Department of Health, Human Performance, and Recreation
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Browsing Department of Health, Human Performance, and Recreation by Author "Baylor University. Dept. of Health, Human Performance and Recreation."
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Item Acute effects of caloric intake and macronutrient type on body weight, body composition, resting energy expenditure, and total metabolic rate.(2006-07-31T01:12:44Z) Thomas, Ashli.; Kreider, Richard B., 1962-; Health, Human Performance and Recreation.; Baylor University. Dept. of Health, Human Performance and Recreation.Obesity is a growing epidemic with no consensus regarding solutions. Thirty healthy overweight and obese female subjects (41.9 ± 12 years, 166 cm ± 7 cm, a 100.5 kg ± 19.6 kg, 46.0% ± 4.0% body fat, and BMI 37.4 ± 6.9) participated in the study. A 14-day dietary intervention examined acute effects of energy balance and macronutrient type on dietary intake, REE, body weight, body composition, and thyroid panel. Significant changes occurred in weight loss over time (p < 0.001); body fat mass over time (p < 0.001) and time x diet (p = 0.02); body fat percentage over time (p < 0.002) and time x diet (p = 0.023); REE over time (p = 0.03), and thyroid panel. Body weight continued to decrease during positive energy balance, yet metabolism rebounded. Results suggest energy balance has a greater overall effect on REE and weight loss than macronutrient type.Item Acute effects of dynamic and static stretch on the peak torque and ROM of the shoulder internal and external rotators.(2010-10-08T16:28:04Z) Smart, Mary Megan.; Greenwood, Lori D.; Health, Human Performance and Recreation.; Baylor University. Dept. of Health, Human Performance and Recreation.Purpose: The primary purpose was to determine whether or not static and/or dynamic stretch techniques affect the peak torque and average power of the shoulder rotators. A secondary purpose was to assess and compare range of motion after the two stretching techniques. Methods: Using a cross-over design, 16 recreationally active females (18-35 yrs) participated in three sessions (baseline, static stretch, dynamic stretch) separated by at least 48 hours. Each subject warmed-up for five minutes before being tested for peak torque and power measurements, using Biodex System 3 Isokinetic dynamometer with 5 repetitions at 60°/second and 180°/second, and range of motion with a standard universal goniometer was also measured. In sessions two and three, the participant performed either 3x15 repetitions of five dynamic stretches or 3x25 second holds of five static stretches between warm-up and testing. Subjects were randomized as to the order of stretch sessions. Results: No significant differences were found between stretch protocols.Item The acute effects of Pterocarpus Marsupium supplementation on insulin-dependent and insulin-independent signaling pathways at rest, after an oral glucose tolerance test and after intense exercise in overweight pre-diabetic females.(2010-06-23T12:25:24Z) Shelmadine, Brian.; Cooke, Matthew B.; Willoughby, Darryn Scott, 1963-; Health, Human Performance and Recreation.; Baylor University. Dept. of Health, Human Performance and Recreation.Increasing physical activity and modifying diet to incorporate more phytonutrients has been suggested as a way to prevent the progression of insulin resistance (IR) into cardiometabolic disease. Pterocarpus Marsupium (PM), a phytonutrient compound shown to improve hyperglycemia, could potentially improve IR. The primary purpose of this study was to examine the effects of PM on insulin sensitivity and blood lipids in overweight and obese, sedentary women classified as prediabetic. Further, to examine the effects of acute ingestion of PM on insulin- and exercise-mediated glucose disposal following an oral glucose tolerance test (OGTT) and aerobic exercise bout, and to understand the mechanisms by which PM supplementation may affect specific muscle gene expression. A double-blind, randomized, placebo controlled study was conducted. Participants consumed 250 mg of either PM (n=8) or placebo (PL, n=8) twice daily for 6 days. Blood and muscle samples were obtained prior to supplementation, prior to and following OGTT, and prior to and following an exercise bout. Following OGTT, plasma glucose levels were higher at 30 minutes (p<0.001) and 1 hour post-OGTT (p=0.001) in both PM and PL groups. Similarly, plasma