Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where J Jitomir is active.

Publication


Featured researches published by J Jitomir.


Journal of The International Society of Sports Nutrition | 2007

Effects of arachidonic acid supplementation on training adaptations in resistance-trained males

Michael D. Roberts; M Iosia; Chad M. Kerksick; Lem Taylor; Bill Campbell; Colin Wilborn; Travis Harvey; Matthew B. Cooke; C Rasmussen; Mike Greenwood; Ronald L. Wilson; J Jitomir; Darryn S. Willoughby; Richard B. Kreider

BackgroundTo determine the impact of AA supplementation during resistance training on body composition, training adaptations, and markers of muscle hypertrophy in resistance-trained males.MethodsIn a randomized and double blind manner, 31 resistance-trained male subjects (22.1 ± 5.0 years, 180 ± 0.1 cm, 86.1 ± 13.0 kg, 18.1 ± 6.4% body fat) ingested either a placebo (PLA: 1 g·day-1 corn oil, n = 16) or AA (AA: 1 g·day-1 AA, n = 15) while participating in a standardized 4 day·week-1 resistance training regimen. Fasting blood samples, body composition, bench press one-repetition maximum (1RM), leg press 1RM and Wingate anaerobic capacity sprint tests were completed after 0, 25, and 50 days of supplementation. Percutaneous muscle biopsies were taken from the vastus lateralis on days 0 and 50.ResultsWingate relative peak power was significantly greater after 50 days of supplementation while the inflammatory cytokine IL-6 was significantly lower after 25 days of supplementation in the AA group. PGE2 levels tended to be greater in the AA group. However, no statistically significant differences were observed between groups in body composition, strength, anabolic and catabolic hormones, or markers of muscle hypertrophy (i.e. total protein content or MHC type I, IIa, and IIx protein content) and other intramuscular markers (i.e. FP and EP3 receptor density or MHC type I, IIa, and IIx mRNA expression).ConclusionAA supplementation during resistance-training may enhance anaerobic capacity and lessen the inflammatory response to training. However, AA supplementation did not promote statistically greater gains in strength, muscle mass, or influence markers of muscle hypertrophy.


Journal of Medicinal Food | 2008

Leucine for Retention of Lean Mass on a Hypocaloric Diet

J Jitomir; Darryn S. Willoughby

As obesity rates continue to climb, there is a pressing need for novel weight loss techniques. However, the energy-restricted diets recommended for weight loss typically result in significant amounts of lean tissue loss, in addition to the desired body fat loss. Leucine, a supported anticatabolic agent, has shown promise in research at many levels. First, leucine is known to stimulate the mammalian target of rapamycin pathway, which initiates translation and protein synthesis in muscle cells. Furthermore, leucine may help to regulate blood glucose levels by promoting gluconeogenesis. Finally, several recent studies provide evidence that leucine aids in the retention of lean mass in a hypocaloric state. The aim of this paper is to review relevant leucine research in the three areas described and assess its potential as supplement for obese individuals.


Journal of Renal Nutrition | 2009

Effects of omega-3 fatty acid supplementation on lipid levels in endstage renal disease patients.

Rodney G. Bowden; J Jitomir; Ronald L. Wilson; Mindy Gentile

OBJECTIVE Our purpose was to determine if over-the-counter fish oil improves the cardiovascular-disease risk profile of endstage renal disease patients. DESIGN This study used a double-blind, permuted-block, randomized, placebo-controlled design. The experimental intervention consisted of fish-oil concentrate supplementation, whereas corn-oil capsules were used as a control. Compliance follow-ups were performed 3 times per week. SETTING Patients of Central Texas Nephrology Associates clinics were eligible for this study. PATIENTS Exclusion criteria comprised a life-expectancy of less than 6 months, pregnancy, a history of hemodialysis or medication noncompliance, or age below 18 years. The final sample size was 87 patients. The attrition rate was 9%. INTERVENTION Participants in the experimental group consumed six 1-g soft-gel capsules of fish-oil concentrate each day for 6 months. The control group consumed corn-oil capsules, following the same protocol. Venous blood samples were acquired before and after the intervention. MAIN OUTCOME MEASURE We assessed a number of serum lipid indicators. RESULTS There were significant supplement/time interactions in low-density lipoprotein cholesterol (LDL) levels (P = .0001) and LDL particle number (P = .0001). Repeated-measures analysis of variance revealed significant time trends in high-density lipoprotein cholesterol (P = .012) and LDL (P = .001). High-density lipoprotein cholesterol levels significantly decreased in the control group, and increased in the fish-oil group, at 6 months, and LDL levels increased significantly in both groups. CONCLUSIONS The analysis indicates mixed results with respect to cardiovascular disease risk. Further research is needed to assess the benefits of an over-the-counter fish-oil supplement in the renal population.


