437 research outputs found
Relationship Between Endogenous Creatine Levels and Maximal Upper Body Strength, Short Term Muscle Recovery and Body Fat In Males
Numerous studies have found creatine supplementation to positively enhance performance but no research found has examined the effects of endogenous creatine levels on performance. The purpose of this study was twofold. First we examined correlations between endogenous creatine levels and strength, absolute strength, short term muscle recovery and body fat. We also examined the effects of creatine supplementation with a sufficient washout period on plasma creatinine levels. Participants consisted of 24 healthy men who met with the experimenter twice over a 4 day period. Significant positive correlations (p .05) were found between creatine and strength, absolute strength, lean body mass and muscle recovery as a function of total weight lifted following 3 and 5 sets of the muscle fatigue protocol
THE EFFECTS OF AGING ON MYOSTATIN PATHWAY ACTIVITY AFTER THREE SEQUENTIAL BOUTS OF RESISTANCE EXERCISE
Background. Myostatin signaling serves to regulate skeletal muscle mass by influencing genes responsible for regulating satellite cell activity and by participating in glucocorticoid induced skeletal muscle atrophy; however research investigating myostatin pathway signaling is still in its infancy.Purpose. The purpose of this investigation was two-fold: 1) To examine if baseline differences in myostatin signaling exist between younger (18-35 yr) and older (65-80 yr) men. 2) To examine if short-term, chronic resistance training can ameliorate potential differences in myostatin signaling that exist between younger and older adults.Methods. Younger (n = 10; age: 21.0 ± 0.5 years, body mass: 82.3 ± 4.2 kg, height: 178.4 ± 2.2 cm, body fat percentage: 15.4 ± 2.9%) and older (n = 10; age: 66.4 ± 1.6 years, body mass: 94.2 ± 3.7 kg, height: 180.9 ± 2.2 cm, body fat percentage: 27.4 ± 1.8%) men chose to participate in the current investigation. Participants were one repetition maximum tested (1 RM) for leg press, hack squat and leg extension. Then participants underwent two familiarization sessions separated by 48 hours before partaking in three training sessions separated by 48 hours which consisted of 3 sets of 10 repetitions at 80% of 1RM for each of the previously mentioned exercises. Percutaneous muscle biopsies were collected from the vastus lateralis prior to the exercise intervention (T1), 48 hours following workout 1 (T2), 48 hours following workout 2 (T3), and 24 hours following workout 3 (T4). The mRNA expression of MYOSTATIN, ACTIVIN IIB, HSGT, TITIN CAP, FLRG, FOLLISTATIN and SMURF1 were analyzed in duplicate and expressed using the 2-∆CT method where ∆CT = (gene of interest - the average of B2M and 28S). The protein expression of phosphorylated Smad3 (pSmad3) was determined using western blotting procedures.Results. Younger men had a significantly greater 1 RM for hack squat (younger: 170.0 ± 10.9 kg, older: 105.8 ± 10.4 kg; p = 0.001), leg press (younger: 271.1 ± 14.6 kg, older: 182.7 ± 14.9 kg; p < 0.001) and leg extension (younger: 64.8 ± 4.0 kg, older: 46.7 ± 2.8 kg; p = 0.002) compared to older men. As a result the cumulative training volume was significantly greater during the training bouts in younger compared to older men (younger: 36,392 ± 1,894 kg, older: 23,724 ± 1,639 kg; p < 0.001). Three day food diaries indicated that relative caloric (young = 33.4 ± 5.1 kcal/kg/d, old = 19.5 ± 1.9 kcal/kg/d; p = 0.038), protein (young = 1.6 ± 0.2 g/kg/d, old = 0.8 ± 0.1 g/kg/d; p = 0.030), carbohydrate (young = 4.1 ± 0.6 g/kg/d, old = 2.3 ± 0.3 g/kg/d; p = 0.017) and fat (young = 1.2 ± 0.2 g/kg/d, old = 0.6 ± 0.1 g/kg/d; p = 0.006) consumption were each significantly greater in younger compared to older men. Non-parametric statistics were used for the assessment of mRNA and protein data. The only between groups differences for the mRNA expression of the genes of interest occurred at baseline (p = 0.038) and T4 (p = 0.005) for FLRG