insulin levels were higher 30 minutes (p=0.023), 1 hour (p=0.023), and 2 hours post-OGTT (p=0.003) in both PM and PL groups. Additionally, serum glucose levels decreased from 30 minutes to 1 hour postexercise (p = 0.011), and from 30 minutes to 2 hours postexercise (p = 0.013) in both PM and PL groups. A significant increase in mRNA expression of Akt2 (p = 0.001), AMPK (p = 0.001), AS160 (p = 0.02), and PPARα (p = 0.025) was observed one hour after OGTT. The findings suggest that 250 mg of PM twice daily does not improve insulin sensitivity or fasting lipid levels in this population. However, this is the first study to report the novel finding of an increase in skeletal muscle mRNA expression of Akt2, AMPK, AS160, and PPARα in response to an OGTT. The observed increase, and subsequent decrease, in serum glucose levels after brief, maximal exertion exercise was also novel.Item Analysis of exercise intensity and energy expenditure of women participating in the Curves exercise program.(2006-07-30T19:49:16Z) Farris, Gregory D.; Kreider, Richard B., 1962-; Health, Human Performance and Recreation.; Baylor University. Dept. of Health, Human Performance and Recreation.The Curves program is designed to improve fitness. The purpose of this study was to identify exercise intensity, HR and energy expenditure in a group of women participating in the Curves program. Seventy-eight women (53.6 ± 7.09 yrs, 192.1 ± 30.43 pounds, 43.5 ± 4.52 % fat) performed the Curves workout on two occasions. Results show that mean HR was 119 ± 15 b/min which was equivalent to 79% max HR or 63 % HRR. Thirty-three women (52.7 ± 6.68 yrs, 193.1 ± 31.73 pounds, 1.8 ± 0.28 L/min VO2 max) performed the Curves 30-min workout on two occasions. Results show that the mean RER to perform the 30-min workout was 1.00 ± 0.07 and 0.98 ± 0.05 for the two sessions. Estimated caloric expenditure was 164.5 ± 25.19 kcals and 160.6 ± 28.36 kcals for the two sessions. Results indicate that the Curves program qualifies as moderate intensity exercise.Item An analysis of the strength of religious faith of student-athletes and non-student-athletes at NCAA Division I-FBS institutions.(2014-01-28) Evans, Jonathan W. (Jonathan Worrell), 1977-; Petersen, Jeffrey C. (Jeffrey Christian); Health, Human Performance and Recreation.; Baylor University. Dept. of Health, Human Performance and Recreation.This study evaluated and compared the religiosity of student-athletes and non- student-athletes at faith-based and non-faith-based NCAA Division I-FBS institutions via a modified version of the Santa Clara Strength of Religious Faith Questionnaire. A comparison of religiosity between institutions, gender, and student-athlete status was made as well as an exploration of the relationship between religiosity of these students and their intentions to use alcohol, tobacco, or performance enhancing drugs from a representative sample from two institutions (N = 613). Results from a 2 x 2 x 2 ANOVA found significant differences in religiosity based on gender, but no significant differences in religiosity by institution. The student-athletes at the non-faith-based institution were significantly more religious than the non-student-athletes. Logistic regression revealed students at the faith-based school were more likely to agree their faith impacted decisions regarding college choice, academic/athletic performance, alcohol, tobacco, and performance-enhancing drug use than those from the non-faith- based school.Item The church and obesity today : the role of the church in promoting physical activity among south Texas Hispanic populations.(2013-09-16) Salazar, Cindy Lynn.; Umstattd Meyer, M. Renée.; Health, Human Performance and Recreation.; Baylor University. Dept. of Health, Human Performance and Recreation.The purpose of this study was to determine what physical activity resources are provided by churches within south Texas Hispanic communities and to determine if the Physical Activity Resource Assessment (PARA) instrument is valid when adapted for online assessments. Churches were identified within four cities of the Lower Rio Grande Valley and physical activity resources on the churches’ property were surveyed through Google Maps using the PARA instrument (n=195). The most often identified physical activity resources included basketball courts, soccer fields, play equipment, sidewalks, open fields, and fenced-in open fields. In-person PARA assessments were also conducted for 30 churches. Percent agreement and Spearman correlation coefficient calculations between in-person and Google assessments for these 30 churches suggest the PARA is suitable for online use. Churches within Hispanic communities may potentially serve as a viable resource by which to promote physical activity among Hispanic populations. Further research should be conducted to survey internal resources and programming of churches.Item Comparison of post-exercise recovery strategies on physiological and biochemical markers of exercise-induced muscle damage.