclusion, performance fatigability and its neural and muscular determinants seemed to be independent of the work and recovery durations of the HIIE, at least when HIIE protocols were matched for total work duration, work and recovery intensities, and density. Further, HIIE with long work and recovery might be preferable when the intention is to stress the chronotropic response.