Journal of The International Society of Sports Nutrition | 2008

The acute effects of the thermogenic supplement Meltdown on energy expenditure, fat oxidation, and hemodynamic responses in young, healthy males

J Jitomir; Erica Nassar; J Culbertson; Jen Moreillon; Thomas W. Buford; Geoffrey M. Hudson; Matthew B. Cooke; Richard B. Kreider; Darryn S. Willoughby

The purpose of this study was to evaluate the effects of a thermogenic supplement, Meltdown, on energy expenditure, fat oxidation, and hemodynamics before and after maximal treadmill exercise. In a double-blind, randomized, placebo-controlled, cross-over design, 12 male participants underwent two testing sessions after consuming either the Meltdown or placebo supplement. While in a fasted state, participants rested for one hour, orally ingested either Meltdown or placebo and rested for another hour, performed a maximal treadmill exercise test, and then rested for another hour. Throughout the testing protocol, resting energy expenditure (REE) and respiratory exchange ratio (RER) were assessed. In addition, heart rate (HR) and blood pressure (BP) were assessed before and after exercise. Meltdown increased REE significantly more than placebo at 45 min (1.44 ± 0.25 vs. 1.28 ± 0.23 kcal/min; p = 0.003), 60 min (1.49 ± 0.28 vs. 1.30 ± 0.22 kcal/min; p = 0.025), and 120 min (1.51 ± 0.26 vs. 1.33 ± 0.27 kcals/min; p = 0.014) post-ingestion. Meltdown significantly decreased RER at 30 min (0.84 ± 0.03 vs. 0.91 ± 0.04; p = 0.022) and 45 min post-ingestion (0.82 ± 0.04 vs. 0.89 ± 0.05; p = 0.042), and immediately post-exercise (0.83 ± 0.05 vs. 0.90 ± 0.07; p = 0.009). Furthermore, over the course of the evaluation period, area under the curve assessment demonstrated that REE was significantly increased with Meltdown compared to placebo (992.5 ± 133.1 vs. 895.1 ± 296.1 kcals; p = 0.043), while RER was significantly less than placebo (5.55 ± 0.61 vs. 5.89 ± 0.44; p = 0.002) following ingestion. HR and BP were not significantly affected prior to exercise with either supplement (p > 0.05) and the exercise-induced increases for HR and BP decreased into recovery and were not different between supplements (p > 0.05). These data suggest that Meltdown enhances REE and fat oxidation more than placebo for several hours after ingestion in fully rested and post-exercise states without any adverse hemodynamic responses associated with maximal exercise.


Journal of Medicinal Food | 2009

Cassia Cinnamon for the Attenuation of Glucose Intolerance and Insulin Resistance Resulting from Sleep Loss

J Jitomir; Darryn S. Willoughby

Epidemiological investigations reveal a concomitant increase in sleep loss and metabolic diseases, including type 2 diabetes mellitus, over the past several decades. An increasing body of scientific evidence indicates that acute sleep loss induces insulin resistance and glucose intolerance profiles similar to those of type 2 diabetes mellitus patients. Experimentally, cassia cinnamon (Cinnamomum cassia) supplementation facilitates glucose disposal in healthy humans, which may be achieved by enhancing (1) insulin sensitivity via increased phosphorylation of signaling proteins and (2) insulin-sensitive glucose transporter 4-mediated glucose uptake into muscle cells. Because peripheral insulin resistance is primarily a consequence of reduced muscle insulin sensitivity, C. cassia and C. cassia extracts may attenuate insulin resistance and glucose intolerance observed following sleep loss.