(2010-10-08T16:24:44Z) Nix, Carrie M.; Cooke, Matthew B.; Health, Human Performance and Recreation.; Baylor University. Dept. of Health, Human Performance and Recreation.From the elite competitor, to the weekend athlete, or as a result of everyday activities, muscle injuries are a way of life. To date, no studies have examined the effectiveness of the Alter-G G-Trainer to enhance muscle recovery from injury. Twenty-five recreationally active males between 18 and 35 were randomly assigned to one of three recovery groups: G-Trainer, treadmill running, static stretching. Recovery was performed 30 minutes, 24, 48, and 72 hours following a 45 minute downhill run. Isokinetic strength, creatine kinase, superoxide dismutase, malondialdehyde, muscle soreness and mood states were assessed at baseline, 15 minutes, 3, 24, 48, 72, and 96 hours post-exercise. Significant time effects were observed for isokinetic knee flexion/extension at 60 and 180°/second, muscle soreness (p<0.05), muscle soreness (p<0.001) and POMS (p=0.013). A significant group by time interaction (p=0.027) was observed for POMS. The G-Trainer treadmill was unable to enhance muscle recovery following exercise-induced muscle damage.Item Comparison of the effects of aquatic and land-based balance training programs on the proprioception of college-aged recreational athletes.(2010-10-08T16:28:44Z) Spiers, Shellie.; Greenwood, Lori D.; Health, Human Performance and Recreation.; Baylor University. Dept. of Health, Human Performance and Recreation.Purpose: To determine if aquatic and land-based balance training programs created significantly different improvements in levels of balance ability measured among college-aged recreational athletes. Methods: 18 active males and females, ages 18 – 35, were randomly assigned to an aquatic or land-based training group. Following baseline testing for various measures of postural control using the Limits of Stability, Unilateral Stance, and Sensory Organization Test protocols, the intervention groups performed a preset program of balance exercises three days a week for six weeks. Balance ability was then reassessed using the three test batteries to determine if any differences existed. Statistical analysis: A 2 (group) x 2 (pre-test,post-test) mixed analysis of variance was performed to determine statistical significance. Results: No significant differences were found between groups among any measures of balance ability.Item Determining related work-to-rest ratios following a maximal effort isokinetic leg extension bout in trained and untrained males : a double-blind creatine/placebo controlled study.(2010-02-02T20:02:01Z) Parker, Adam G.; Greenwood, Mike.; Health, Human Performance and Recreation.; Baylor University. Dept. of Health, Human Performance and Recreation.Purpose: A single 30 second bout of high intensity isokinetic exercise is capable of depleting available skeletal muscle Phosphocreatine (PCr) and adenosine triphosphate (ATP). Within several minutes the body is able to replenish those stores to facilitate further muscular activity. There have been suggested work-to-rest ratios to allow for the optimal recovery period to achieve repletion of the intramuscular PCr and ATP. This study attempted to determine how training status and supplementation with creatine monohydrate (CM) may affect this process. Methods: Subjects in the CM group consumed 20 g of CM (four 5 g doses/day), while subjects in the placebo group consumed 20 g of dextrose (four 5 g doses/day). Five (pre-supplementation, pre-exercise, immediate post exercise, 3 min. post exercise, and 5 min. post exercise) muscle samples were taken from the vastus lateralis of the dominant leg of 32 males [16 resistance trained (8 each receiving CM or placebo), 16 untrained (8 each receiving CM or placebo)]. Samples were measured for Cr, PCr, ATP, glycogen, and lactate, and TCr was calculated by adding Cr and PCr at all time points. Blood lactate