Igor Zbigniew Zubrzycki

Background: Practical localized resistance tasks involving functionally divergent muscle groups may produce different systemic biochemical responses, although neither task isolates a single muscle. Methods: In this exploratory, nonrandomized, order-balanced within-participant crossover study, 102 young adults completed bilateral seated plantar flexion and unilateral elbow flexion, with 51 participants assigned by alternation to each condition sequence. The analysis-ready biochemical dataset contained complete observations for 102 participants. Blood was collected before and 2–3 min after each condition. We analyzed plasma glucose and lactate and serum total cholesterol, HDL-C, LDL-C, triglycerides, creatine kinase, lactate dehydrogenase, GGT, and cortisol. Linear mixed-effects models included exercise condition, sampling time, study period, assigned sequence, and their respective interactions with sampling time as fixed effects. Participant and participant-specific study visit were included as random intercepts where supported by the model. The exercise condition × time interaction remained the primary contrast, and Holm correction was applied across the ten predefined biochemical outcomes. Linear mixed-effects models included exercise condition, sampling time, study period, assigned sequence, and their respective interactions with sampling time as fixed effects. Participant and participant-specific study visit were included as random intercepts where supported by the model. The exercise condition × time interaction remained the primary contrast, and Holm correction was applied across the ten predefined biochemical outcomes. Results: After adjustment for period and sequence and Holm correction across the ten primary interaction tests, cortisol remained the only statistically significant exercise condition × time interaction (149.219 nmol·L⁻¹, 95% CI 62.338 to 236.099; unadjusted p = 0.000821; Holm-adjusted p = 0.008). Glucose showed a negative interaction estimate (−7.013 mg·dL⁻¹, 95% CI −12.238 to −1.788; unadjusted p = 0.009), but did not remain significant after Holm correction (adjusted p = 0.078). No period × time or sequence × time effect remained statistically significant after correction. Sensitivity analyses were not fully concordant with the primary model, supporting cautious interpretation of the cortisol finding. Conclusions: These findings describe immediate responses to two non-equivalent multi-muscle tasks and cannot be attributed to selective soleus or biceps-brachii activation, fiber-type composition, or muscle-specific substrate use.

Background: Strongman competitions impose extreme mechanical and metabolic stress on the shoulder girdle, yet quantitative neuromuscular responses under real competition conditions remain poorly characterized. Methods: Ten elite strongmen (Tier 4) and ten age-matched trained controls (Tier 2) completed an official Strongman Champions League competition protocol. Surface EMG was recorded from seven shoulder-girdle muscles during maximal voluntary contraction (MVC) trials performed immediately before and after competition. Normalized RMS amplitudes were expressed as a relative EMG index (% group peak) and analyzed using linear mixed-effects models with Benjamini–Hochberg false discovery rate (FDR) correction. Results: Within-group analyses revealed no generalized pre–post reductions in normalized EMG amplitude in either group after FDR correction. However, the control group demonstrated consistent negative pre–post trends with moderate-to-large effect sizes across several muscles, particularly for mean and median descriptors. In contrast, elite strongmen exhibited smaller and more variable changes without a systematic decline. Difference-in-differences analysis showed that temporal changes generally favored the elite group. After FDR adjustment, a significant interaction was identified for the median lower trapezius amplitude (ΔΔ = 33.76 ± 9.13, pFDR = 0.021), indicating relatively greater preservation of neuromuscular activation in elite strongmen compared with controls. No contrast demonstrated a greater decline in the elite group. Conclusions: Although most effects did not survive correction for multiple testing, the observed effect-size patterns and a significantly lower trapezius interaction suggest greater stability of neuromuscular activation in elite strongmen compared with trained, non-specialized controls. These findings support muscle- and metric-specific fatigue resistance associated with long-term strongman training.

