Effects of the Type of Exercise Training on Bone Health Parameters in Adolescent Girls: A Systematic Review.

Interventional studies offer strong evidence for exercise's osteogenic impact on bone particularly during growth. With rising osteoporosis rates in older women, enhancing bone strength early in life is crucial. Thus, investigating the osteogenic effects of different types of physical activities in young females is crucial. Despite varied findings, only two systematic reviews tried to explore this topic without examining how different types of exercise may affect bone health in adolescent girls. The first aim of this systematic review was to assess the impact of exercise training on bone health parameters in adolescent girls, and the second aim was to investigate whether the type of exercise training can modulate this effect. A systematic literature search was conducted using common electronic databases from inception - January 2023. Seven studies (355 participants) were eligible for inclusion in this systematic review. Two studies dealt with resistance training, 3 studies applied plyometric training, 1 study used team sports, and 1 study used dancing. Results indicate that plyometric training increases lumbar spine bone mass in adolescent girls. Well-designed randomized controlled trials with a proper training period (> 12 weeks) are needed to advocate a specific type of training which has the highest osteogenic effect.

Bioinformatics Analysis Identifies Key Genes in the Effect of Resistance Training on Female Skeletal Muscle Aging.

Resistance training is used to combat skeletal muscle function decline in older adults. Few studies have been designed specific for females, resulting in very limited treatment options for skeletal muscle atrophy in aging women. Here, we analyzed the gene expression profiles of skeletal muscle samples from sedentary young women, sedentary older women, and resistance-trained older women, using microarray data from public database. A total of 45 genes that were differentially expressed during female muscle aging and reversed by resistance training were identified. Functional and pathway enrichment analysis, protein-protein interaction network analysis, and receiver operating characteristic analysis were performed to reveal the key genes and pathways involved in the effects of resistance training on female muscle aging. The collagen genes COL1A1, COL3A1, and COL4A1 were identified important regulators of female muscle aging and resistance training, by modulating multiple signaling pathways, such as PI3 kinase-Akt signaling, focal adhesions, extracellular matrix-receptor interactions, and relaxin signaling. Interestingly, the expression of CDKN1A and TP63 were increased during aging, and further upregulated by resistance training in older women, suggesting they may negatively affect resistance training outcomes. Our findings provide novel insights into the molecular mechanisms of resistance training on female muscle aging and identify potential biomarkers and targets for clinical intervention.

Exercise and vascular function in sedentary lifestyles in humans.

People with sedentary lifestyles engage in minimal or no physical activity. A sedentary lifestyle promotes dysregulation of cellular redox balance, diminishes mitochondrial function, and increases NADPH oxidase activity. These changes collectively increase cellular oxidative stress, which alters endothelial function by oxidizing LDL-C, reducing NO production, and causing eNOS uncoupling. Reduced levels of nitric oxide (NO) leads to vasoconstriction, vascular remodeling, and vascular inflammation. Exercise modulates reactive oxygen species (ROS) to modify NRF2-KEAP signaling, leading to the activation of NRF2 to alleviate oxidative stress. While regular moderate exercise activates NRF2 through ROS production, high-intensity intermittent exercise stimulates NRF2 activation to a greater degree by reducing KEAP levels, which can be more beneficial for sedentary individuals. We review the damaging effects of a sedentary lifestyle on the vascular system and the health benefits of regular and intermittent exercise.

Maternal nutrition and effects on offspring vascular function.

Maternal nutrition during pregnancy may have profound effects on the developing fetus and impact risk for cardiovascular disease later in life. Here, we provide a narrative review on the impact of maternal diet during pregnancy on offspring vascular function. We review studies reporting effects of maternal micronutrient (folic acid, iron) intakes, high-fat diets, dietary energy restriction, and low protein intake on offspring endothelial function. We discuss the differences in study design and outcomes and potential underlying mechanisms contributing to the vascular phenotypes observed in the offspring. We further highlight key gaps in the literature and identify targets for future investigations.

The effects of ALK5 inhibition and simultaneous inhibition or activation of HIF-1α in melanoma tumor growth and angiogenesis.

