Sedentary Young Males Research Articles

Effects of 90-Minute Football Match on Red Blood Indices in Sedentary Young Males

While exercise-induced haemorheological alterations are well-documented in various sports, the specific impact of a football match on red blood cell (RBC) parameters remains unknown. This study investigates the acute effects of a 90-minute football match on RBC indices in sedentary young males. After inclusion and exclusion criteria, twenty (20) moderately active, non-smoking male volunteers (mean age: 20.00 ± 0.4 years) participated in the study. Venous blood samples were collected pre- and post- football match to assess RBC count, haematocrit (HCT), and plasma volume (PV). Data generated were subjected to paired student's t-tests using SPSS, to compare values between pre- and post-match measurements. A p-value of less than 0.05 was considered indicative of statistical significance. The results showed a statistically significant decrease in haematocrit (HCT) and red blood cell count (RBC) after the match (p < 0.05) when compared to pre-match values. This was accompanied by a significant increase in plasma volume (PV) (p < 0.05), which was higher than pre-match values. These changes suggest that the physiological demands of the football match influenced blood parameters, likely due to fluid shifts and haemodilution during intense physical activity. These findings suggest potential implications for exercise physiology, diagnosis, and therapy in sports medicine.

Next-generation sequencing reveals that miR-16-5p, miR-19a-3p, miR-451a, and miR-25-3p cargo in plasma extracellular vesicles differentiates sedentary young males from athletes.

A sedentary lifestyle and Olympic participation are contrary risk factors for global mortality and incidence of cancer and cardiovascular disease. Extracellular vesicle miRNAs have been described to respond to exercise. No molecular characterization of young male sedentary people versus athletes is available; so, our aim was to identify the extracellular vesicle miRNA profile of chronically trained young endurance and resistance male athletes compared to their sedentary counterparts. A descriptive case-control design was used with 16 sedentary young men, 16 Olympic male endurance athletes, and 16 Olympic male resistance athletes. Next-generation sequencing and RT-qPCR and external and internal validation were performed in order to analyze extracellular vesicle miRNA profiles. Endurance and resistance athletes had significant lower levels of miR-16-5p, miR-19a-3p, and miR-451a compared to sedentary people. Taking all together, exercise-trained miRNA profile in extracellular vesicles provides a differential signature of athletes irrespective of the type of exercise compared to sedentary people. Besides, miR-25-3p levels were specifically lower in endurance athletes which defines its role as a specific responder in this type of athletes. In silico analysis of this profile suggests a role in adaptive energy metabolism in this context that needs to be experimentally validated. Therefore, this study provides for the first time basal levels of circulating miRNA in extracellular vesicles emerge as relevant players in intertissue communication in response to chronic exercise exposure in young elite male athletes.

Endurance exercise training changes the limitation on muscle in normoxia from the capacity to utilize O2 to the capacity to transport O2.

Maximal oxygen (O2 ) uptake ( ) is an important parameter with utility in health and disease. However, the relative importance of O2 transport and utilization capacities in limiting muscle before and after endurance exercise training is not well understood. Therefore, the present study aimed to identify the mechanisms determining muscle pre- and post-endurance exercise training in initially sedentary participants. In five initially sedentary young males, radial arterial and femoral venous (blood samples), leg blood flow (thermodilution), and myoglobin (Mb) desaturation (1 H nuclear magnetic resonance spectroscopy) were measured during maximal single-leg knee-extensor exercise (KE) breathing either 12%, 21% or 100% O2 both pre and post 8weeks of KE training (1h, 3times per week). Mb desaturation was converted to intracellular using an O2 half-saturation pressure of 3.2mmHg. Pre-training muscle was not significantly different across inspired O2 conditions (12%: 0.47±0.10; 21%: 0.52±0.13; 100%: 0.54±0.01Lmin-1 , all q>0.174), despite significantly greater muscle mean capillary-intracellular gradients in normoxia (34±3mmHg) and hyperoxia (40±7mmHg) than hypoxia (29±5mmHg, both q<0.024). Post-training muscle was significantly different across all inspired O2 conditions (12%: 0.59±0.11; 21%: 0.68±0.11; 100%: 0.76±0.09mmHg, all q<0.035), as were the muscle mean capillary-intracellular gradients (12%: 32±2; 21%: 37±2; 100%: 45±7mmHg, all q<0.029). In these initially sedentary participants, endurance exercise training changed the basis of limitation on muscle in normoxia from the mitochondrial capacity to utilize O2 to the capacity to transport O2 to the mitochondria. KEY POINTS: Maximal O2 uptake is an important parameter with utility in health and disease. The relative importance of O2 transport and utilization capacities in limiting muscle maximal O2 uptake before and after endurance exercise training is not well understood. We combined the direct measurement of active muscle maximal O2 uptake with the measurement of muscle intracellular before and after 8 weeks of endurance exercise training. We show that increasing O2 availability did not increase muscle maximal O2 uptake before training, whereas increasing O2 availability did increase muscle maximal O2 uptake after training. The results suggest that, in these initially sedentary participants, endurance exercise training changed the basis of limitation on muscle maximal O2 uptake in normoxia from the mitochondrial capacity to utilize O2 to the capacity to transport O2 to the mitochondria.