was measured via finger prick prior to and 5 minutes after the exercise bout. Results: Subjects consuming CM increased muscle total creatine content by 10.2%. Neither CM supplementation nor resistance training status significantly affected PCr or ATP repletion rates. Trained subjects had significantly (p >.05) higher muscle glycogen content. Trained individuals maintained non-significantly higher muscle ATP and PCr after and at all time points during recovery from the exercise bout compared to untrained individuals. At both 3 and 5 minutes after exercise, none of the groups were able to fully restore resting levels of muscle ATP or PCr. Conclusions: The results indicate that CM and training status did not significantly enhance repletion rates of muscle ATP or PCr. Further, 5 minutes of rest was not long enough to fully recover muscular ATP and PCr content.Item The effect of exercise intensity on postprandial blood lipids.(2014-01-28) Littlefield, Laurel A.; Grandjean, Peter W.; Health, Human Performance and Recreation.; Baylor University. Dept. of Health, Human Performance and Recreation.The purpose of the present investigation was to determine the effects of exercise intensity on the blood lipid response to a high-fat test meal in sedentary, overweight men, and to determine the contribution of excess post-exercise oxygen consumption (EPOC) to changes in postprandial lipemia. Seven men (Age = 43 ± 10 years; BMI = 31.8 ± 4.5 kg/m²; Waist = 107.2 ± 14.9 cm; and VO₂peak = 31.7 ± 7.5 ml/kg/min) participated in 4 experimental conditions: control, low-intensity (LI = 40-50% of VO₂ reserve), high-intensity (HI = 70-80% of VO₂ reserve), and HI exercise plus EPOC re-feeding (HI + EERM) where the difference in EPOC following LI and HI was re-fed in the form of a meal bar (Peanut Butter PowerBar ®). Exercise sessions were isocaloric (500 calories) and completed in the morning after a 12-hour overnight fast. Blood samples were taken before and after exercise, immediately before, and 2, 4, and 6 hours after a high-fat test meal (1010 calories, 100 g fat, 99 g saturated fat, 17 g carbohydrate, 3 g protein). Serum samples were measured for triglycerides (TG), lipoprotein cholesterol, non-esterified fatty acids (NEFA), glucose and insulin and were analyzed using 2-way repeated-measures ANOVAs. Repeated measures ANOVAs were used to examine triglyceride and insulin total (AUCT) and incremental (AUCI) areas under the curve. Comparisonwise significance was set at p < 0.05. Compared to control, TG were lower at 4 hours after both exercise intensities and remained lower at 6 hours after LI only. LI and HI significantly reduced postprandial triglyceride AUCI by 31 and 27%. AUCI and AUCT were similar between exercise intensities and changes in other dependent variables were of similar magnitude and direction in all conditions. The lower postprandial TG observed after exercise was not diminished in the HI+EERM trial. The results of this study indicate that similar significant reductions in postprandial triglycerides occur with LI and HI exercise with and without replacement of EPOC calories. In sedentary overweight men, EPOC does not contribute substantially to energy expenditure or reductions in postprandial lipemia.Item Effects of 28 days of protein and amino acid supplementation and ankle immobilization on gastrocnemius muscle mass and strength and atrophy- and apoptosis-related gene expression in males.(2008-06-11T11:43:18Z) Wismann, Jennifer.; Willoughby, Darryn Scott, 1963-; Health, Human Performance and Recreation.; Baylor University. Dept. of Health, Human Performance and Recreation.Purpose: The primary purpose was to determine the extent to which the daily supplementation of protein and amino acids for 28-days in combination with ankle immobilization in humans attenuated decreases in: 1) gastrocnemius muscle mass, 2) plantar flexion strength, 3) and expression of genes associated with the ubiquitin proteolytic pathway (UPS) and calcium-activated proteolytic system (CAS). A secondary purpose was to assess the safety of 28-days of protein and amino acid ingestion by evaluating whole blood and serum clinical chemistry markers. Methods: Twenty male participants wore a lower-limb immobilization boot for 28 days, consumed either a protein and amino acid supplement or an isocaloric carbohydrate placebo twice daily, and underwent testing at days 0, 14, and 28. Each testing session included hemodynamic measurements, blood collection, body