BACKGROUND: Hypoxia is the most common signature of the tumor microenvironment that drives tumorigenesis through the complex crosstalk of a family of transcription factors called hypoxia-inducible factors (HIFs), with other intercellular signaling networks. Hypoxia increases transforming growth factor-beta (TGF-ß) expression. TGF-ß and HIF-1α play critical roles in several malignancies and their interactions in melanoma progression remain unknown. Therefore, the aim of this study was to assess the impact of inhibiting activin receptor-like kinase-5 (ALK5), a TGF-ß receptor, on the response to HIF-1α activation or inhibition in melanoma tumor progression. MATERIALS AND METHODS: Tumors were induced in C57BL/6J mice by subcutaneous inoculation with B16F10 melanoma cells. Mice were divided into HIF-1α inhibitor, ALK5 inhibitor (1 mg/kg) and HIF-1α inhibitor (100 mg/kg), ALK5 inhibitor, HIF-1α activator (1000 mg/kg), HIF-1α activator and ALK5 inhibitor, and control groups to receive inhibitors and activators through intraperitoneal injection. The expression of E-cadherin was evaluated by RT-qPCR. Vessel density and platelet-derived growth factor receptor beta (PDGFR)-ß+ cells around the vessels were investigated using immunohistochemistry. RESULTS: The groups receiving HIF-1α inhibitor and activator showed lower and higher tumor growth compared to the control group, respectively. E-cadherin expression decreased in all groups compared to the control group, illustrating the dual function of E-cadherin in the tumor microenvironment. Vascular density was reduced in the groups given HIF-1α inhibitor, ALK5 inhibitor, and ALK5 and HIF-1α inhibitor simultaneously. The percentage of PDGFR-ß+ cells was reduced in the presence of HIF-1α inhibitor, ALK5 inhibitor, HIF-1α and ALK5 inhibitors, and upon simultaneous treatment with HIF-1α activator and ALK5 inhibitor. CONCLUSION: Despite increased expression and interaction between TGF-ß and HIF-1α pathways in some cancers, in melanoma, inhibition of either pathway alone may have a stronger effect on tumor inhibition than simultaneous inhibition of both pathways. The synergistic effects may be context-dependent and should be further evaluated in different cancer types.

Neuroprotective effects of ivermectin against transient cerebral ischemia-reperfusion in rats.

Stroke is a leading cause of disability and death worldwide. Ivermectin is a broad-spectrum anti-parasitic agent with potential anti-bacterial, anti-viral, and anti-cancer effects. However, the effects of ivermectin on the brain are poorly described. This study examined the effects of ivermectin on cerebral ischemia-reperfusion (IR) in rats. A rat model of transient global IR was induced by bilateral carotid artery occlusion for 20 min. Rats received ivermectin (2 mg/kg/day, ip) one hour after inducing cerebral IR for three consecutive days at 24-h intervals. Next, we examined the effects of ivermectin on brain infarction, histopathology, malondialdehyde levels, myeloperoxidase activity, spatial learning and memory, and phospho-AMPK protein levels. The results showed that ivermectin reduced brain infarct size (P < 0.001) and histopathological changes such as cerebral leukocyte accumulation and edema (P < 0.05) compared to untreated rats with IR. Treatment with ivermectin also decreased myeloperoxidase activity (P < 0.01) and malondialdehyde levels (P < 0.05) while increasing AMPK activity (P < 0.001), memory, and learning compared to the untreated IR group. Overall, we show for the first time that ivermectin conferred neuroprotective effects in a rat model of cerebral IR. Our results indicate that three days of treatment with ivermectin reduced brain infarct size, lipid peroxidation, and myeloperoxidase activity and improved memory and learning in rats with cerebral IR. These effects likely occurred via AMPK-dependent mechanisms.

Morphine upregulates Toll-like receptor 4 expression and promotes melanomas in mice.