Association Between Sex Hormone-Binding Globulin, Atherogenic Indices of Plasma Among Young Sedentary Males.

Males are more likely than females to suffer from cardiovascular disease (CVD). So, sex hormones may modify these variations and affect the lipid profile. We examined the relationship between sex hormone-binding globulin (SHBG) and CVD risk factors among young males in this study. Using a cross-sectional design, we measured total testosterone, SHBG, lipids, glucose, insulin, antioxidant parameters, and anthropometric factors in 48 young males in the age range of 18 to 40 years. Atherogenic indices of plasma were calculated. In this study, a partial correlation analysis was carried out to assess the relationship between SHBG and other variables after adjustment for confounders. According to the results of multivariable analyses adjusted for age and energy, SHBG had a negative correlation with total cholesterol (r = -.454, P =.010), low-density lipoprotein cholesterol (r = -.496, P =.005), quantitative insulin-sensitivity check index, and positive correlation with high-density lipoprotein cholesterol (r = .463, P =.009). No significant correlation was observed between SHBG and triglycerides (P >.05). Several atherogenic indices of plasma have a negative correlation with SHBG levels. These include Atherogenic Index of Plasma (r = -.474, P = .006), Castelli Risk Index (CRI)1 (r = -.581, P < .001), CRI2 (r = -.564, P = .001), and Atherogenic Coefficient (r = -.581, P < .001). Among young men, high plasma SHBG was associated with reduced CVD risk factors, modified lipid profile and atherogenic ratios, and better glycemic markers. Therefore, reduced SHBG concentrations could be a prognostic marker of CVD among young sedentary males.

Twelve Weeks of Aerobic Training to Increase VO₂max in Sedentary Young Males

Study purpose. The aim of this study was to verify the effect of three sessions of aerobic training, for a period of 12 weeks, on VO2max and on the distance covered during the test.&#x0D; Materials and Methods. Fifteen sedentary males were recruited in this study. VO2max was investigated using Cooper test. Aerobic intervention lasted for 12 weeks. The exercise the subjects were performing for the first 6 weeks was supervised aerobic training, 3 times per week at 60–75% of heart rate max (HRmax) (The first two weeks at 60–65 % HRmax, third and fourth week at 65–70% HRmax, fifth and sixth week at 70–75% HRmax). Afterwards, the subjects continued supervised aerobic training for 6 weeks until the twelfth week at 70–75% HRmax.&#x0D; Results. After 8 weeks of aerobic training, a significant increase in distance covered during the Cooper test (p&lt;0.001) and a significant increase in VO2max (p &lt; 0.001) were observed.&#x0D; Conclusions. In this study, it was found that 12 weeks of aerobic training have a positive impact on VO2max improvement and, therefore, completing 3 sessions of this type of training per week has a positive impact on aerobic parameters.