and baseline (p = 0.023) and T2 (p = 0.008) for FOLLISTATIN in which older men had significantly greater mRNA expression values compared to younger men. The only significant within group changes occurred in the mRNA expression of MYOSTATIN as older men had a significant downregulation following T3 (p = 0.047) and T4 (p = 0.013), while younger men experienced a trend decrease following T4 (p = 0.074). Significant between group differences were present in the protein expression of pSmad3 following T3 (p = 0.012) and T4 (p = 0.010).Conclusions. Baseline differences in myostatin signaling were present as older men had significantly greater mRNA levels of the myostatin binding proteins FLRG and FOLLISTATIN compared to younger men. The myostatin pathway signaling response following short-term, chronic resistance training was similar between younger and older men. However, alterations in myostatin pathway signaling following repeated resistance training bouts was more favorable in older men. Specifically, older men experienced a significant decrease in the mRNA expression of MYOSTATIN at T3 and T4. Older men also had significantly lower pSmad protein levels at T3 and T4 compared to younger men. Decrements in serum androgen concentrations appear to be primarily responsible for the loss of skeletal muscle mass with age. However, in attempt to maintain skeletal muscle mass with age positive physiological adaptations have been found to occur such as an increase in the mRNA expression of ANDROGEN RECEPTOR and myogenic regulatory factors. Results from the current investigation provide evidence that favorable adaptations occur in myostatin pathway signaling to promote skeletal muscle growth with age and following short-term, chronic resistance training
The combined effects of exercise training and ingestion of a weight loss supplement on body composition and fitness parameters in college-aged males and females
Physical determinants of Division 1 Collegiate basketball, Women’s National Basketball League and Women’s National Basketball Association athletes: with reference to lower body sidedness
In female basketball the assumed components of success include power, agility, and the proficiency at executing movements using each limb. However, the importance of these attributes in discriminating between playing levels in female basketball have yet to be determined. The purpose of this study was to compare lower body power, change of direction (COD) speed, agility, and lower-body sidedness between basketball athletes participating in Division 1 Collegiate basketball (United States), Women\u27s National Basketball League (WNBL) (Australia), and Women\u27s National Basketball Association (WNBA) (United States). Fifteen female athletes from each league (N = 45) completed a double and single leg counter-movement jump, static jump, drop jump, 5-0-5 COD Test, and an offensive and defensive Agility Test. One-way analysis of variance with post-hoc comparisons, were conducted to compare differences in physical characteristics (height, body mass, age) and performance outcomes (jump, COD, agility assessments) between playing levels. Separate dependent t-tests were performed to compare lower body sidedness (left vs. right lower-limbs) during the single-leg CMJ jumps (vertical jump height) and 5-0-5 COD test for each limb within each playing level. WNBA athletes displayed significantly greater lower body power (P = 0.01 - 0.03) compared to WNBL athletes, significantly faster COD speed (P = 0.02 - 0.03), and offensive and defensive agility performance (P = 0.02 - 0.03) compared to WNBL and Collegiate athletes. WNBL athletes also produced faster defensive agility performance compared to Collegiate athletes (P = 0.02). Further, WNBA and WNBL athletes exhibited reduced lower body sidedness compared to Collegiate athletes. These findings indicate the importance of lower body power, agility, and reduced lower body imbalances to execute more proficient on court movements, required to compete at higher playing levels.