composition analysis, lower leg girth and skinfold measurement, strength measurement, dietary analysis, and gastrocnemius muscle biopsies. The muscle tissue was analyzed for mRNA expression of ubiquitin, 20S-HC2, 20S-HC3, E2, E3, atrogin-1, MuRF1, calpain 1, calpain 2, myostatin, TNF-α, and NF-κB. Results: Lower-leg girth decreased over time (p = 0.020), and increased the expression of several genetic variables, but there were no significant changes in the body composition or strength variables (p > 0.05). All UPS, CAS, cytokine, and myostatin degenerative markers showed a significant increase over time (p < 0.05). However, significant interactions only occurred for E2 (time x group, p < 0.001) and E3 (time x group x leg, p > 0.016). Conclusion: The study showed no difference between groups for any of the genetic proeolytic markers, but indicated that several of these markers were increased in the immobilized and control legs. These changes may indicate a link between the UPS and TNF-α and NF-κB. Additionally, the results also indicated that myosatin may play a role in muscle astrophy induced by immobilization, instead of only disease and fasting.Item The effects of a 12-week resistance training program combined with casein or whey protein supplementation on body composition, muscle strength, and markers of satellite cell activation in older males.(2010-10-08T16:12:13Z) Allison, Annie G.; Cooke, Matthew B.; Health, Human Performance and Recreation.; Baylor University. Dept. of Health, Human Performance and Recreation.Resistance training and protein supplementation have been shown to increase muscle mass and strength, and thus may be an effective method to combat muscle wasting (sarcopenia) that occurs with aging. Thirty-six males (62.5 yrs, 177 cm and 95.25 kg) were randomly assigned to ingest either whey isolate protein, casein protein or carbohydrate while participating in a 12-week high intensity resistance training program. Resistance training increased both upper and lower body strength, body mass and lean muscle mass while decreasing body fat percentage. However, no effects from training were observed on serum anabolic hormones and indirect markers of satellite cell activation. A trend towards significantly higher lower body strength was observed in the whey isolate (p=0.053) and casein (p=0.086) groups, respectively, compared to carbohydrate placebo group. The present study suggests protein supplementation in conjunction with high intensity resistance training may be important in combating sarcopenia.Item Effects of a high protein diet on weight loss, markers of health, and functional capacity in senior-aged females participating in the Curves® fitness program.(2008-12-01T16:42:21Z) Galbreath, Melyn.; Kreider, Richard B., 1962-; Health, Human Performance and Recreation.; Baylor University. Dept. of Health, Human Performance and Recreation.Purpose: To determine the effectiveness of elderly females aged 60-75 years following the Curves fitness and weight loss program on body composition, markers of health, and functional capacity. Methods: 55 senior aged overweight females (66 ± 5 years; 79 ± 11 kg) were randomly assigned to one of three groups: High Protein diet + Exercise (HP); High Carbohydrate diet + Exercise (NCHO); or Exercise only (E). Participants were instructed to follow their respective nutrition plans and complete a supervised 30 minute Curves circuit resistance-training program three times a week. The participants underwent an array of tests at 0, 10 and 14 weeks. An analysis of variance (ANOVA) for repeated measures was used to analyze the data. Results: Subjects in the HP experiencing significantly greater weight loss (HP -4.8 ± 3.2%, NCHO -3.0 ± 2.9%, E -1.1 ± 2.3%, p=0.001), fat mass (HP -10.2 ± 5.9%, NCHO -5.7 ± 4.0% and E -2.7 ± 3.9%, p=0.001), and percent body fat (HP -6.3 ± 3.5%, NCHO -3.8 ± 3.4%, and E only -2.2 ± 3.6%). Improvements were also noted in an appetite regulating hormones leptin (HP -42.1 ± 21.3%, NCHO 43.4 ± 56.1% and E .80 ± 35.1%, p=0.000). No significant changes were observed in fat free mass or resting energy expenditure. All groups experienced improvements in strength, muscular endurance, aerobic capacity, and a number of markers of health. Summary: The Curves exercise and weight loss program is effective in senior aged females in promoting weight loss and favorable body composition changes. The greatest effects were seen in the HP group.Item Effects of a multicomponent school-based intervention on health markers, body composition, physical fitness, and psychological measures in overweight and obese adolescent females.