Gender differences in metabolic rates and thermal comfort in sedentary young males and females at various temperatures

Human metabolic rate is a fundamental and essential aspect of thermal comfort, and gender differences in metabolic rate may underlie gender differences in comfort. This study explores gender differences in physiological and subjective responses to a wide range of cold to hot temperatures. Forty healthy college students (20 females and 20 males) participated in the experiments. Subjects were sedentary, wearing 0.6 clo, staying at 26 °C for 30 min, then exposed to either at cool (14, 16, 18, 20 °C), neutral (24, 26 °C), or warm (28, 30, 32, and 34 °C) temperatures for 90 min. Both subjective questionnaires (thermal sensation, thermal comfort, thermal acceptability) and physiological measurements (metabolic rate, skin temperature, skin blood flow, and skin wettedness) were collected during the exposures. Females tend to have lower metabolic rates than males at all temperatures, although significant differences were only found at 14, 16, and 18 °C. Females tend to be cooler and less comfortable than males at cool temperatures, which could be explained by the lower metabolic rates and lower skin temperatures in females. Males tend to be warmer and less comfortable at warm temperatures, which could be explained by higher metabolic rates and higher skin wettedness in males. No significant gender differences in subjective or physiological responses were found at neutral conditions.

Effect of eccentric and concentric squat exercise on quadriceps thickness and lower extremity performance in healthy young males

Background: In clinical practice, resistance training, which includes concentric and eccentric dynamic muscle movements, is widely used by physiotherapists to strengthen the quadriceps muscle. However, although eccentric training is assumed to induce greater hypertrophy compared to concentric contractions, there are also studies reporting that similar increases in muscle thickness can be seen in both eccentric and concentric training.Objective: This study aims to assess the effect of the eccentric and concentric squat exercise on quadriceps thickness, and lower extremity performance during jumping and walking in healthy young sedentary males. Methods: Participants were randomly divided into three groups: concentric exercise group (CE; n = 19), eccentric exercise group (EE; n = 13) and control group (CG; n = 16). Both exercises were performed seven days a week, for eight weeks with a gradual strength increase. The CG was not given any exercise. Ultrasound assessment of quadriceps muscle thickness, performance in Six-Minute Walk Test and vertical jump was measured. Results: Thickness of dominant side of rectus femoris (p = .008) and vastus lateralis (p = .021) differed significantly among the three groups; post hoc analysis revealed the thickness of rectus femoris in CG was significantly lower than in the CE (p = .046) and EE (p = .006) and the thickness of vastus lateralis in the EE was significantly higher than in the CG (p = .018). Six-Minute Walk Test score in the EE was significantly higher than in the CG (p = .025) and the vertical jump score in the CG significantly lower than in the EE (p = .002) and CE (p &lt; .001). Conclusions: Eccentric and concentric training both benefits muscle hypertrophy and lower extremity functional performance. However, eccentric training also appears to offer a small advantage over concentric training.

A randomized controlled trial of enhancing hypoxia-mediated right cardiac mechanics and reducing afterload after high intensity interval training in sedentary men

Hypoxic exposure increases right ventricular (RV) afterload by triggering pulmonary hypertension, with consequent effects on the structure and function of the RV. Improved myocardial contractility is a critical circulatory adaptation to exercise training. However, the types of exercise that enhance right cardiac mechanics during hypoxic stress have not yet been identified. This study investigated how high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) influence right cardiac mechanics during hypoxic exercise A total of 54 young and healthy sedentary males were randomly selected to engage in either HIIT (3-min intervals at 40% and 80% of oxygen uptake reserve, n = 18) or MICT (sustained 60% of oxygen uptake reserve, n = 18) for 30 min/day and 5 days/week for 6 weeks or were included in a control group (CTL, n = 18) that did not engage in any exercise. The primary outcome was the change in right cardiac mechanics during semiupright bicycle exercise under hypoxic conditions (i.e., 50 watts under 12% FiO2 for 3 min) as measured by two-dimensional speckle tracking echocardiography.: After 6 weeks of training, HIIT was superior to MICT in improving maximal oxygen consumption (VO2max). Furthermore, the HIIT group showed reduced pulmonary vascular resistance (PVR, pre-HIIT:1.16 ± 0.05 WU; post-HIIT:1.05 ± 0.05 WU, p < 0.05) as well as an elevated right ventricular ejection fraction (RVEF, pre-HIIT: 59.5 ± 6.0%; post-HIIT: 69.1 ± 2.8%, p < 0.05) during hypoxic exercise, coupled with a significant enhancement of the right atrial (RA) reservoir and conduit functions. HIIT is superior to MICT in dilating RV chamber and reducing radial strain but ameliorating radial strain rate in either systole (post-HIIT: 2.78 ± 0.14 s-1; post-MICT: 2.27 ± 0.12 s-1, p < 0.05) or diastole (post-HIIT: − 2.63 ± 0.12 s-1; post-MICT: − 2.36 ± 0.18 s-1, p < 0.05). In the correlation analysis, the changes in RVEF were directly associated with improved RA reservoir (r = 0.60, p < 0.05) and conduit functions (r = 0.64, p < 0.01) but inversely associated with the change in RV radial strain (r = − 0.70, p < 0.01) and PVR (r = − 0.70, p < 0.01) caused by HIIT. HIIT is superior to MICT in improving right cardiac mechanics by simultaneously increasing RA reservoir and conduit functions and decreasing PVR during hypoxic exercise.