Journal of The International Society of Sports Nutrition | 2008

Anthrpometric changes of a female bodybuilder on a high-protein, hypocaloric diet

J Jitomir; Darryn S. Willoughby

Results Analysis of four day food records following each testing session revealed average values of 1588 ± 116.7 kcal/day, 43.6 ± 7.3% protein, 35 ± 5.4% carbohydrates, 17.8 ± 7.98% fat throughout the testing period. Additionally, the participant lost 6.09 kg (13.4lb) and 2.5 BMI units. Furthermore both HHBIA (.935; p = .006) and JP7 (.954; p = 0.003) were significantly and positively correlated to DEXA (CI = 99%). Finally, only HHBIA BF% values were statistically different from DEXA BF% values (p = .001).


Journal of The International Society of Sports Nutrition | 2008

VPX Meltdown® significantly increases energy expenditure and fat oxidation without affecting hemodynamic variables in a randomized, double-blind, cross-over clinical research trial

J Jitomir; E Nassar; Julie Culbertson; Jen Moreillon; Matthew B. Cooke; Thomas W. Buford; Geoffrey M. Hudson; Darryn S. Willoughby

Methods In a double-blind, placebo-controlled, cross-over design, participants underwent two testing sessions after consuming either the VPX Meltdown® or placebo supplement. Healthy male participants (n = 12) aged 18–35 rested for one hour while energy expenditure (EE), respiratory exchange ratio (RER), heart rate (HR), and blood pressure (B) were assessed in a fasted state. Subsequently, participants orally ingested either supplement or placebo. Immediately following supplement administration, participants rested for another hour while EE, RER, HP, and BP were recorded. Thereafter, participants performed a maximal exercise test on a treadmill and then endured another hour of EE, RER, HR, and BP measurement.


Journal of The International Society of Sports Nutrition | 2009

Effects of diet cycling during training on weight loss and resting energy expenditure: a preliminary analysis

Richard B. Kreider; J Jitomir; J Culbertson; M Byrd; S Simbo; C Curts; Monica C. Serra; Kristen M. Beavers; Jen Moreillon; Maria Pontes Ferreira; R Li; Brian Shelmadine; C Rasmussen; Mike Greenwood

Background Long-term dieting has been reported to reduce resting energy expenditure (REE) leading to weight regain once the diet has been curtailed. Diets are also difficult to follow for a significant length of time. The purpose of this preliminary proof of concept study was to examine the effects of short-term intermittent dieting during exercise training on REE and weight loss in overweight women.


The FASEB Journal | 2008

Effects of the Curves(R) fitness and weight loss program in senior-aged women: resting energy expenditure

Monica C. Serra; J Wismann; M Galbreath; R Chandran; Kristen M. Beavers; Geoffrey M. Hudson; R Li; J Jitomir; Brian Shelmadine; E Deike; E Nassar; A Parker; J Dove; Thomas W. Buford; Bill Campbell; P La Bounty; Matthew B. Cooke; C Rasmussen; Ronald L. Wilson; R Kreider


The FASEB Journal | 2009

Relationship of uric acid to body composition, heart disease risk factors and energy expenditure

Chad M. Kerksick; Kristen M. Beavers; R Chandran; J Jitomir; Monica C. Serra; Brian Shelmadine; Colin Wilborn; J Wismann; E Nassar; J Dove; M Galbreath; P La Bounty; Bill Campbell; Maria Pontes Ferreira; Matthew B. Cooke; M Iosia; C Rasmussen; Ronald L. Wilson; Richard B. Kreider

Collaboration


Dive into the J Jitomir's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Geoffrey M. Hudson

University of Southern Mississippi

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Bill Campbell

University of South Florida

View shared research outputs
Researchain Logo
Decentralizing Knowledge