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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
181

The effects of pre-exercise carbohydrate supplementation on anaerobic exercise performance in adolescent males

Lee, Jonah D. January 2007 (has links)
This study examined the effects of pre-exercise carbohydrate (CHO) supplementation on anaerobic exercise performance in adolescent males (n =11; 15.0 ± 0.9 yrs). On separate days, subjects consumed either a CHO or a placebo (PL) beverage followed by 2 Wingate anaerobic tests (WAnT) separated with ten by 10-second sprints. Peak (PP), mean power (MP) and fatigue index (FI) were assessed. Venous blood samples were obtained and analyzed for glucose, lactate, insulin, and catecholamines. A trial by time ANOVA (P < 0.05) was used in the analysis. PP and MP tended to be higher (P < 0.09) in CHO versus PL, and MP tended to decline more in CHO (P < 0.06); Fl for the two WAnT were similar. Glucose concentration significantly increased after CHO consumption and then returned to baseline post-exercise, whereas glucose level remained unchanged over time during PL; similarly observed for insulin. Lactate and catecholamine levels significantly increased over time, but a trial difference was only observed in epinephrine. The tendency for PP and MP to be higher in CHO might suggest a potential ergogenic benefit of pre-exercise CHO although the change in MP over time in CHO and the similarity in Fl might suggest otherwise. / School of Physical Education, Sport, and Exercise Science
182

The metabolic response to acute exercise in adolescent boys with NIDDM relatives

Hanna, Lauren E. January 2008 (has links)
Individuals with NIDDM and low insulin sensitivity (Si) have altered fuel use, which may appear in NIDDM relatives. Adolescent males, six with NIDDM relatives (POS) and six controls (CON), matched for fitness and fatness, participated. Peak oxygen uptake (V02pea), ventilatory threshold (VT) and body composition were measured. Insulin and glucose values were used for Si estimates. Oxygen consumption (V02) and respiratory exchange ratio (RER) measurements were made at rest and during exercise at 80,100 and 120% of VT for substrate use. No group differences were found in anthropometric data, V02pea, VT or blood measurements, although fat free mass (FFM) tended to be greater in CON. CON tended to use a higher percentage carbohydrate and a lower percentage of fat than POS, but differences were no longer present after normalization to FFM. Trends towards fuel use differences may suggest metabolic abnormalities are present in POS, but further investigation is necessary. / School of Physical Education, Sport, and Exercise Science
183

Heart rate recovery and heart rate variability during recovery from submaximal and maximal exercise in boys and men / Title on signature form: Heart rate recovery and heart rate variability following maximal and submaximal exercise in boys and men

Guilkey, Justin P. 23 May 2012 (has links)
This study investigated differences in heart rate recovery (HRR) and the underlying autonomic mechanisms following maximal and submaximal exercise between boys and men. Children are known to have a faster HRR than adults. However, the mechanism responsible for these differences is still largely unknown, but is thought to be due to differences in the autonomic nervous system. Ten boys (10.1 ± 0.8 years old) and ten men (24.2 ± 1.3 years old) completed a supine recovery following a maximal and submaximal exercise bout. HRR was measured as the decline in HR during the first minute of recovery and heart rate variability (HRV) was used to measure autonomic function. Boys had a faster HRR during the first minute of recovery from maximal exercise (p<0.05), but there was no difference in HRR following submaximal exercise (p>0.05). The R-R coefficient of variation and high frequency power were both significantly greater following maximal exercise in boys than men. There were no differences in HRV variables following submaximal exercise. These findings suggest that faster parasympathetic re-activation could be a mechanism responsible for faster HRR in boys compared to men, especially following maximal exercise. / School of Physical Education, Sport, and Exercise Science
184

Fluid replacement after exercise in the heat : influence of beverage carbonation and carbohydrate content