Improved Endothelial Function Following Eight Weeks Of Low-intensity Resistance Training In Young Adults

Cardiovascular diseases (CVD) are the leading cause of death worldwide, and compelling evidence indicates that exercise prevents and attenuates CVD. Resistance training (RT) exerts positive health effects; however, there is a lack of evidence regarding the RT intensities that could be prescribed to improve vascular endothelial function. PURPOSE: To compare the effects of two RT intensities during eight weeks on vascular endothelial function in sedentary young males. METHODS: Thirty-four sedentary men were recruited (age = 20.6 ± 1.8 yr., height = 171.3 ± 5.2 cm, weight = 65.2 ± 10.6 kg, DXA fat mass = 22.3 ± 7.4 %), and randomly assigned to a control group (CTRL, no exercise), RT at 50% of a maximum repetition [1-RM] and RT at 80% 1-RM. The RT program was performed twice a week for eight weeks, and except for the CTRL group, participants performed the same RT exercises at similar total workloads (1920 arbitrary units [AU] for the 80%RM and 1950 AU for the 50%RM). Vascular endothelial function was measured before (pre) and after (post) eight weeks by ultrasound and determined by the percentage of flow-mediated dilatation (%FMD). Mixed factorial ANOVA (3 groups x 2 measurements x 2 occlusions), effect size (ES) and 95% confidence interval (CI95%) were computed for %FMD. RESULTS: A significant triple interaction was found on %FMD (p = 0.021). The eight-week post-intervention follow-up analyses showed a significant increase (p = 0.010) in %FMD in the 50%RM (Mean = 9.93 ± 3.73%, ES = 3.70, CI95% = 1.59 to 5.79) compared to the control group (Mean = 5.72 ± 1.71%, ES = 1.67, CI95% = -0.21 to 3.55), and no significant differences between 50%RM and 80%RM (Mean = 7.90 ± 2.51%, ES = 2.18, CI95% = 0.27 to 4.10), and between 80%RM and control groups. CONCLUSION: A 50%RM intensity RT program elicited a positive vascular endothelial function adaptation following eight-weeks of training. It seems unnecessary to perform high-intensity RT to obtain arterial health benefits.

Passive Heat Therapy in Sedentary Humans Improves Aerobic Capacity and Insulin Sensitivity via Increases in Skeletal Muscle Capillarisation and eNOS