Copyright (C) 2017 by the National Strength & Conditioning Association
Perinatal Survival and Predictors of Mortality among Mothers with Hypertensive Disorders of Pregnancy at Antenatal care Clinics in Gamo Zone Public Hospitals
BACKGROUND፡ Pregnancy induced hypertension represents a significant public health problem throughout the world, which may complicate 0.5%–10% of all pregnancies. It is the leading cause of maternal as well perinatal mortality and morbidity worldwide. Pregnancy induced hypertension is a multisystem disorder unique to pregnancy and results in high perinatal mortality. The objective of this study was to determine the survival status, incidence and predictors of perinatal mortality among mothers with pregnancy induced hypertension at antenatal clinics of Gamo Zone public hospitals.METHODS: Facility-based retrospective cohort study was conducted among selected 576(192 exposed and 384 unexposed) antenatal care attendants' record at Gamo Zone public hospitals from 1st January 2018 to 31st December 2018. Data were entered into Epi data version 3.02 and exported to SPSS V 25 for analysis. Kaplan Meier survival curve together with log rank test was fitted to test the survival time. Statistical significance was declared at Pvalue <0.05 using cox proportional hazard model.RESULT: The incidence of perinatal mortality was 124/1000 births. The cumulative proportion of surviving at the end of 4th , 8th, 12th and 16th weeks of follow-up among the exposed groups was 96.9%, 93.5%, 82.1% and 61.6% respectively whereas it was 99.5%, 98.9% and 98.5% at the end of 4th, 8th and 12th weeks of follow-up for the non-exposed groups respectively. Parity of >5(AHR: 6.3; 95%CI: 1.36,10.55), mothers who delivered at<34 weeks of gestation(AHR:7.8; 95%CI: 2.6,23.1), being preterm(AHR:6; 95%CI: 5.3,19.2), perinatal birth weight<2500gm(AHR:6.1; 95&CI: 1.01,37.9), vaginal deliveryn(AHR:2.7; 95%CI:1.13,6.84), maternal highest systolic blood pressure level >160mmHg (AHR: 2.3; 95%CI: 1.02,5.55) and prepartum onset of pregnancy induced hypertension (AHR:6; 95%CI: 5.3,19.2) were statistically significant in multivariable analysis.CONCLUSION: The risk of perinatal mortality was high among the mothers with pregnancy induced hypertension compared to those of pregnancy induced hypertension free mother,s and the perinatal mortality rate was high. High parity, low gestational age, low number of antenatal care visits, low birth weight, vaginal delivery, antepartum onset of pregnancy induced hypertension and highest maternal systolic blood pressure level were the independent predictors of perinatal mortality
Acute effects of ingesting a commercial thermogenic drink on changes in energy expenditure and markers of lipolysis
Background: To determine the acute effects of ingesting a thermogenic drink (Celsius, Delray Beach, FL) (TD) on changes in metabolism and lipolysis. Methods: Healthy college-aged male (23.2 ± 4.0 y, 177.2 ± 6.1 cm, 81.7 ± 11.3 kg, 22.8 ± 7.3 % fat; n = 30) and female (23.4 ± 3.1 y, 165.6 ± 8.7 cm, 62.1 ± 9.9 kg, 28.3 ± 7.4 % fat; n = 30) participants were matched according to height and weight to consume 336 ml of the TD or a noncaloric, non-caffeinated placebo (PLA). After a 12 h fast, participants reported for pre-consumption measures of height, weight, heart rate, blood pressure, resting energy expenditure (REE), respiratory exchange ratio (RER), glycerol and free-fatty acid (FFA) concentrations. REE and RER were determined at 60, 120, and 180 min post-consumption. Serum glycerol and FFA concentrations were determined at 30, 60, 120 and 180 min post-consumption. Results: When compared to PLA, TD significantly increased REE at 60, 120 and 180 min (p < 0.05). FFA concentrations were significantly greater in TD compared to PLA at 30, 60, 120 and 180 min post-consumption (p < 0.05). No between-group differences were found in RER. Conclusion: Acute TD ingestion significantly increased REE, FFA and glycerol appearance. If sustained, these changes may help to promote weight loss and improve body composition; however, these findings are currently unknown as are the general safety and efficacy of prolonged consumption
Dribble Deficit enables measurement of dribbling speed independent of sprinting speed in collegiate, male, basketball players