Lambert, Charles Paul January 1990 (has links)
This investigation evaluated the Influence of beverage carbonation and carbohydrate content on fluid replacement following exercise/thermal dehydration. Eight recreationally trained men cycled at 50% of their maximal aerobic power in a hot environment (40°C 40% relative humidity) until a body weight loss of 4.12 ± 0.02% was attained. In the subsequent four hours subjects ingested one of four randomly assigned solutions at 15 minute intervals. The total volume ingested equalled that lost during dehydration. The solutions varied in their carbohydrate and carbonation content as follows: 1) CK: carbonated 10% carbohydrate solution, 2) NCK: non-carbonated 10% carbohydrate solution, 3) CNK: carbonated non-caloric solution, and 4) NCNK: non-carbonated non-caloric solution. Before dehydration and at 0, 60, 120, 180, and 240 minutes of recovery subjects performed a five minute cycling bout (SCB) at 70% venous blood samples were obtained before and after dehydration, and at 30, 90, 150, and 240 minutes of of their maximal aerobic power. In addition, resting data from the carbohydrate treatments were pooled and recovery. Rehydration evaluated from body weight, plasma volume, plasma protein, and urine volume data was not significantly (p> 0.05) different between treatments at any time. In addition, carbonated beverage (CK and CNK) ingestion did not significantly alter the pC02 or pH of venous blood at rest or the respiratory exchange ratio (RER) during exercise, however, the ingestion of carbohydrate beverages (CK and NCK) elevated the RER during the SCB relative to the level elicited by Ingestion of non-carbohydrate beverages. Oxygen consumption during the SCB at 240 minutes was significantly (p< 0.05) higher in the non-carbohydrate treatments (NCNK vs. CK and CNK and NCNK vs. NCK), however, no differences in caloric expenditure were observed. Arterialized blood lactate one minute after each SCB was not different between treatments. Lactate levels were significantly higher, however, when compared to the non-carbohydrate treatments. No significant differences were observed in ratings of perceived exertion, or ratings of gastrointestinal comfort. The results of this Investigation suggest that solutions which are carbonated and/or contain a carbohydrate concentration of 10 b are as effective as non-carbonated and/or non-carbohydrate solutions with regard to fluid replacement. In addition, the ingestion of carbonated beverages does not appear to be associated with alterations in the pC02 or pH of venous blood or gastric distress relative to the levels attained with non-carbonated beverages. / School of Physical Education
185

Effect of sodium and water intake on plasma aldosterone during prolonged exercise in warm environment

Shi, Xiaocai January 1990 (has links)
Eight well-trained male and female cyclists were studied to determine the effect of sodium and/or water intake on plasma aldosterone during six hours of cycling (55% VO2max) in a warm environment (Tdb = 350C WBGT = 30°C). Each subject randomly completed three trials (water = W; saline = S and no fluid = NF) at one week intervals. Venous blood samples were obtained before dehydration, at 2, 4, 5 and 6 hours during exercise, and also after dehydration. Plasma samples were analyzed for hemoglobin, sodium, potassium, aldosterone and osmolality. Sweat and urine samples were also collected and analyzed for sodium content. Plasma volume based on hemoglobin decreased significantly ( P < 0.01 ) at 15 min in all three trials (Trial W = -7.6%±1.12%; Trial S = -8.6%±1.42% and Trial NF = -6.7%±0.88%) and continued to decrease significantly in Trial NF during exercise ( -10.99% ± 1.3% at the 2th hr; -15.5% ±1.3% at the 4th hr and -16.8%±1.32% at the 5th hr).No significant differences were found betwee trials. Plasma sodium concentration [Na+] decreased over time in Trials W and S and increased in Trial NF due to plasma volume loss. Significant differences in [ Na+ ] were found between Trial NF and Trials W or S. Plasma sodium [Na+ ] adjusted by plasma volume change decreased significantly at 2 hours ( P < 0.01) in the three trials. Average total sodium content of plasma decreased by 125.9 mEq during Trial S, 223.1 mEq during Trial W and 147.1 mEq during Trial NF. Plasma potassium increased significantly (P < 0.01) at 2 hours in all three trials. Plasma osmolality increased significantly (P < 0.01) during prolonged exercise (Trial W = 287.1±2.4 mEq/l; Trial S = 289.4±1.17 mEq/1 and Trial NF = 306±1.6 mEq/1). No significant differences were found between Trials W and S although osmolality was lower in Trial W than in Trial S. A significant difference in osmolality was obtained between Trial NF and Trials W and S (P < 0.01). Plasma aldosterone increased significantly (P < 0.01) during exercise and decreased after exercise. No significant differences existed between Trials W and S although aldosterone levels were lower in Trial S than in Trial W. However, a significant difference was found between Trial NF and Trials W or S. The results of this study suggest that plasma aldosterone has an inverse relationship with plasma volume changes and total sodium concentrations. An increase in plasma potassium and a decrease in plasma sodium during prolonged exercise in a warm environment significantly enhanced plasma aldosterone concentration. The intake of water significantly decreased plasma aldosterone during prolonged exercise in a warm environment, but the intake of sodium had no significant effect in this study. / School of Physical Education
186