OBJECTIVESNegative associations have been reported in a sedentary Finnish population between sauna bathing and all‐cause mortality1, while a joint association of sauna bathing and cardiorespiratory fitness was seen on cardiovascular and all‐cause mortality in a more recent study2. These associations give scientific support to the ‘proverbial wisdom’ in Scandinavia that frequent sauna bathing has multiple health and fitness benefits. The first objective of the current study was to investigate the hypotheses that 1) passive heat therapy (PHT, as occurs in sauna bathing) similar to moderate intensity continuous exercise training (MICT) increases whole body insulin sensitivity and VO2max and that 2) this is the result of increases both in a) skeletal muscle capillarisation and endothelial specific eNOS content and b) mitochondrial, GLUT4 and IMTG content.METHODSTwenty young sedentary males (21 ± 1 years; Body Mass Index (BMI) 25 ± 1 kg/m2) were allocated to either 6 weeks of PHT (n=10; 40–50 min at 40°C in a heat chamber, 3 x per week) or MICT (n=10; time matched cycling at ~65% VO2peak). VO2peak and whole‐body insulin sensitivity were measured and muscle biopsies were taken from the vastus lateralis muscle pre and post the interventions. Immunofluorescence microscopy was used to assess changes in capillarisation measures and endothelial specific eNOS content, as described before 3 and skeletal muscle mitochondrial density, GLUT4 content and IMTG content as described elsewhere4.RESULTSPHT and MICT increased VO2peak (PHT 5%, MICT 7%; P&lt;0.05) and insulin sensitivity index (ISI, Matsuda) (PHT 15%, MICT 36%; P&lt;0.05). PHT and MICT both increased capillary density, capillary–fibre perimeter exchange index, and endothelial specific eNOS content (Table 1). However, unlike MICT (P&lt;0.05) PHT did not increase mitochondrial density (P=0.443), total GLUT4 content (P=0.217) and IMTG content (P=0.957).CONCLUSIONThis study is the first to show that 6 weeks PHT induces similar increases in aerobic capacity and whole‐body insulin sensitivity as a time matched traditional MICT intervention. The study also shows and that these improvements coincide with increases in skeletal muscle capillarisation and endothelial specific eNOS content similar in magnitude to MICT. As skeletal muscle mitochondrial density, GLUT4 content and IMTG concentration were not changed by PHT the data suggest that the microvascular adaptations alone are responsible for the observed effects. This leads to the conclusion that PHT (and sauna bathing) may be effective alternative interventions to achieve significant health benefits in the large and growing population of sedentary and elderly people unable to exercise or to chronically adhere to high physical activity levels.Support or Funding InformationNAThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Association of skeletal muscle and serum metabolites with maximum power output gains in response to continuous endurance or high-intensity interval training programs: The TIMES study – A randomized controlled trial

BackgroundRecent studies have begun to identify the molecular determinants of inter-individual variability of cardiorespiratory fitness (CRF) in response to exercise training programs. However, we still have an incomplete picture of the molecular mechanisms underlying trainability in response to exercise training.ObjectiveWe investigated baseline serum and skeletal muscle metabolomics profile and its associations with maximal power output (MPO) gains in response to 8-week of continuous endurance training (ET) and high-intensity interval training (HIIT) programs matched for total units of exercise performed (the TIMES study).MethodsEighty healthy sedentary young adult males were randomized to one of three groups and 70 were defined as completers (> 90% of sessions): ET (n = 30), HIIT (n = 30) and control (CO, n = 10). For the CO, participants were asked to not exercise for 8 weeks. Serum and skeletal muscle samples were analyzed by 1H-NMR spectroscopy. The targeted screens yielded 43 serum and 70 muscle reproducible metabolites (intraclass > 0.75; coefficient of variation < 25%). Associations of baseline metabolites with MPO trainability were explored within each training program via three analytical strategies: (1) correlations with gains in MPO; (2) differences between high and low responders to ET and HIIT; and (3) metabolites contributions to the most significant pathways related to gains in MPO. The significance level was set at P < 0.01 or false discovery rate of 0.1.ResultsThe exercise programs generated similar gains in MPO (ET = 21.4 ± 8.0%; HIIT = 24.3 ± 8.5%). MPO associated baseline metabolites supported by all three levels of evidence were: serum glycerol, muscle alanine, proline, threonine, creatinine, AMP and pyruvate for ET, and serum lysine, phenylalanine, creatine, and muscle glycolate for HIIT. The most common pathways suggested by the metabolite profiles were aminoacyl-tRNA biosynthesis, and carbohydrate and amino acid metabolism.ConclusionWe suggest that MPO gains in both programs are potentially associated with metabolites indicative of baseline amino acid and translation processes with additional evidence for carbohydrate metabolism in ET.

Protein Supplementation During a 6-Month Concurrent Training Program: Effect on Body Composition and Muscular Strength in Sedentary Individuals.