(2008-11-18T21:52:10Z) Dove, Jacqueline Beckham.; Kreider, Richard B., 1962-; Health, Human Performance and Recreation.; Baylor University. Dept. of Health, Human Performance and Recreation.The purpose of this study was to determine whether participation in a multicomponent school-based intervention using circuit-resistance training, dietary intervention and behavioral modification had an effect on health markers, body composition, physical fitness, and psychological measures for overweight/obese adolescent females. Forty-two overweight/obese adolescents participated in the 10-week program with assessments completed at 0, 10, and 22 weeks. Data were analyzed by ANOVA repeated measures analysis, with a level of significance set at p < 0.05, and presented as means ± SD from baseline. Statistically significant group x time interactions were observed for the following: body mass (CON 2.82% ± 2.7 vs. EXP 0.58% ± 2.5, p = 0.021) fat mass (CON 3.64% ± 5.9 vs. EXP -2.66% ± 5.7, p = 0.006), percent fat (CON 0.52% ± 4.69 vs. EXP -2.92% ± 4.44, p = 0.024), triglycerides (CON 44.78% ± 85.11 vs. EXP -9.56% ± 34.99, p = 0.002), HOMA-IR (CON 49.41% ± 69.65 vs. EXP 17.64% ± 66.76, p = 0.052), physical activity environmental factors (CON -6.92% ± 18.66 vs. EXP 9.96% ± 27.79, p = 0.039), fruit and vegetable con decisions (CON 31.71% ± 49.75 vs. EXP 3.41% ± 47.22, p = 0.043), and dietary protein intake (CON -3.28% ± 53.05 vs. EXP 8.15% ± 58.68, p = 0.025). Time significance represented an overall mean increase in body mass (1.6 % ± 3), lean mass (2.7% ± 4), bone mineral content (3.6% ± 5) and bone mineral density (3.4% ± 3). Follow-up testing was conducted with a subset of participants (n = 29), after three months. The participants’ revealed statistically significant group x time effects for the pediatric quality of life psychosocial health summary score (CON -23% ± 40 vs. EXP 25.3% ± 65, p = 0.039) and the PACE measurements of physical activity family support (CON -0.64% ± 24.4 vs. EXP 17.8% ± 19.3, p = 0.027). This research indicated that overweight/obese adolescent females can benefit from both standard physical education and a multicomponent program. However, the participants in the multicomponent program observed significantly greater improvements in body composition, triglycerides, and insulin sensitivity.Item The effects of active and passive recovery on blood lactate in collegiate female tennis players.(2007-03-08T15:33:24Z) Coffer, Larry W.; Greenwood, Mike.; Health, Human Performance and Recreation.; Baylor University. Dept. of Health, Human Performance and Recreation.Purpose: To examine the effects of active and passive recovery on lactate in females and to determine if a relationship exists between power and blood lactate concentration. Methods: Nine (9) female athletes performed two Wingate Power Tests. One test ended with passive recovery, the other ended with active recovery. Lactate was drawn during the recovery periods. From the Wingate Test, power indices were obtained. A t-test and an ANOVA were performed to evaluate differences in active and passive recovery and Pearson’s correlations were used to examine relationships between power and lactate values. Results: Active recovery significantly (p< 0.03) increased lactate removal compared to passive recovery. There were no significant correlations between lactate and power measures. Conclusions: Active recovery increases the rate of lactate removal in females; however, lactate measures are not correlated to the power measures from the Wingate Test.Item Effects of arachidonic acid supplementation on training adaptations in resistance-trained males.(2007-02-09T22:16:18Z) Roberts, Michael D.; Kreider, Richard B., 1962-; Health, Human Performance and Recreation.; Baylor University. Dept. of Health, Human Performance and Recreation.The purpose of this study was to determine if 50 days of resistance training and arachidonic acid (AA) supplementation elicited changes in body composition, performance variables, hormonal/cytokine levels (i.e. prostaglandins, free and total testosterone, cortisol, and interleukin-6) and/or intramuscular markers [i.e. myosin heavy chain (MHC) I, -IIa, -IIx mRNA and protein levels] in resistance-trained males. Thirty-one subjects (22.1±5.0 yrs, 86.1±13.0 kg, 178.9±3.4 cm, 18.1±6.4 % body fat) were