Steroid hormones exert diverse and tissue-specific biological effects despite sharing a conserved tetracyclic scaffold. Among these, anabolic–androgenic steroids (AAS) present a longstanding paradox: structurally related compounds can elicit markedly different anabolic, androgenic, and cardiovascular outcomes. This narrative review integrates advances in steroid structural chemistry, androgen receptor (AR) biology, and intracellular signaling to elucidate the molecular mechanisms underlying anabolic–androgenic dissociation. We summarize classical genomic and emerging non-genomic modes of steroid action, emphasizing how receptor conformation, ligand-binding domain architecture, co-regulator recruitment, and signaling bias shape downstream biological responses. Particular focus is placed on the structure–activity relationships of endogenous and synthetic androgens, with C17-substitution chemistry highlighted as a central determinant of receptor affinity, metabolic stability, pharmacokinetics, and tissue selectivity. By linking molecular structure to receptor-level mechanisms, we contextualize the physiological and pathophysiological effects of major AAS classes used clinically and non-medically, including testosterone esters, 19-nor derivatives, 17α-alkylated steroids, heterocyclic compounds, and halogenated compounds. While much of the mechanistic evidence derives from preclinical models, the integrated framework presented here provides a coherent basis for interpreting divergent anabolic, androgenic, and cardiovascular effects observed in humans. Collectively, this review bridges fundamental steroid biology with applied physiology and sports medicine, offering mechanistic insight relevant to therapeutic development, anti-doping science, and risk assessment of supraphysiological androgen exposure.

Background: Vitamins are micronutrients involved in multiple physiological processes critical for athletic performance. Because athletes are often exposed to increased oxidative stress, higher metabolic turnover, and greater nutritional demands, which can potentially lead to deficiencies in vitamins, understanding vitamin supplementation as a function of sport discipline is of fundamental importance. Methods: This narrative review synthesizes research findings from the past decade, supplemented with earlier studies where necessary, focusing on vitamins A, C, D, E, and the B-complex vitamins. Peer-reviewed literature was evaluated for evidence on the prevalence of deficiencies in athletes, physiological mechanisms, supplementation strategies, and their effects on performance, injury prevention, and recovery. Results: Vitamin D deficiency is highly prevalent among athletes, particularly in indoor sports and during the winter months. Supplementation has been shown to improve musculoskeletal health and potentially reduce injury risk. The antioxidant vitamins C and E can attenuate exercise-induced oxidative stress and muscle damage; however, excessive intake may impair adaptive responses such as mitochondrial biogenesis and protein synthesis. Vitamin A contributes to immune modulation, metabolic regulation, and mitochondrial function, while B-complex vitamins support energy metabolism and red blood cell synthesis. Conclusions: Vitamin supplementation in athletes should be individualized, targeting confirmed deficiencies and tailored to sport-specific demands, age, sex, and training intensity. Dietary optimization should remain the primary strategy, with supplementation serving as an adjunct when intake is insufficient. Further high-quality, sport-specific, and long-term studies are needed to establish clear dosing guidelines and to assess the balance between performance benefits and potential risks associated with over-supplementation.

Nanotechnology offers innovative methodologies for enhancing the diagnosis and treatment of ovarian cancer by utilizing specialized nanoparticles. The utilization of nanoparticles offers distinct advantages, specifically that these entities enhance the bioavailability of therapeutic agents and facilitate the targeted delivery of pharmacological agents to neoplastic cells. A diverse array of nanoparticles, including but not limited to liposomes, dendrimers, and gold nanoparticles, function as proficient carriers for drug delivery. Nevertheless, notwithstanding the auspicious potential of these applications, challenges pertaining to toxicity, biocompatibility, and the necessity for comprehensive clinical evaluations pose considerable barriers to the widespread implementation of these technologies. The incorporation of nanotechnology into clinical practice holds the promise of significantly transforming the management of ovarian cancer, offering novel diagnostic tools and therapeutic strategies that enhance patient outcomes and prognoses. In summary, the deployment of nanotechnology in the context of ovarian cancer epitomizes a revolutionary paradigm in medical science, amalgamating sophisticated materials and methodologies to enhance both diagnostic and therapeutic outcomes. Continued research and development endeavors are essential to fully realize the extensive potential of these innovative solutions and address the existing challenges associated with their application in clinical settings.