A comparative study of exercise blood pressure using the Bruce treadmill test and the 3-3-3 exercise test

Naftzger, Lisa A. January 1992 (has links)
The purpose of this study was to compare the exercise blood pressure response of subjects with a history of exercise induced hypertension between the submaximal 3-3-3 exercise test and a maximal Bruce treadmill protocol. Seven male and four female subjects with a mean age of 49 ± 2 years were recruited for the study. All subjects were selected based on a previous elevation of exercise diastolic blood pressure >_ 10 mmHg during maximal exercise.The 3-3-3 test is a short, standardized treadmill test protocol that consists of one stage of treadmill walking at a 3% grade, at 3 miles per hour, for 3 minutes. Subjects completed the 3-3-3 test on one day and the Bruce protocol on a different day with 24-48 hours between tests. Test administration order was randomized and all tests were done at the same time of the morning with all blood pressures taken by the same technician with a mercury manometer.The increase in diastolic pressure from rest was significantly lower (p<0.004) during the 3-3-3 protocol compared to the peak of the Bruce protocol. There were no statistical differences between the change in diastolic pressure from rest to peak exercise when the 3-33 protocol was compared to the Bruce Stage I or when the Bruce Stage I was compared to the peak Bruce diastolic measurement. The mean change in diastolic pressure from rest to peak exercise in the3-3-3 protocol was 3.4 ± 2.6 mmHg as compared to 9.9 ± 2.0 mmHg for the Bruce Stage I, and 15.4 ± 2.4 mmHg from rest to peak exercise with the peak Bruce. There were no differences in resting or standing systolic or diastolic blood pressure values between protocols done on separate trial days. The change in systolic response from rest to peak exercise and the peak systolic pressures were significantly different (p<0.001) between the Bruce Stage I and peak Bruce and between the 3-3-3 and peak Bruce. There were no significant differences in the heart rate and rate pressure product between the third minute of the 3-3-3 protocol and the third minute of the Bruce Stage I (p<0.001).The 3-3-3 test was not able to elicit the same rise in diastolic blood pressure as the Bruce treadmill test in this population, although the Bruce Stage I was able to elicit a response that was not statistically different than the response of the peak Bruce protocol. This implies that submaximal treadmill testing may be a feasible method to screen for the presence of an exaggerated diastolic blood pressure response to exercise. / School of Physical Education
187

Reliability of VOb2s max estimates from the American College of Sports Medicine submaximal cycle ergometer test