BACKGROUND: Morphine and other opioids are used to manage cancer-related pain; however, the role of these drugs in cancer progression remains controversial. Emerging evidence indicates that morphine can activate Toll-like receptor 4 (TLR4) and its signaling pathways, by the way the activation and expression of TLR4 can promote melanoma. In this study, we investigated the effects of morphine on the expression of TLR4 and promotion of melanoma in mice. METHODS: Mice melanoma cells (B16F10) were cultured with morphine (0.1, 1 and 10 µM) for 24 h. In the other experiment, cells were treated with morphine with or without TLR4 agonist (LPS) or antagonist (TAK-242). In in-vivo model, B16F10 cells were subcutaneously injected to C57BL/6 mice, and morphine was administrated in three different treatment protocols after developing palpable tumors (acute treatment, chronic daily injections, escalating doses of morphine). In another set of experiments, B16F10 cells were pretreated with LPS (5 µg/ml) 24 h before injection into mice. Control group received normal saline. We measured cell proliferation, the expression level of Tlr4, Nuclear factor kappa-light-chain-enhancer of activated B cells 1 (Nf-κb1) genes, TLR4 protein expression, and tumor volume. RESULTS: Chronic, acute, and escalating doses of morphine increased tumor. Morphine increased the expression of Tlr4 and Nf-κb1 regardless of the treatment protocol used. CONCLUSION: Morphine increases the progression of melanoma cancer and may be related to the increased expression of TLR4. Our results suggest that morphine should be used with caution in patients with melanoma.HighlightsMorphine increases the expression of TLR4 in melanoma.Morphine increases melanoma progression.These effects are mostly observed with chronic and escalating morphine administration.

Resistance Band Exercise: An Effective Strategy to Reverse Cardiometabolic Disorders in Women With Osteosarcopenic Obesity.

We designed to evaluate the effects of resistance elastic band exercises (REBEs) on cardiometabolic/obesity-related biomarkers in older females with osteosarcopenic obesity. Sixty-three patients (aged 65-80 years) with osteosarcopenic obesity and a body mass index exceeding 30 kg/m2 were enrolled in the study. The participants were randomly assigned to either an experimental group (REBE, n = 32) or a usual care group (n = 31). The experimental group completed a 12-week REBE program, three times a week and 60 min per session. There were decreases in lipid accumulation product (p = .033), visceral adipose index (p = .001), triglyceride-glucose-body mass index (p = .034), and atherogenic index of plasma (p = .028) in the experimental group compared with the usual care group. Our findings highlight the importance of an REBE program in improving combined cardiometabolic/obesity-related indices in older women with osteosarcopenic obesity. The incorporation of an REBE program may benefit individuals who are unable to tolerate or participate in more strenuous exercise programs.

Effect of serum magnesium levels on outcomes of patients hospitalized with COVID-19.

BACKGROUND:  The coronavirus disease 2019 (COVID-19) causes acute respiratory illness and multi-organ failure. The critical roles of magnesium in human health suggest that it could have an active role in the prevention and treatment of COVID-19. We measured magnesium levels in hospitalized COVID-19 patients concerning disease progression and mortality. MATERIALS AND METHODS:  This study was conducted in 2321 hospitalized COVID-19 patients. Clinical characteristics from each patient were recorded, and blood samples were collected from all patients upon their first admission to the hospital to determine serum magnesium levels. Patients were divided into two groups based on discharge or death. The effects of magnesium on death, severity, and hospitalization duration were estimated by crude and adjusted odds ratio using Stata Crop (version 12) software. RESULTS:  Mean magnesium levels in patients who died were higher than in discharged patients (2.10 vs 1.96 mg/dl, p 0.05). CONCLUSIONS: We found no relation between hypomagnesaemia on COVID-19 progression, although hypermagnesaemia could affect COVID-19 mortality (Tab. 4, Ref. 34).

Mental health, eating habits and physical activity levels of elite Iranian athletes during the COVID-19 pandemic.