Cirrhosis remains a significant global health burden, responsible for nearly 4% of annual deaths worldwide. Despite progress in antiviral therapies and public health measures, its prevalence has plateaued, particularly in regions affected by viral hepatitis, alcohol misuse, and metabolic syndrome. This review presents a comprehensive synthesis of the multifactorial drivers of cirrhosis, including hepatocyte injury, liver stellate cell activation, and immune-mediated inflammation. The emphasis is on the central role of metabolic dysfunction, characterized by mitochondrial impairment, altered lipid and glucose metabolism, hormonal imbalance, and systemic inflammation, in exacerbating disease progression. While current therapies may slow the progression of early-stage disease, they are very often ineffective in reversing established fibrosis. Emerging molecular strategies offer promising alternatives by targeting key pathogenic pathways. These include AMPK activators (e.g., metformin, AICAR), FGF21 analogs, and mitochondria-targeted agents (e.g., MitoQ, urolithin A, NAD+ precursors) to restore bioenergetic balance and reduce oxidative stress. Other approaches, such as mesenchymal stem cell therapy, inflammasome inhibition, and hormonal modulation, aim to suppress fibrogenesis and restore liver homeostasis. The integration of systems biology and multi-omics profiling supports patient stratification and precision medicine. This review highlights a shift toward mechanism-based interventions that have the potential to alter cirrhosis outcomes and improve patient survival.

Background/Objectives: The objective of this study was to expose the ability of neurophysiotherapeutic management to reduce spasticity through a modified Ashworth Scale. Methods: The sample, consisting of 102 subjects divided into control and study groups, was selected from an initial pool of N = 1007 patients diagnosed with stroke by a neurosurgeon that was later confirmed with imaging (MRI, CT). The study scheme included statistical differentiation between the study and control groups before and after applying specific rehabilitation programs and statistical differentiation within these groups before and after their rehabilitation procedures. Results: The results of this study revealed statistically significant improvements in reducing spasticity, as assessed by the Ashworth scale, within the group that participated in the neurorehabilitation program. It also confirmed that using neurophysiological methods is a highly effective approach to managing spasticity in post-stroke patients. Conclusions: Using neurophysiological methods in the standard physiotherapy treatment of spasticity is very effective for managing post-stroke spasticity.

This study aimed to analyze the influence of supervised 12-week walking (W) and Nordic-walking (NW) programs on changes in specific physiological parameters in middle-aged women 55.40±7.87 and 52.58±6.91 years of age, respectively. Body mass, fat tissue percentage, muscle tissue percentage, systolic blood pressure, diastolic blood pressure, resting pulse, and maximum oxygen uptake were measured at the beginning and end of the exercise program. Intra- and intergroup differences in physiological parameters as a function of the preparation period were analyzed using bootstrap analysis. Clinically reliable changes for a specific subject in the W and NW programs were analyzed using the Reliable Change Index (RCI). The results of this study indicate that more distinct differences were observed in the NW group. However, both programs improved the parameters studied. Nevertheless, an analysis of the RCI indicates that the W provides results similar to, if not better than, NW for increasing neuromuscular, cardiovascular, and cardiorespiratory fitness. This study leads us to the conclusion that the W is not less efficient than the NW for middle-aged women.

The purpose of this study was to evaluate changes in health-related parameters caused by the administration of anabolic-androgenic steroids and “fat-burning drugs” during a 6-month competition preparation period. The physiological, biochemical, and anthropometric parameters studied included serum cholesterol, triglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, aspartate aminotransferase, alanine transaminase, bilirubin, body mass, and percentage of total body fat. Changes in the parameters studied were analyzed at monthly intervals during six months of preparation for competition. The study revealed a continuous increase in body mass, accompanied by a decrease in body fat percentage to the physiologically essential level. Total cholesterol levels remined in the desirable concentration range. The mean levels of triglycerides fluctuated between borderline high and high. Mean high-density lipoprotein cholesterol levels remained within the low range, while low-density lipoprotein cholesterol fluctuated between near-optimal / above-optimal, borderline high, and high levels. Serum levels of aspartate aminotransferase and alanine transaminase remained within the high concentration. The bilirubin concentration remained in the desirable range. The blood nitrogen urea concentration fluctuated between normal and elevated levels. Sports-enhancing drugs analyzed in this study do not have an immediate detrimental impact on the selected biochemical, physiological, and anthropometric parameters that define health. Received: 16 March 2022 Accepted: 25 July 2022 Article published online: 02 December 2022 © 2022. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial-License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/). Georg Thieme Verlag Rüdigerstraße 14, 70469 Stuttgart, Germany