Greiwe, Jeffrey S. January 1993 (has links)
The purpose of this investigation was to determine the reliability and validity of VO2max estimates from the ACSM submaximal cycle ergometer test compared to a maximal cycle ergometer test. Thirty healthy male and female subjects aged 21-54 volunteered for this study. Each subject performed a maximal cycle ergometer test and two ACSM submaximal cycle ergometer tests. At least 48 hours elapsed between the maximal test and the first submaximal test while at least 24 hours elapsed between the two submaximal tests. Heart rates were recorded from a radio telemetry monitor and from 15 second palpation of the radial artery. A trained technician performed all palpations and was blinded from the telemetry monitor during testing to eliminate any bias. Maximal oxygen uptake (VO2max) was estimated by extrapolatingrate for each submaximal trial. To determine inter-test radio telemetry monitor (MON), to an age predicted maximal heart reliability between submaximal trials, correlational analysis andt-test were performed. A correlation of r= .863 and r= .767 were found between the two trials for MON V02max and PALP VO2max respectively. Paired t-test revealed no significant difference (p< .01) between MON V02max 1 and MON VO2max 2 or between PALP V02max 1 and PALP VO2max 2. Although there were no significant differences between trials, the mean data was often not indicative of the individual data since there were 8 MON VO2max cases and 19 PALP VO2max cases where VO2max estimates varied by > 0.5 L/min. There were significant differences between all V02max estimates when compared to measured VO2max and mean percent error in estimates for MON VO2max and PALP VO2max were 25.7% and 33.8%, respectively. The mean error of MON VO2max 1 and MON VO2max 2 were .61 and .63 L/min, respectively. The mean error for PALP VO2max 1 and PALP VO2max 2 were somewhat higher at .90 and .73 L/min, respectively. The present data indicates that a large error is present in VO2max estimates between trials and between measured and estimated VO2max. Therefore, caution must be used when interpreting VO2max estimates from the ACSM submaximal cycle ergometer test. / School of Physical Education
188

The influence of submaximal blood lactate measures on VOb2smax estimates using a submaximal branching protocol

Fischer, Karin Christine January 1996 (has links)
The purpose of this study was to examine if measurements of submaximal blood lactate may improve the prediction of VO2max from submaximal exercise tests. Subjects (39 men & 21 women, age 20-44 yrs) completed a branching protocol on a cycle ergometer which consisted of 3 submaximal stages of 4 minutes each followed by a maximal effort. During the last minute of each stage heart rate (HR) was recorded from telemetry and a capillary blood sample was obtained from a finger puncture. Maximal power output was estimated from the extrapolation of the 3 submaximal HRs to age predicted HRmax and blood lactate concentration was measured using a Yellow Springs analyzer (Yellow Springs, OH). Data were analyzed using multiple regression procedures. Estimated maximal power output (238 ± 56 W) was significantly related to measured VOzmaX (p < 0.001, r2= .523). Mean values for ACSM estimated, ACSM-revised and measured VOz.X were not significantly different (3.170 vs. 3.140 vs. 3.260 L/min respectively), however the SEE % for the ACSM and ACSM revised estimated VOz,. were 13.4% and 12.1%, respectively. When the change in power output relative to the change in blood lactate concentrations (po/BL) from stage 1 to stage 2 and the estimated maximal power output from 3 submaximal heart rates were added as independent variables to the regression model with measured VO2,t as the dependent variable, po/BL was significantly correlated with VO X , accounting for 7.6% of the variance in VOz... In conclusion, only the relative change in power output to the relative change in blood lactate measure from stage 1 to _2 were significant in improving the estimation of VO2 during submaximal exercise tests using a branching protocol. Other blood lactate measures did not improve the estimation of VOA,. in this study. / School of Physical Education
189

A comparison of the health and fitness benefits received with varying quantities of energy expenditure