randomly assigned to a placebo (P: n=16; 1 g corn oil/day) or AA group (AA: n=15; 1 g AA/day) and were given supplemental protein in order attain an optimal protein intake of 2 g/kg/day while participating in a 2 d/wk upper body and 2 d/wk lower body resistance training regimen. Body composition, bench press one-repetition maximum (1-RM), leg press 1-RM and Wingate bike sprint tests were completed at 0, 25 and 50 days. Fasting blood was taken on days 0, 25, and 50 and muscle biopsies were taken from the vastus lateralis on days 0 and 50. Body composition, performance variables, hormonal levels and MHC mRNA and protein concentrations were analyzed by ANOVA with repeated measures while independent t-tests were used to assess changes in MHC mRNA expression. A significant increase was observed in Wingate relative peak power in the AA group (p=0.015). Statistical trends were found for PGE2 increases (p=0.06) and IL-6 decrements (p=0.07) in the AA group and a significant decrement in percent changes in MHC IIx mRNA expression was present in the AA group (p=0.015). Results suggest that AA supplementation in trained males may exert favorable alterations in training adaptations and fasting prostaglandin and IL-6 levels. However, additional research is needed to examine this hypothesis.Item Effects of concentric and eccentric muscle contractions on IL-6 signaling in human skeletal muscle and downstream regulation of HSP-72 gene expression : Is IL-6 signaling involved in exercise-induced cytoprotection?(2009-04-01T16:08:10Z) Harvey, Travis.; Willoughby, Darryn Scott, 1963-; Health, Human Performance and Recreation.; Baylor University. Dept. of Health, Human Performance and Recreation.Purpose: To determine the effects of concentric and eccentric muscle contractions on IL-6 signaling and its possible downstream regulation of HSP-72 expression in human skeletal muscle, and whether contraction-induced IL-6 expression may initiate a cytoprotective mechanism in the muscle by activating HSP-72 and HSP-27. Methods: Using a cross-over design, 10 recreationally active males (20.60 ± 2.80 yrs; 77.35 ± 12.79 kg) participated in 2 separate bouts of 10 sets of 10 unilateral isokinetic knee extensions at 30°/sec. Each subject performed one concentric (CON) and one eccentric (ECC) bout, with strength assessed 5 days prior to and at 24 and 48 hr after the bout. Muscle soreness and blood samples were sampled immediately before exercise (PRE), immediately post-exercise (POST), and at 2, 6, 24, and 48 hr after exercise for serum levels of CK, IL-6, IL-1β, and TNF-α. Muscle biopsies were obtained at PRE, POST, and at 2 and 6 hr post-exercise and assessed for protein levels of IL-6, HSP-72, HSP-27, NF-кB, p38 MAPK, STAT-1, and STAT-3 and for mRNA expression of IL-6, HSP-72, and HSP-27. Repeated measures MANOVA for isokinetic peak torque revealed a significant decrease in strength at 24 and 48 hr post-exercise. Repeated measures MANOVA on muscle soreness and CK located a significant (p ≤ 0.05) main effect for time for both variables, but not for contraction type. Repeated measures MANOVA for cytokine serum variables demonstrated no significant results. Repeated measures MANOVA for muscle variables demonstrated no significant main effect for contraction, though a significant main effect for time was located. Pairwise comparisons demonstrated a significant difference from immediately post-exercise to 6 hr post-exercise for HSP-27. Gene expression of muscle variables demonstrated no significant results. Conclusion: The CON and ECC bouts demonstrated muscle damage through significant elevations in CK and muscle fatigue through significantly decreased torque production at 24 and 48 hr post-exercise. However, the damage induced during the acute bouts appears to have been insufficient to produce systemic and intramuscular signaling of the IL-6 pathway and its associated factors. Further human research still needs to be conducted on this pathway with the factors investigated here, though other exercise intensities and modes should be considered.Item The effects of creatine ethyl ester supplementation combined with resistance training on body composition, muscle mass and performance, and intramuscular creatine uptake in males.