We examined the effect of a protein supplement on muscular strength and body composition during 6 months of a 5 days/week concurrent strength and endurance training program. Sedentary males (n = 26) and females (n = 25), 18-25 years, were randomly assigned to receive a protein (PRO, 42g/serving) or carbohydrate (CON) supplement twice daily. Strength and body composition (dual-energy X-ray absorptiometry) were assessed at baseline, 3 (3M), and 6 (6M) months. Protein intake was higher in PRO (PRO: 2.2g/kg; CON: 1.1g/kg; p < .001). Females in both groups gained similar strength at 3M and 6M in bench press and hip sled. Males in PRO gained more bench press strength at 3M (PRO: 24.6 ± 3.2kg; CON: 14.3 ± 3.8kg; p = .06) and 6M (PRO: 34.4 ± 4.3kg; CON: 18.7 ± 5.1kg; p = .03) and hip sled strength at 3M (PRO: 67.7 ± 9.2kg; CON: 40.8 ± 10.8kg, p = .07) and 6M (PRO: 94.0 ± 10.6kg; CON: 65.1 ± 12.4kg; p = .09) compared with CON. Females in PRO experienced a greater reduction in fat mass over the course of the study (6M) than CON (PRO: -1.7 ± 0.5kg; CON: 0.1 ± 0.5kg; p = .06). Changes in lean mass were similar for females in PRO and CON. Loss in fat mass was similar for males in PRO and CON at 3M and 6M. Males in PRO gained more lean mass at 3M compared with CON (PRO: 3.2 ± 0.3kg; CON: 2.2 ± 0.4kg; p = .1) but similar gains at 6M (PRO: 2.6 ± 0.4kg; CON: 2.2 ± 0.5kg; p = .6). The results of this study demonstrate that PRO used during a concurrent training program may augment positive changes in body composition in young sedentary males and females, and strength gains in males.

Carotid Arterial Stiffness and Hemodynamic Responses to Acute Cycling Intervention at Different Times during 12-Week Supervised Exercise Training Period.

This paper studied the alterations in arterial stiffness and hemodynamic responses during resting state and immediately following acute cycling intervention at different times across 12-week supervised exercise training. Twenty-six sedentary young males participated in the exercise training program at moderate intensity. Arterial stiffness and hemodynamic variables of the right common carotid artery were measured and computed during resting state and immediately following acute cycling intervention at weeks 0, 4, 8, and 12. Across the 12-week exercise training, carotid arterial stiffness was decreased at weeks 8 and 12 and hemodynamic variables were improved at week 12 during resting state. In response to acute cycling intervention, carotid arterial stiffness exhibited an acute increase foremost at 8 weeks, and arterial maximal and mean diameters showed acute decreases at weeks 0 and 4. Despite significant differences in arterial stiffness and hemodynamic variables between resting state and immediately after acute intervention for each time period, these differences presented a progressive decrease across the 12-week exercise training. In conclusion, long-term exercise training not only improved carotid arterial stiffness and hemodynamic alterations when at rest but also negated the acute responses of carotid arterial stiffness and hemodynamic variables to acute cycling intervention.

Influence of a self-regulated cognitive dual task on time to failure and complexity of submaximal isometric force control.

To determine the effects of performing a self-regulated cognitive dual task on time to failure and neuromuscular force control during submaximal isometric contractions. Fifteen young sedentary males performed isometric contractions at 50% of each individual's maximal voluntary contraction (MVC) under single-task (without cognitive load) and dual-task (with self-regulated mathematical task) conditions. Force signal complexity and biceps brachialis muscle activity were determined at the start, middle, and end of each trial. The slope of the linear regression of median frequency determined the rate of muscle fatigue. Force-task error was established as any amplitude percentage greater or less than 50% MVC. The dual-task condition resulted in a 42s longer time to failure than the single-task condition. EMG amplitude did not differ between conditions. The rate of muscle fatigue was higher in the single-task (- 0.35%/s) than the dual-task (- 0.2%/s) condition. Force signal complexity was, on average, 22% lower in the dual-task condition. The dual-task condition, as compared to the single-task condition, elicited a higher rate of force-task error below (6.37 versus 4.76%) and over (2.11 versus 1.68%) the force threshold. The dual-task condition resulted in a longer time to failure and decreased motor output complexity and fatigue rate when performing a submaximal force task. As the dual task also increased the force-task error, we suggest cognitive dual tasks as a possible strategy for delaying fatigue in sedentary young males when exerting submaximal isometric force, contributing to neuromuscular training when error in force control can be ignored.

Aerobic Interval Training Prevents Age-Dependent Vulnerability to Atrial Fibrillation in Rodents.