BACKGROUND: The COVID-19 pandemic has changed life styles of millions of people worldwide. This study investigated changes in the health, physical activity levels and eating habits of elite athletes during the COVID-19 pandemic lockdown in Iran. METHODS: 383 (248 female and 135 male) elite athletes (168.82 ± 0.07 cm; 63.92 ± 7.42 kg; the body mass index (BMI): 22.3 ± 0.78 kg/m2) participated in this study. The International Physical Activity Questionnaire (IPAQ), Depression Anxiety Stress Scales (DASS-21) and the Impact of Event Scale-Revised (IES-R) study tools were used to measure levels of physical activity and mental health status, respectively. The Emotional Eater Questionnaire (EEQ) was used to assess food consumption related to emotion. Pearson and Spearman correlation analysis test were used in data analysis. RESULTS: Levels of depression and stress were mild and moderate, while levels of anxiety were severe and very severe in most elite athletes. There were levels of low emotional eating by elite athletes during the COVID-19 pandemic. Physical activity levels were negatively correlated with psychological mood measures (p≤0.05), while there were positive correlations between emotional eating behaviours and psychological mood measures (moderate correlation; p≤0.01) and light physical activity levels (weak correlation; p≤0.05). CONCLUSION: This study provides the first preliminary evidence showing that the COVID-19 lockdown conditions negatively influenced the eating habits and levels of physical activity and mental health in elite athletes. Regular high intensity physical activity as health strategy in elite athletes and the general population remains a strategy to improve overall health during the COVID-19 pandemic. Additionally, these findings suggest the need to devise strategies to improve the life styles of elite athletes during pandemics such as the Covid-19 pandemic.

CONTEXTE: La pandémie de COVID-19 a changé les modes de vie de millions de personnes dans le monde. Cette étude a examiné certains indicateurs de bonne santé, les niveaux d'activité physique et les habitudes alimentaires d'athlètes Elite iraniens pendant le confinement lié à la pandémie de COVID-19.Méthodes : 383 (248 femmes et 135 hommes) athlètes élites (168,82 ± 0,07 cm ; 63,92 ± 7,42 kg ; indice de masse corporelle (IMC) : 22,3 ± 0,78 kg/m2) ont participé à cette étude. Le questionnaire international sur l'activité physique (IPAQ), l'échelle DASS-21 (Depression Anxiety Stress Scales) et les scores de l'auto-questionnaire Impact of Event Scale-Revised (IES-R) ont été utilisés pour mesurer les niveaux respectifs d'activité physique et de l'état de santé mentale. L'Emotional Eater Questionnaire (EEQ) a été utilisé pour évaluer les altérations de la prise alimentaire liées à l'émotion. Le test d'analyse de corrélation de Pearson et Spearman a été utilisé pour l'analyse des données.Résultats : Les niveaux de dépression et de stress étaient légers et modérés, tandis que les niveaux d'anxiété étaient sévères à très sévères chez la plupart des athlètes élites. Il y avait des niveaux de faible alimentation d'origine émotionnelle chez ces athlètes pendant la pandémie de COVID-19. Les niveaux d'activité physique étaient corrélés négativement avec les mesures de l'humeur psychologique (p≤0,05), tandis qu'il y avait des corrélations positives entre les comportements alimentaires émotionnels et les mesures de l'humeur psychologique (corrélation modérée ; p≤0,01) et les niveaux d'activité physique légère (faible corrélation ; p≤0,05). CONCLUSION: Cette étude apporte une preuve préliminaire que les conditions de confinement liées au COVID-19 ont influencé négativement les habitudes alimentaires et les niveaux d'activité physique et de santé mentale chez des athlètes élites. L'activité physique régulière à haute intensité aussi bien chez les athlètes élites que pour la population générale reste une stratégie pour améliorer la santé globale pendant la pandémie de COVID-19. De plus, ces résultats suggèrent la nécessité de concevoir des stratégies pour améliorer les styles de vie des athlètes élites lors de pandémies, telles que celle de Covid-19.

High-intensity Interval Training Improves Lipocalin-2 and Omentin-1 Levels in Men with Obesity.

