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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.
161

Carbohydrate and free fatty acid utilization in skeletal muscle of trained and untrained men

Evans, William J. January 1976 (has links)
In an effort to determine the relative amount of carbohydrates and free fatty acids (FFA) utilized by trained and untrained men at a submaximal workload and the relationship of selected mitochondrial and glycolytic enzyme activities, six trained and six untrained males were exercised for one hour at 50o of their maximal oxygen uptake (V02 max).Muscle samples were taken from the vastus lateralis in three cyclists and from the gastrocmemius in three runners from each group before and after exercise, and later assayed for succinic acid dehydrogenese, malic acid dehydrogenase, lactic acid dehydrogenase, phosphorylane, and carnitine paLmityltransf erase activities, and glycogen levels. Th e post exercise sample was assayed for glycogen, another was sectioned and stained for glycogen and fiber composition (PAS and-glycerolphosphate dehydrogenase) and from a third coupled mitochondria were isolated to determine 14'CO2 production from oxidation of varied levels of 14C-palmityl-CoA. Blood drawn before, immediately after, and thirty minutes after the exercise was assayed for FFA, glycerol, triglycerides, and glucose levels. Activities of oxidative enzymes (SDH, MDH, and CPT) were significantly higher (2-3 times greater) in the trained individuals than in the untrained group. Glycolytic enzyme activities were higher in the untrained group, probably due to higher fast twitch fiber populations. During exercise, FFA levels rose to the same degree in both groups; however, glycerol levels increased almost five times greater during the exercise in the trained subjects indicating the FFA turnover was much larger in the trained subjects. Blood glucose levels increased by an average of 11 mg% during the exercise in the trained subjects but fell by 8 mg% in the others, suggesting a greater selective uptake by the untrained subjects. Muscle glycogen depletion was 66% greater in the untrained group. These catabolic processes were independent of muscle fiber type, indicating that aerobic training increases those enzyme activities associated with FFA oxidation. Trained individuals are thus able to shift to fatty acids as the primary carbon source for the citric acid cycle, sparing glycogen during submaximal work.
162

The effect of caffeine ingestion on cycling performance

Dalsky, Gail Patricia January 1977 (has links)
The intent of this thesis was to study the effects of caffeine ingestion on substrate utilization and muscle metabolism during exercise, as reflected by endurance time to exhaustion. For this purpose, seven trained cyclists performed work bouts at 80% of maximal oxygen consumption to exhaustion after ingestion of caffeine (CAF trial) end under control (CON trial) conditions.Although the work time to exhaustion was not significantly different between the CAF trial, 91.8 (S.E. ± 7.7) min and the CON trial, 85.2 (S.E. ± 10.5) min, five of he subjected did show an average 18% increase in performance following ingestion of 330 mg caffeine. Since there was no elevation of FFA prior to exercise, it was expected that no muscle glycogen sparing would occur during the first 30', 41.7 (S.E. ± 6.1) mM/kg in the CAF trial and 42.1 (S .E. + 6.6) mM/kg in the CON trial. Serum glycerol concentration was significantly (P< .05) during the CAF trial at 10' and 30'. R values were significantly lower during the CAF trial, .87 (S.E. ± .01) than the CON trial, .91 (S.E. ± .01) at exhaustion. Significantly lower (p<.05) perceived exertion ratings were also observed during the CAF trial. These data suggest a positive effect on endurance exercise performance following caffeine ingestion.
163

The effects of policosanol on reaction time, force production, and the blood lipid profile

Fleenor, Bradley S. January 2002 (has links)
Thirty recreationally active individuals, 16 males and 14 females, participated in the study to examine the effects of policosanol supplementation on reaction time, force production and the blood lipid profile. The subjects were matched based on height, weight. gender, current physical activity level and body fat percentage. The matched subjects where randomly assigned to either the policosanol or placebo group. Supplementation period lasted 8 weeks with reaction and decision time measurements taken at baseline, weeks 2, 4, 6 and 8. Force production was evaluated with the Cybex Dynamometer at speeds of 60, 120, 180 and 240 degrees/second at baseline, weeks 2, 4, 6 and 8. Blood was drawn and analyzed at baseline, weeks 4 and 8. A two way repeated analysis of variance was used to analyze differences between pre and post measurement at a significance level of p <_ .05. There were no significant changes in reaction ordecision time between groups. Force production significantly increased in both groups however, there was no significance between groups. The blood analysis demonstrated significant changes in total cholesterol and triglycerides. No differences were found in high-density lipoprotein cholesterol, low-density lipoprotein cholesterol or liver function measurements. It was concluded that further research in needed to examine the effects of reaction time in older individuals with possibly slower reaction times. The increase in force was due to a training effect and not from policosanol supplementation. However, future research with policosanol and strength needs to incorporate a training protocol. The trend observed with the blood parameters was concluded be a normalizing effect rather than a lowering effect. / School of Physical Education
164