Aims: Increasing age is the most important risk factor for atrial fibrillation (AF). Very high doses of exercise training might increase AF risk, while moderate levels seem to be protective. This study aimed to examine the effects of age on vulnerability to AF and whether long-term aerobic interval training (AIT) could modify these effects.Methods: Nine months old, male Sprague-Dawley rats were randomized to AIT for 16 weeks (old-ex) or to a sedentary control group (old-sed), and compared to young sedentary males (young-sed). After the intervention, animals underwent echocardiography, testing of exercise capacity (VO2max), and electrophysiology with AF induction before ex vivo electrophysiology. Fibrosis quantification, immunohistochemistry and western blotting of atrial tissue were performed.Results: Sustained AF was induced in vivo in 4 of 11 old-sed animals, but none of the old-ex or young-sed rats (p = 0.006). VO2max was lower in old-sed, while old-ex had comparable results to young-sed. Fibrosis was increased in old-sed (p = 0.006), with similar results in old-ex. There was a significantly slower atrial conduction in old-sed (p = 0.038), with an increase in old-ex (p = 0.027). Action potential duration was unaltered in old-sed, but prolonged in old-ex (p = 0.036). There were no differences in amount of atrial connexin 43 between groups, but a lateralization in atrial cardiomyocytes of old-sed, with similar findings in old-ex.Conclusion: AF vulnerability was higher in old-sed animals, associated with increased atrial fibrosis, lateralization of connexin-43, and reduced atrial conduction velocity. AIT reduced the age-associated susceptibility to AF, possibly through increased conduction velocity and prolongation of action potentials.

Bone metabolism in response to oat bran consumption and jogging exercise in young males

Adopting a physically active lifestyle along with consumption of nutritional supplementation is a strategy for improving health-related quality of life. We aimed to investigate the combined effects of oat bran consumption and jogging exercise compared to oat bran consumption alone and jogging exercise alone on bone metabolism in young males. Forty-seven sedentary male university students with mean age 20.9 ± 1.7 years were recruited. They were randomly assigned into sedentary control (C), oat bran supplementation alone (OB), exercise alone (EX) and combined oat bran and exercise (OBEX) groups. The participants in OB and OBEX group consumed 18 g of oat bran powder with 3.6 g of β-glucan daily for 8 weeks. The participants in Ex and OBEx group performed jogging exercise with moderate intensity, i.e. 55–70% of their age-predicted HRmax, 30 min per day, 3 days per week for 8 weeks. Participants’ anthropometric parameters and bone metabolism markers were measured at pre- and post-intervention. Repeated measures ANOVA was performed for statistical analysis. In OB group, no significant changes in bone metabolism markers were observed. In EX group, there was a significant increase (p < 0.05) in carboxyterminal telopeptide of type 1 collagen (CTX-1). However, there were no significant changes in bone metabolism markers in OBEX group. Eight weeks of jogging exercise alone elicited significant effects on bone turnover marker in young sedentary males. Nevertheless, future studies with longer exercise duration and higher dosage of oat bran are warranted to investigate the combined effects of jogging exercise and oat bran consumption on bone metabolism markers in this population.

The effects of combined probiotic ingestion and circuit training on muscular strength and power and cytokine responses in young males.

To our knowledge, the efficacy of combined probiotic supplementation with circuit training has not been evaluated. Thus, we investigated the effects of probiotic supplementation combined with circuit training on isokinetic muscular strength and power and cytokine responses in young males. Forty-eight healthy sedentary young males were recruited and randomised into 4 separate groups: sedentary placebo control, probiotics (P), circuit training with placebo (CT), and circuit training with probiotics (CTP). Participants in the CT and CTP groups performed circuit training 3 times/week with 2 circuits of exercises from weeks 1-8 followed by 3 circuits of exercises from weeks 9-12. Participants in the P and CTP groups consumed multi-strain probiotics containing 3 × 1010 colony-forming units of Lactobacillus acidophilus, L. lactis, L. casei, Bifidobacterium longum, B. bifidum and B. infantis twice daily for 12 weeks. Measurements of body height and weight, blood pressure, resting heart rate, blood samples, and isokinetic muscular strength and power were carried out at pre- and post-tests. Isokinetic knee strength and power in CT and CTP groups were significantly higher (P < 0.05) at post-test. In addition, interleukin (IL)-10 concentration was significantly increased (P < 0.0001) at post-test in P and CT but a trend toward significant increase in CTP (P = 0.09). Nevertheless, there was no significant difference in IL-6. This study suggests that 12 weeks of circuit training alone and the combination of circuit training and probiotic consumption improved muscular performance while circuit training alone and probiotics alone increased IL-10 concentration.