We investigated the effects of 12 weeks of high-intensity interval training (HIIT) on selected circulating adipokines and other cardiovascular diseases risks factors in men with obesity. Thirty men with obesity (age: 24.96±3.11 year, BMI: 30.92±1.04 kg/m2) were randomly assigned to HIIT and control groups. The HIIT group participated in a 12-week HIIT program (5×2 min interval bout at an intensity of 85-95% HRmax interspersed by 1 min passive recovery, three times per week), while the control group maintained their usual lifestyles. Blood lipids, insulin resistance, and select serum adipokines were assessed before and after 12 weeks of the intervention period. HIIT improved body composition and lipid profiles (p<0.05) and also decreased fasting insulin levels (p=0.001) and HOMA-IR (p=0.002) levels. Furthermore, HIIT increased levels of lipocalin-2 (p=0.002) while decreasing omentin-1 levels (p=0.001) in men with obesity. Changes in lcn2 and omentin-1 concentrations correlated with the changes in risk factors in the HIIT group (p<0.05). The results indicate that 12 weeks of supervised HIIT significantly improves both circulating concentrations of lcn2 and omentin-1, two recently described adipokines, and risk markers of cardiovascular diseases in men with obesity. Further research is necessary to understand the molecular mechanisms involved with these changes.

Time-dependent Effects of Moderate- and High-intensity Exercises on Myocardial Transcriptomics.

The heart is a highly adaptable organ that responds to changes in functional requirements due to exposure to internal and external stimuli. Physical exercise has unique stimulatory effects on the myocardium in both healthy individuals and those with health disorders, where the effects are primarily determined by the intensity and recovery time of exercise. We investigated the time-dependent effects of different exercise intensities on myocardial transcriptional expression in rats. Moderate intensity exercise induced more differentially expressed genes in the myocardium than high intensity exercise, while 16 differentially expressed genes were down-regulated by moderate intensity exercise but up-regulated by high intensity exercise at 12 h post- exercise. Both Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis indicated that moderate intensity exercise specifically regulated gene expression related to heart adaptation, energy metabolism, and oxidative stress, while high intensity exercise specifically regulated gene expression related to immunity, inflammation, and apoptosis. Moreover, there was increased expression of Tbx5, Casq1, Igsf1, and Ddah1 at all time points after moderate intensity exercise, while there was increased expression of Card9 at all time points after high intensity exercise. Our study provides a better understanding of the intensity dependent effects of physical exercise of the molecular mechanisms of cardiac adaptation to physical exercise.

Potential harms of supplementation with high doses of antioxidants in athletes.

Vigorous exercise generates large amounts of reactive oxygen species (ROS) as a result of the consumption of large volumes of O2 in athletes, causing some athletes to consume antioxidants in the erroneous belief that this will counteract the damaging effects of ROS. There is currently no convincing evidence to support the benefits of antioxidant supplementation in acute physical exercise and exercise training. On the contrary, exogenous antioxidants prevent some physiological functions of free radicals that are needed for cell signaling, causing higher dosages of antioxidants to hamper or prevent performance-enhancing and health-promoting training adaptation such as mitochondrial biogenesis, skeletal and cardiac muscle hypertrophy, and improved insulin sensitivity. However, there remains the perception that antioxidants can counterbalance oxidative stress and benefit exercise adaptation and performance in athletes. It is likely that the negative effects of high doses of antioxidant supplementation exceed their potential benefits. We discuss some proposed pathways of potential side effects of exogenous antioxidant supplementation in athletes.

Walking exercise and lower-body blood flow restriction: Effects on systemic inflammation, lipid profiles and hematological indices in overweight middle-aged males.

The objective of present study is to investigate the effects of walk training with and without blood flow restriction (BFR and no-BFR) on lipid profiles, inflammatory and haematological factors in over-weighed men. Participants were divided into BFR (n = 9) or no-BFR (n = 9) groups. Both groups were exposed to 8-week walk training on a treadmill: 3 sessions/week at a speed of 50 m/min, 5 sets × 2 min/session. There were differences in pre- to post-levels of (TG) and fibrinogen in the BFR group (p ≤ 0.05) that were accompanied by changes in red blood cells (RBC), haemoglobin (HGB) and haematocrit (HCT) levels (p ≤ 0.05). RBC levels were increased in the BFR group (p ≤ 0.05). The groups differed in their mean corpuscular volume (MCV) and mean corpuscular haemoglobin concentration (MCHC). These findings suggest the efficiency of BFR walk training in individuals exposed to chronic diseases associated with overweight, such as metabolic syndrome.