The relationship of growth factor and muscle soreness to muscle hypertrophy

Kim, Jeong-Su January 1998 (has links)
The purpose of the present study was to examine the relationship between exercise induced muscle damage and growth factors during two different modes of exercise. Nine healthy untrained male subjects participated in this study and performed two separate single bouts of isokinetic concentric (Con) and eccentric (Ecc) leg extension exercise on the CYBEX NORMT°". The workload was maintained at 75% of 1 RM for each trial, respectively. The maximum sets of 10 repetitions were performed during the Con trial, and the number was also duplicated during the Ecc trial, with 40 seconds of rest between sets. Serum levels of hGH, creatine kinase (CK), and lactic acid were measured, and the CK level was used to determine the degree of muscle tissue damage. A muscle soreness questionnaire was provided to the subjects to assess the degree of quadriceps muscle soreness following each trial. The EMG activity of the rectus femoris and vastus medialis muscles was recorded during each trial. The results of the present study demonstrated no significant differences in hGH output and CK activity between the exercise trials, although there was a significant different lactic acid response (P < 0.05). However, the Con trial produced significant increases (P < 0.05) in hGH and CK levels above the resting value at the post-exercise times. In fact, the 75% Con trial conducted in this study induced an increase in hGH release (peak: 8.23 ± 3.21 ng/ml) that was 2 X higher than a 120% Ecc trial (peak: 3.8 ± 1.2 ng/mI) of the prior study. The results of the present study demonstrate that a single bout of Con resistance exercise at the same intensity (75% of 1 RM), angular velocity, and ROM as a single bout of Ecc exercise can produce greater increases in hGH output and CK response than its Ecc counterpart. This finding does not support the previous results from this laboratory, showing that Ecc exercise is a stronger promoter of hGH output. However, it suggests that the amount of work performed is an important factor for hGH release because the exercise volume applied in the present study was greater than that of the prior study. The CK response of the subjects in this study, as well as the previous work indicate that hGH output is also dependent on exercise that elicits muscle damage. Therefore, the results of the present study suggest that the mode of exercise, Con vs. Ecc, is not as important as the stress placed on the exercising muscle in order to induce optimal muscle hypertrophy. / School of Physical Education
165

Effects of concentric vs eccentric resistance training on skeletal muscle adaptations in humans

Raue, Ulrika January 2001 (has links)
The Beothuk Indians were an extinct group of Amerinds who were among the earliest founders of Newfoundland. In literature, the Beothuk were described as perhaps being phenotypically more similar to Europeans than Asians (Gatschet 1890, Lloyd 1875, 1876a, Marshall 1996). In this research, mitochondrial DNA (mtDNA) analysis was performed on a Beothuk individual in order to determine his haplotype and, perhaps, shed light on the origins of the Beothuk.For this analysis, a tooth of Nonosabasut, a Beothuk chief who died in 1819 was loaned from the Royal Museum of Scotland. Ancient DNA was extracted from 172 mg of dentin from the tooth. The DNA was cut with two blunt-end restriction enzymes, RsaI and HaeIII. Double-stranded DNA adapters were ligated to the blunt ends. A single adapter was used to amplify the resulting fragments using PCR. In this manner, two libraries of the DNA were created that could be readily reamplified using a small amount of the PCR product. mtDNA type was determined by amplifying specific regions and performing Restriction Fragment Length Polymorphism analysis and sequencing. It was determined that the Beothuk individual had a 9-bp deletion at nucleotide position (np) 8272, an Alul restriction site at np 5176, and heteroplasmy for a HincII restriction site at np 13,259, indicating that the Beothuk individual falls into the Native American Haplogroup B. Haplogroup B is not present in modern Siberian populations, whereas the remaining Native American mtDNA haplogroups are. It has been hypothesized that Haplogroup B arrived in the Americas at a different time than haplogroups A, C, D, and X, about 16,000-13,000 YBP (Years Before Present) (Starikovskaya et al. 1998). Haplogroup B can be found in some modern Taiwanese, Japanese, Korean, Evenk, and other Asian populations.Sequencing of the D-Loop region revealed a G to A transition at np 16303. To our knowledge, this transition was never previously reported in a Native American. This transition has been reported in Tibetans, Koreans, Hans, and Japanese, all considered to be southeast Asian Causacoids (Torroni et al. 1993b, 1994b). This transition, also frequently described in the Caucasian Haplogroup H, is especially prevalent in Spain and among the Basque. It is described as a root haplotype of Haplogroup H whose expansion was estimated to be between 12,300-13,200 YBP (Torroni et al. 1998). This time estimate coincides with the expansion of Haplogroup B. One possible explanation for this transition may be some admixture of the Beothuk with a Caucasian population. / School of Physical Education
166