Swartz, Ann M. January 1998 (has links)
The Surgeon General's Report on Physical Activity and Health recommends expending 200 kcals "on most, if not all days of the week" (1000 to 1400 kcals/week) as a minimum quantity of exercise energy expenditure (EE) required to obtain health benefits. The ACSM recommends expending a minimum of 1000 kcals/week to receive fitness benefits. The purpose of this study was to evaluate the effect of EE above and below 1200 kcals/week on health and fitness benefits. Twenty-six previously sedentary males and females (mean age = 47 ± 2 years), with at least one risk factor for CAD completed the 22-32 week endurance exercise training study. Subjects performed an initial health screening and treadmill test which included measures of heart rate, blood pressure, blood lipids, body composition at rest, and metabolic data (V02, VE, RER) during the maximal treadmill test. Subjects began exercising with the Adult Physical Fitness Program at a self-selected amount of energy expenditure, recording heart rate, frequency, and duration of exercise on an exercise log card after every exercise session. After 22-32 weeks, subjects returned to the laboratory for a final evaluation identical to the first. The metabolic data from the initial and final tests, along with the data from the exercise log card was used to develop an estimation of energy expenditure/week. Subjects were then categorized into either < or > 1200 kcal/week energy expenditure. Results of the pre/post (n=12) training blood pressure, blood lipids, body composition and V02 __ measures were:EE <1200 kcalsEE >1200 kcalsVariablePre TrainingPost TrainingPre Training 'PostTrainingVO2.(L/min)2.287+.1982.397±.1983.064±.2073.290±.210VO2.(ml/kg/min)27.4+1.7-28.2+1.7-33.0+2.4-37.3±2.6 #HDL-C(mg/dl)51+4.355±4.547±2.850±3.2SBP(mmHg)121±4117±3124±4y120±37BMI(k g/m2)28.0±1.728.3+1.731.2+1.6730.0+1.5y #*p <0.05 training main effect, #p < 0.05 group by time interaction, y: n=14The group that expended above 1200 kcals/week displayed more improvement inrelative V02 n,.,., and BMI following the training program than the group thatexpended less than 1200 kcals/week. Furthermore, there was a training main effect showing adaptations in V02 ., HDL and SBP. In conclusion, previously at risk, sedentary individuals exercise training > 2 days/week can receive health and fitness benefits. However, those expending more than 1200 kcals/week will receive a greater benefit in terms of body composition and cardiovascular fitness. / School of Physical Education
190

The development of a normative reference standard for maximal oxygen con[s]umption using the Ball State University-Adult Physical Fitness Program cohort / Development of a normative reference standard for maximal oxygen conumption using the Ball State University-Adult Physical Fitness Program cohort / Development of a normative reference standard for maximal oxygen consumption using the Ball State University-Adult Physical Fitness Program cohort

Hong, Ki-Ho January 2005 (has links)
Background: Normative values of VO2max have been developed or updated based on the estimated VO2max, but measured normative values of VO2max have not been developed yet. VO2max has been reported to relate to coronary heart disease (CHD) risk factors, yet most of the studies have used estimated VO2max to compare CHD risk factors. Therefore, the purpose of this study was to develop norms for VO2max from the Ball State University (BSU) Adult Physical Fitness Program cohort that represented percentiles based on the measured VO2max. In addition, this study evaluated the relationship between measured VO2max and six coronary heart disease (CHD) risk factors, which include Body Bass Index (BMI), high density lipoprotein cholesterol (HDL-C), glucose, triglyceride (TG), total cholesterol (TC) and resting blood pressure (BP).Methods: Subjects were healthy men (N=1,867) and women (N=1,253), ranging in age from 19 to 75 years, who completed the standard BSU Adult Physical Fitness Program quiet and exercise testing sessions between 1971 and 2000, with the graded exercise testing (GXT) conducted with one of the following protocols including modified walking, running, Balke, Bruce, and BSU/Bruce ramp. To be included, subjects had to achieve respiratory exchange ratio (RER) >1.0 during their exercise test.Results: All subjects were classified into ten group determined by deciles of VO2max for each decade of age for males and females respectively. A linear regression showed that VO2max decreased 10.1% per decade (0.44 mi.kg'•min'•yr') for men and 9.7% per decade (0.32 ml•kg-l.min-l.yr') for women. There was no significant difference in the rate of agerelated decline in VO2max per decade between men and women or between deciles of VO2max. Also, the percent of subjects with an exercise history code >5 (regularly participate in exercise at least 3 days per week) was higher in the higher VO2max deciles. In addition, five positive CHD risk factors were inversely related to VO2max, and one negative CHD risk factor was directly related to VO2max. As expected, the higher CRF groups had a more favorable CHD risk factor profile. Also, the mean of VO2max decreased with the greater number of CHD risk factors.Conclusion: This study developed normative values of the VO2max based on measured VO2max. VO2max was significantly correlated to CHD risk factors. / School of Physical Education, Sport, and Exercise Science

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