Effect of endothelin on sex-dependent regulation of tone in coronary resistance vessels.

BACKGROUND/AIMS: Sex dependent differences in coronary artery vasoregulation may be due to variations in responses to endogenous vasoactive compounds including endothelin (ET-1) and nitric oxide (NO). METHODS: Septal coronary arteries (<200 µm) from healthy, sexually mature male, female and ovariectomized (i.e. surgical menopause) Sprague-Dawley rats were used. Myogenic tone, measured by pressure myography, was initially determined for all vessel segments studied before and after exposure to the nonselective ETA/ETB receptor blocker, bosentan (1 µM). Vasoconstrictor responses (vascular endothelium intact) to cumulative ET-1 (10-12 - 10-9 M) were assessed in a separate set of septal coronary vessels. Additional studies, examined the vasoconstrictor effects of ET-1 after NO blockade with L-NAME (200 µM). RESULTS: Myogenic tone was 26 ± 7% in male, 20 ± 7% in female (p = 0.04 versus male) and 24 ± 3% in ovariectomized (p = NS versus male/female) vessels. Antagonism of ET-1 receptors produced a greater reduction in myogenic tone in male, compared to female rats over a similar range of intraluminal pressure (20-80 mmHg). Robust constrictor responses to cumulative concentrations of ET-1 were observed in all vessels; however, male rats exhibited greater sensitivity to vasoconstrictor effects of ET-1. After exposure to L-NAME vessel responses to ET-1 were normalized in male and female (not studied in ovariectomized) groups. CONCLUSIONS: These findings confirm marked sex differences for myogenic tone and vessel constrictor responses to ET-1 in coronary resistance vessels. Results also suggest greater sensitivity to vasoconstrictor effects of ET-1 in male coronary resistance vessels.

Physical activity and adipokine levels in individuals with type 2 diabetes: A literature review and practical applications.

We review the effects of acute and long-term physical activity on adipokine levels in individuals with type 2 diabetes (T2D). Three electronic databases were searched. Studies made in animal models were excluded, while studies based on participants with and without T2D, and also studies with type 1 diabetes were included. Of the 2,450 citations, 63 trials, including randomised control trials, cross-sectional and longitudinal studies, met our inclusion criteria. Seventy and five percent of studies reported the effects of physical activity on tumor necrosis factor-alpha (TNFα), interleukin 6 (IL-6), adiponectin, visfatin, omentin-1, and leptin levels. There are no robust results due to variations in exercise modality, intensity, duration, and also differences in cohort characteristics in the literature. Only four studies described the effects of an acute session of physical activity on adipokine levels. Overall, physical activity improves diabetes status by regulating adipokine levels. However, long-term aerobic + resistance training combined with dietary modifications is likely to be a more effective strategy for improving adipokines profiles in patients with type 2 diabetes.

Vascular and renal telomere shortening in mice exposed to chronic intermittent hypoxia.

Obstructive sleep apnea (OSA) is a chronic condition characterized by chronic intermittent hypoxia (IH) and is associated with cardiovascular (CVD) and chronic kidney diseases (CKD). Patients with OSA have increased biomarkers of aging such as telomere shortening. We used PCR to report shortened telomere lengths in aortic and renal tissues from mice exposed to 8 weeks of IH. Our data indicate that IH, a hallmark of OSA, accelerates vascular and renal aging that may contribute to OSA-induced CVD and CKD.

Magnesium intake and lung cancer risk: A systematic review and meta-analysis.

Magnesium may reduce the risk of lung cancer by affecting cell proliferation, inflammation and by preserving lung function; however, the results of epidemiological studies on the potential benefits of magnesium in lung pathology are inconclusive. We conducted this meta-analysis to investigate the association between magnesium intake and the risk of lung cancer. A total of 5 studies were extracted from PubMed, SCOPUS, and the Cochrane Review (to May 2018). These studies involved 58,5821 participants with 8,977 lung cancer cases. The pooled relative risk (RR) indicated a significant association between lung cancer incidence and magnesium intake (RR = 0.88, 95% CI = 0.79 to 0.98; p = 0.018). To investigate the cause of heterogeneity of these studies (I2 = 75.8%, p < 0.001), we performed a subgroup analysis which was affected by the mean dose of magnesium intake, where doses of magnesium intake lower than 300 mg/d significantly decreased lung cancer risk (RR = 0.83, 95% CI = 0.70 to 0.99; p = 0.034). Increasing magnesium intake doses to over 300 mg/d did not reduce the incidence of lung cancer (RR = 0.89, 95% CI = 0.78 to 1.01; p = 0.076). Our meta-analysis suggests that magnesium intake of less than 300 mg/d may have protective effects in lung cancer.