Effects of volume of resistance training on muscular strength and endurance

Kaleth, Anthony Scott January 1998 (has links)
The American College of Sports Medicine recommends a resistance exercise routine that consists of a minimum of 1 set of 8-12 repetitions on 8-10 exercises, 2 times per week. These guidelines are less than traditional programs and are based on the premises that longer programs are associated with lower adherence and that additional sets and repetitions produce little, if any, additional increases in strength. Therefore, the purpose of this study was to determine if greater gains in strength and endurance could be attained by doubling the recommended dose. Sixteen subjects were randomly assigned to one of two training groups that performed 1 or 2 sets of 8-12 repetitions for 10 weeks on 7 exercises (chest press, lat pull-down, leg ext., leg curl, shoulder press, triceps ext., biceps curl) and 8 subjects were assigned to a non-training group. Pre- and post-training 1repetition maximum (RM) and muscular endurance were measured. To assess endurance, subjects completed as many repetitions as possible at 75% of their pre-training 1-RM on all exercises except the shoulder press (60% of 1-RM). Both training groups showed a significant increase in 1-RM strength and endurance compared to controls (P < 0.05). Only the biceps curl exercise showed a significant difference in strength between the two training groups (P < 0.05). The 2 sets group increased post-training endurance to a greater degree than the 1 set group, but only the lat pull-down exercise was significant (P < 0.05).. Contrary to previous studies, these findings pertain to 8-10 exercises that use larger muscle groups. It was concluded that 1 set of 8-12 repetitions was as effective as 2 sets in increasing muscular strength and endurance. / School of Physical Education
167

Histochemical and biochemical changes in human muscle following 17 days of unilateral lower limb suspension

Short, Kevin R. January 1997 (has links)
The present study was undertaken to determine the relationship between perinatal complications and subsequent development of Attention Deficit Hyperactivity Disorder (ADHD) and other behavioral characteristics. The biological mothers of 74 children diagnosed with ADHD and 77 children displaying no characteristics of the disorder completed the Maternal Perinatal Scale (MPS), the Behavior Assessment System for Children-Parent Rating Scales (BASC-PRS), and a demographic survey. In addition, the biological mothers of 120 children with no characteristics of ADHD or any other behavior disorders completed only the MPS so that exploratory factor analysis of the MPS could be completed.Following factor analysis, stepwise discriminant analysis of the resulting five factors was utilized to explore the nature of the relationship between such perinatal factors and ADHD. Results of this analysis indicated that emotional factors, or the amount of stress encountered during pregnancy and the degree to Relationship Between Perinatal Complications 3 was planned, were the items that maximized the separation between the ADHD and Non-ADHD groups. Additional discrimination between the groups was attributed to the extent of insult or trauma to the developing fetus and the outcome of prior pregnancies. ADHD children were also found to have experienced twice as many behavioral, social, or medical problems, and were more likely to reach developmental milestones with delays.Stepwise discriminant analysis also revealed the Attention Problems and Hyperactivity scales of the BASC-PRS were most significant in differentiating between the ADHD and Non-ADHD subjects. Using the BASC-PRS resulted in approximately 90% of the total sample being correctly classified as ADHD or Non-ADHD. Canonical correlation analysis indicated that emotional factors and the general health of both the mother and the developing fetus were the best predictors of later behavioral patterns reported on the BASC-PRS. / Human Performance Laboratory
168

Resolution of muscle wasting during an acute exacerbation of chronic obstructive pulmonary disease (COPD)

Reavell, Colleen Frances. January 1999 (has links)
Weight loss and depletion of fat-free mass commonly occurs in patients with COPD. The objective of the study was to determine the magnitude and duration of protein depletion during an episode of acute exacerbation. Fifteen patients (9 women and 6 men) admitted for an acute exacerbation of COPD participated in a descriptive study that prospectively measured individual nitrogen balance over a 6-week follow-up period using repeated nitrogen balance tests. / The mean nitrogen balance in hospital was -13.20 +/- 11.63 g N/day. Only 2 patients achieved a positive nitrogen balance by 2 weeks post-admission and 4 more patients by 4 weeks post-admission. At 6-weeks post-admission, 7 patients (47%) were still in negative nitrogen balance (-10.75 +/- 9.34 g N/day). Protein and energy intakes were significantly higher in patients who achieved a positive nitrogen balance (1.7 +/- 0.5 g protein/kg/day and 120 +/- 30% of estimated energy expenditure (1.7 x REE)) than patients who remained in a negative nitrogen balance (1.3 +/- 0.6 g protein/kg/day and 70 +/- 20% of estimated energy expenditure). There were no significant changes in weight or handgrip strength over the follow-up period. No effect of cumulative or daily corticosteroid doses on nitrogen balance or changes in handgrip strength were found. / In conclusion, the catabolic stress of an acute exacerbation on nutritional status is remarkable. Patients admitted for an acute exacerbation of COPD are in severe negative nitrogen balance, which improves very slowly post-discharge. A negative nitrogen balance is prolonged in patients who have a decreased protein and energy intake.
169

Strength, power, flexibility, and bone density in adult men

Adams, Kent 14 July 1992 (has links)
Graduation date: 1993
170

A comparison of two different positions for isokinetic testing of hamstring performance following ACL reconstruction using the hamstring tendon graft /

Uy, Jeric. Unknown Date (has links)
Thesis (MAppSc in Physiotherapy)--University of South Australia, 1996

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