(2008-12-01T16:56:29Z) Spillane, Micheil Brian (Mike).; Willoughby, Darryn Scott, 1963-; Health, Human Performance and Recreation.; Baylor University. Dept. of Health, Human Performance and Recreation.Creatine monohydrate has become one of the most popular ingested nutritional supplements due to its potential enhancement of athletic performance. Creatine absorption from the serum into skeletal muscle occurs through the utilization of a membrane-spanning protein, CreaT1. Numerous creatine formulations have been developed primarily to maximize creatine absorption. Creatine ethyl ester (CEE) has been chemically modified by adding an ester group and is thought to increase creatine bio-availability by by-passing the CreaT1. This study examined how a seven week supplementation regimen with CEE affected body composition, muscle mass and performance, whole body creatine retention, as well physiological and molecular adaptations, associated with creatine uptake in nonresistance-trained males following a resistance-training program. Results demonstrated that CEE did not show any additional benefit to increases in muscle strength/performance or a significant increase in total muscle creatine when compared to creatine monohydrate or placebo. CEE supplementation did show a large increase in creatinine levels throughout the study.Item The effects of creatine monohydrate supplementation on creatine transporter activity and creatine metabolism in resistance trained males.(2008-10-15T14:27:54Z) Moulton, Christopher J.; Willoughby, Darryn Scott, 1963-; Health, Human Performance and Recreation.; Baylor University. Dept. of Health, Human Performance and Recreation.Creatine is a nutritional supplement that is used for its potential performance enhancing (ergogenic) benefits. It constitutes an important component of the immediate energy system, by which ATP is regenerated during intense physical activity. Oral creatine supplementation has been shown to provide numerous benefits, including increases in lean muscle mass, muscular strength, and enhanced performance in various athletic capacities. The creatine transporter is a transmembrane protein that mediates the entry of creatine from the circulation into the muscle cell. Little is understood about the importance of the creatine transporter in controlling the uptake and regulation of creatine within human skeletal muscle. This study attempts to characterize the specific variations in creatine receptor activity and concurrent creatine metabolism in human skeletal muscle in response to a regimen of oral creatine supplementation including a one week loading phase, a four week maintenance phase, and a four week washout phase. Supplementation induced significant increments in total body mass (p = 0.03) and lean body mass (p = 0.01). A moderate effect size (d = 0.51) was found for strength increase, which suggests that the study was underpowered to detect a significant difference in strength increase. There appeared to be no effect of supplementation on intramuscular creatine; however, these data were subject to large measurement error and are not likely accurate. There was no apparent effect on creatine transporter mRNA or creatine transporter content when measured after the loading phase, during and after the maintenance phase, and after the washout phase.Item Effects of eight weeks of 6-OXO supplementation on serum hormone profiles and on serum and urinary clinical safety markers in resistance-trained males.(2006-05-28T23:31:42Z) Rohle, Daniel A.; Willoughby, Darryn Scott, 1963-; Health, Human Performance and Recreation.; Baylor University. Dept. of Health, Human Performance and Recreation.The purpose of this study was to determine the effects of 6-OXO, an aromatase inhibitor, in a dose dependent manner on serum hormone levels and clinical safety markers in resistance trained males. Sixteen healthy trained subjects, who participated in a resistance training protocol, had blood samples taken at weeks 0, 1, 3, 8, and 11. These samples were analyzed for total testosterone, free testosterone, DHT, estradiol, estriol, estrone, SHBG, LH, FSH, GH, and cortisol. There were no significant differences between groups (p>0.01). However, total testosterone concentration, free testosterone concentration, and DHT concentration increased over the course of the study (p=0.009). Measures of body composition did not change with supplementation (p>0.05). Safety markers were seen to not be adversely affected with ingestion of 6-OXO (p>0.01). 6-OXO supplementation appears to be safe and increases total testosterone, free testosterone, and DHT concentrations independent of the two different doses.
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