L-Arginine Improves Endurance to High-Intensity Interval Exercises in Overweight Men.

The effects of acute consumption of L-Arginine (L-Arg) in healthy young individuals are not clearly defined, and no studies on the effects of L-Arg in individuals with abnormal body mass index undertaking strenuous exercise exist. Thus, we examined whether supplementation with L-Arg diminishes cardiopulmonary exercise testing responses, such as ventilation (VE), VE/VCO2, oxygen uptake (VO2), and heart rate, in response to an acute session of high-intensity interval exercise (HIIE) in overweight men. A double-blind, randomized crossover design was used to study 30 overweight men (age, 26.5 ± 2.2 years; body weight, 88.2 ± 5.3 kilogram; body mass index, 28.0 ± 1.4 kg/m2). Participants first completed a ramped-treadmill exercise protocol to determine VO2max velocity (vVO2max), after which they participated in two sessions of HIIE. Participants were randomly assigned to receive either 6 g of L-Arg or placebo supplements. The HIIE treadmill running protocol consisted of 12 trials, including exercise at 100% of vVO2max for 1 min interspersed with recovery intervals of 40% of vVO2max for 2 min. Measurements of VO2 (ml·kg-1·min-1), VE (L/min), heart rate (beat per min), and VE/VCO2 were obtained. Supplementation with L-Arg significantly decreased all cardiorespiratory responses during HIIE (placebo+HIIE vs. L-Arg+HIIE for each measurement: VE [80.9 ± 4.3 L/min vs. 74.6 ± 3.5 L/min, p < .05, ES = 1.61], VE/VCO2 [26.4 ± 1.3 vs. 24.4 ± 1.0, p < .05, ES = 1.8], VO2 [26.4 ± 0.8 ml·kg-1·min-1 vs. 24.4 ± 0.9 ml·kg-1·min-1, p < .05, ES = 2.2], and heart rate [159.7 ± 6.3 beats/min vs. 155.0 ± 3.7 beats/min, p < .05, d = 0.89]). The authors conclude consuming L-Arg before HIIE can alleviate the excessive physiological strain resulting from HIIE and help to increase exercise tolerance in participants with a higher body mass index who may need to exercise on a regular basis for extended periods to improve their health.

An Update on COVID-19 Vaccine Induced Thrombotic Thrombocytopenia Syndrome and Some Management Recommendations.

The thrombotic thrombocytopenia syndrome (TTS), a complication of COVID-19 vaccines, involves thrombosis (often cerebral venous sinus thrombosis) and thrombocytopenia with occasional pulmonary embolism and arterial ischemia. TTS appears to mostly affect females aged between 20 and 50 years old, with no predisposing risk factors conclusively identified so far. Cases are characterized by thrombocytopenia, higher levels of D-dimers than commonly observed in venous thromboembolic events, inexplicably low fibrinogen levels and worsening thrombosis. Hyper fibrinolysis associated with bleeding can also occur. Antibodies that bind platelet factor 4, similar to those associated with heparin-induced thrombocytopenia, have also been identified but in the absence of patient exposure to heparin treatment. A number of countries have now suspended the use of adenovirus-vectored vaccines for younger individuals. The prevailing opinion of most experts is that the risk of developing COVID-19 disease, including thrombosis, far exceeds the extremely low risk of TTS associated with highly efficacious vaccines. Mass vaccination should continue but with caution. Vaccines that are more likely to cause TTS (e.g., Vaxzevria manufactured by AstraZeneca) should be avoided in younger patients for whom an alternative vaccine is available.