Muscular contraction frequency does not affect plasma homocysteine concentration in response to energy expenditure- and intensity-matched acute exercise in sedentary males

Acute exercise seems to increase total plasma homocysteine (tHcy); since this variable associated with cardiovascular risk, it is important to understand the determinants of its response to all types of exercise. The aim of this study was to examine the impact of cycling at 2 different rates of muscle contraction on the complete tHcy kinetics. Eight young sedentary males were required to complete 2 isocaloric (400 kcal) acute exercise trials at 50% peak oxygen uptake on separate occasions at 50 or 80 rpm. Blood samples were drawn at different points before (4 h before exercise and immediately before exercise), during (10, 20, 30, 45, and 60 min during exercise), and after exercise (immediately and 19 h after exercise). Dietary and lifestyle factors were controlled during the research. Maximum tHcy occurred during exercise for both conditions (50 rpm: 11.4 ± 2.7 μmol·L-1; 80 rpm: 10.8 ± 3.2 μmol·L-1). From this point onwards tHcy declined until the cessation of exercise and continued descending below pre-exercise values at 19 h postexercise (p < 0.05). No hyperhomocysteinemia were observed at any sampling point in both trials. In conclusion, the different muscular contraction frequency during exercise has no impact on tHcy during an acute bout of exercise in sedentary individuals, when at least 400 kcal are spent during exercise and the nutritional status for folate, B12, and B6 is adequate. This information is relevant to further inform healthy exercise prescription, not only in terms of duration and intensity of exercise, but also taking into account frequency of contraction.

Effects of probiotics supplementation and circuit training on immune responses among sedentary young males.

Growing evidence suggests that probiotics may have positive benefits on immune responses following endurance exercise. However, little attention has been given to its possible beneficial effects on immune responses following resistance exercise. Forty-one healthy sedentary males were recruited and randomised into four groups: sedentary control with placebo (C), probiotics (P), circuit training with placebo (Ex), and circuit training with probiotics (PEx) groups. Participants in the Ex and PEx groups performed a progressive load of circuit training at 3 times/week for 12 weeks. Each circuit comprised 10 exercises with work to rest ratio of 1:2. Participants consumed either multi-strain probiotics or placebo twice daily for 12 weeks. Body height and weight, blood pressure, resting heart rate, saliva and blood samples were collected at pre- and post-tests. Saliva flow rate and salivary IgA, α-amylase, lactoferrin and lysozyme responses were not significantly different (P>0.05) between groups and also between pre- and post-test within each group. Similarly, total leukocytes, total lymphocytes, T lymphocytes, T-helper, T-cytotoxic, B lymphocytes, and natural killer cells counts were not significantly affected (P>0.05) by the probiotics and/or circuit training. However, circuit training significantly increased (P<0.05) immune cells count at post-test as compared to pre-test. Yet, a combination of circuit training and probiotics showed no significant (P>0.05) effects on immune cells count. This study did not provide enough support for the positive effects of probiotics on immune responses among sedentary young males following resistance exercise. However, 12 weeks of circuit training enhanced immune cells count.

ASSOCIATION BETWEEN SCAPULAR DYSKINESIA AND SHOULDER PAIN IN YOUNG ADULTS.

ABSTRACTObjective:To analyze the position of the scapula and its influence on shoulder pain. Methods:In this study, 30 sedentary young adults of both genders, aged 20-35 years were evaluated. The sample was divided into two groups with the same number of subjects, one group with shoulder pain and the other pain free. The analysis of the positioning of the scapula in six angles of shoulder abduction was taken 0º, 30º, 60º, 90º, 120º and 180º. Results:Comparison the left and right scapular movements in males of the pain group, there was a significant difference at 30º (p = 0.018) and 120º (p = 0.04). Comparing the right and left shoulders in the pain group, there was a significant difference at 0º (p = 0.03). Conclusion:This study concludes that changing the positioning of the scapula affects shoulder pain in sedentary young adult males at certain specific positions. Level of Evidence III, Study of non consecutive patients; without consistently applied reference ''gold'' standard.