Ramirez-Campillo, R, Gentil, P, Moran, J, Dalbo, VJ, and Scanlan, AT. Dribble Deficit enables measurement of dribbling speed independent of sprinting speed in collegiate, male, basketball players. J Strength Cond Res XX(X): 000-000, 2019-The aim of this study was to determine the relationships between sprinting and dribbling speed in basketball during linear and change-of-direction (COD) sprints using total dribbling time and Dribble Deficit. Collegiate, male, basketball players (n = 10; 21.0 ± 1.6 years) performed linear and COD sprints with and without dribbling a ball. Linear dribbling sprints were measured for the dominant and nondominant hands, whereas COD dribbling sprints involved bilateral use of hands. Dribble Deficit was determined as the difference between total time (second) during each dribbling trial and the equivalent nondribbling trial for linear and COD sprints. Simple linear regression analyses were performed during linear and COD sprints to determine the relationship (R) and shared variance (R) between (a) sprinting times and total dribbling times and (b) sprinting times and Dribble Deficit. Large to very large, significant relationships were evident between linear sprinting and dribbling time for dominant (R = 0.86; R = 0.74, p = 0.001) and nondominant hands (R = 0.80; R = 0.65, p = 0.005). Trivial relationships were apparent between linear sprinting time and Dribble Deficit with dominant (R = 0.10; R = 0.01, p = 0.778) and nondominant hands (R = 0.03; R = 0.00, p = 0.940). A very large relationship was evident between COD sprinting and dribbling time (R = 0.91; R = 0.82, p < 0.001), whereas a trivial relationship was observed between COD sprinting time and COD Dribble Deficit (R = -0.23; R = 0.05, p = 0.530). Dribble Deficit eliminates the strong influence of sprinting speed on outcome measures typically seen when using tests predicated on total dribbling time. Consequently, Dribble Deficit may be of added use in basketball test batteries to measure dribbling speed across linear and multidirectional movement paths
Effect of different intensities of physical activity on cardiometabolic markers and vascular and cardiac function in adult rats fed with a high-fat high-carbohydrate diet
Background: Physical activity (PA) and diet are 2 lifestyle factors that affect cardiometabolic risk. However, data on how a high-fat high-carbohydrate (HFHC) diet influences the effect of different intensities of PA on cardiometabolic health and cardiovascular function in a controlled setting are yet to be fully established. This study investigated the effect of sedentary behavior, light-intensity training (LIT), and high-intensity interval training (HIIT) on cardiometabolic markers and vascular and cardiac function in HFHC-fed adult rats.
Methods: Twelve-week-old Wistar rats were randomly allocated to 4 groups (12 rats/group): control (CTL), sedentary (SED), LIT, and HIIT. Biometric indices, glucose and lipid control, inflammatory and oxidative stress markers, vascular reactivity, and cardiac electrophysiology of the experimental groups were examined after 12 weeks of HFHC-diet feeding and PA interventions.
Results: The SED group had slower cardiac conduction (p = 0.0426) and greater thoracic aortic contractile responses (p < 0.05) compared with the CTL group. The LIT group showed improved cardiac conduction compared with the SED group (p = 0.0003), and the HIIT group showed decreased mesenteric artery contractile responses compared with all other groups and improved endothelium-dependent mesenteric artery relaxation compared with the LIT group (both p < 0.05). The LIT and HIIT groups had lower visceral (p = 0.0057 for LIT, p = 0.0120 for HIIT) and epididymal fat (p < 0.0001 for LIT, p = 0.0002 for HIIT) compared with the CTL group.
Conclusion: LIT induced positive adaptations on fat accumulation and cardiac conduction, and HIIT induced a positive effect on fat accumulation, mesenteric artery contraction, and endothelium-dependent relaxation. No other differences were observed between groups. These findings suggest that few positive health effects can be achieved through LIT and HIIT when consuming a chronic and sustained HFHC diet
The Increasing Financial Impact of Chronic Kidney Disease in Australia
The aim of this investigation was to determine and compare current and projected expenditure associated with chronic kidney disease (CKD), renal replacement therapy (RRT), and cardiovascular disease (CVD) in Australia. Data published by Australia and New Zealand Dialysis and Transplant Registry, Australian Institute of Health and Welfare, and World Bank were used to compare CKD-, RRT-, and CVD-related expenditure and prevalence rates. Prevalence and expenditure predictions were made using a linear regression model. Direct statistical comparisons of rates of annual increase utilised indicator variables in combined regressions. Statistical significance was set at P<0.05. Dollar amounts were adjusted for inflation prior to analysis. Between 2012 and 2020, prevalence, per-patient expenditure, and total disease expenditure associated with CKD and RRT are estimated to increase significantly more rapidly than CVD. RRT prevalence is estimated to increase by 29%, compared to 7% in CVD. Average annual RRT per-patient expenditure is estimated to increase by 16%, compared to 8% in CVD. Total CKD- and RRT-related expenditure had been estimated to increase by 37%, compared to 14% in CVD. Per-patient, CKD produces a considerably greater financial impact on Australia’s healthcare system, compared to CVD. Research focusing on novel preventative/therapeutic interventions is warranted
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