Spelling suggestions: "subject:"electeophysiological aspects."" "subject:"exertphysiological aspects.""
1 |
Reduced intraabdominal fat after lower-dose treadmill training in growing female ratsDavid, Lynne Catherine 12 October 2001 (has links)
The presence of an increased accumulation of intraabdominal fat (IAF) has been
linked to dyslipidemia, hyperinsulinemia, and hyperglycemia, which precede the
development of type 2 diabetes and coronary artery disease (CAD). It has been shown
that IAF begins depostition during childhood. Human studies suggest that regular
endurance exercise, that does not necessarily produce an increase in aerobic capacity,
can effectively reduce IAF accumulation during these early years. In contrast to human
research, studies using animal models of human disease typically employ extremely large
volumes of exercise with the intent to maximize aerobic capacity. The present study
examined whether half the amount of endurance training, that was previously reported to
induce cardiac hypertrophy and approximately double the aerobic capacity of skeletal
muscle in rats, would reduce the growth-related accumulation of IAF in growing female
rats. Twenty-two 4-week-old female Sprague-Dawley rats were randomly assigned to a
running experimental or a non-running control group. The runners exercised on a treadmill
5 days/week for 60 min/day at a speed of 27m/min and up a 15% grade for 10 weeks.
After 10 weeks, the parametrial, omental and mesenteric IAF depots and the heart were
excised and weighed. Compared with non-runners, the runners had a significantly lower
mean parametrial fat mass (2.22 g vs. 3.13 g, p=0.05) and a higher mean heart weight
(0.97 g vs. 0.90 g, p=0.05) at the end of 10 weeks. In addition, the lower mean
parametrial fat mass in the runners vs. the non-runners (2.19 g vs. 3.19 g, p=0.02)
remained significant even after adjusting for the greater heart weights of the runners. One-half
the amount of exercise, that was previously reported to induce cardiac hypertrophy
and approximately double the aerobic capacity of skeletal muscle in rats, yielded an 8%
greater heart weight and a 29% lower parametrial IAF mass, on average, in growing female
rats. In addition, the effects of treadmill running on reducing parametrial fat accumulation
were independent of the effects of running on increasing heart weight. Thus, future
studies examining the effects of exercise on IAF and other health-related metabolic
outcomes in rats may consider using lower-dose endurance training protocols that are not
designed to maximize improvements in aerobic capacity. / Graduation date: 2002
|
2 |
Maximal exercise tolerance after induced alkalosisKatz, Abram January 1983 (has links)
Eight healthy males performed two rides to exhaustion at a work load corresponding to 125% Q02 max, one hr after ingesting either NaHCO3 (E) or NaCl (C). Mean + SE pre-exercise blood pH, HCO3 and base excess (BE) values were respectively 7.42 + 0.01, 28.2 + 1.5 mmol/l and 2.02 + 0.1 mmol/l for the E condition, and 7.39 + 0.01, 24.4 + 0.7 mmol/l and -0.4 + 0.7 mmol/l for the C condition (P < 0.05 for all variables). Cycling time to exhaustion (E = 100.66.1; C = 98.6 + 5.7 sec) and total "02 during recovery (E 17.7 + 0.9; C = 17.3 + 0.8 1/30 min) did not differ between treatments. Blood pH, HCO3 and BE were significantly higher while the hydrogen ion to lactate ratio (LH+I/ELAI) was significantly lower in E than in C during recovery. Blood LA levels were also greater in E than in C during the latter part of recovery although peak individual values were not significantly different between trials CE = 14.4 + 0.4; C = 13.3 + 0.0 mmol /1) . In view of the insignificant differences in cycling time, peakLA production was greater in E than in C. Rather it individual LA and total recovery 002, it is not likely that Given this protocol, alkalosis does not help to sustain an appears that LA efflux was enhanced by the NaHCO3 feeding. Additionally, the return of the acid-base status in blood to resting conditions was more rapid during alkalosis does not help to sustain an intense exercise bout. These data suggest, however, that NaHCO3 may be of benefit following repeated work bouts.
|
3 |
The influence of NaHCOb3s ingestion on interval swimming : acid-base balance and performanceGao, Jiaping January 1987 (has links)
The purpose of this study was to investigate the influence of oral NaHCOa administration on the alteration of acid-base balance and performance of high-intensity interval swimming. Ten male college swimmers were studied on five test days within a two-week period. Each test day consisted of five 100-yd freestyle swims with a two-minute rest interval between each bout. Subjects received two NaHCO3, two placebo and one no-drink treatments for the five test days. One hour before the onset of swimming the subjects were given 300 ml of citric acid flavored solution containing either NaCl (placebo) or NaHC03 (experimental), or received no drink. The dose of NaHCO3 solution was 0.25 9/kg-1 body weight. Before the sprint trial test a 300-yd warmup swimming was performed followed by a nine-minute rest. Performance times for each 100-yd swim were recorded. Blood samples were obtained before and one hour after treatment, two minutes after warmup and the last bout of swim. Blood, pH, lactate, standard bicarbonate (SBC) and base excess (BE) were measured. After the statistical analysis had shown there were no differences between the corresponding values of two trials for the same treatment, the data for identical treatments were combined and reanalyzed statistically as one group. All the corresponding variables between placebo and no-drink revealed no differences. Performance times of the fourth and fifth swimming bouts were faster (P < 0.05) and blood lactate after exercise was higher (P < 0.05) in NaHCO3 condition. Blood pH, SBC, BE were higher (P < 0.05) at post-treatment, post-warmup and post-last bout of swim in NaHCO3 condition. The difference between NaHCO3 and the other two conditions on the increment of lactate (2.0 mM) was proportional to that on the decrement of SBC (2.2 meq/1) after exercise. The data from the placebo and NaHCO3 treatments shown a positive correlation between hydrogen ion and lactate concentrations (r = 0.923) and a negative correlation between SBC and lactate concentrations (r = -0.941) after warmup and exercise. These data are in agreement with previous findings that during repeated bouts of exercise pre-exercise administration of NaHCO3 improves performance, possibly by facilitating the efflux of lactate and hydrogen ions from working muscles and thereby delaying the onset of fatigue.
|
4 |
Heart rate and estimated energy cost of women's basketball practiceDwight, Mary Phyl January 2011 (has links)
Digitized by Kansas Correctional Industries
|
5 |
Influence de la déplétion et de la surcharge en glycogène musculaire sur la réponse sympatique au cours de l'exercice prolongéPicard, Denis. January 1979 (has links)
No description available.
|
6 |
Recovery metabolism following exercise above and below the anaerobic thresholdDiotti, Kristin A. January 2003 (has links)
This study determined the effects of exercising above (LATabove) and below(LATbelow) the lactate threshold, upon excess post-exercise oxygen consumption (EPOC) magnitude and duration among average fit females. Thirteen females underwent testing over a nine-day period (5 visits). Resting metabolic rate (RMR) was assessed over two days. A ramp cycle test determined peak V02 and LAT. Blood samples, ventilatory, and heart rate measurements were recorded during rest, exercise, and recovery. On separatedays, volunteers exercised 10% LATabove and LATbelow expending 300 kcals. Afterwards,heart rate, RER, and V02 were measured until within ± 5% of the baseline RMR. EPOC duration was significantly greater for LATabove (61.49 + 8.73 min) than LATbelow (30.72 + 4.81 min). EPOC magnitude was also significantly greater LATabove (24.29 + 3.67 kcals) than LATbelow (13.28 ± 2.10 kcals). This study demonstrated exercising at LATabove adds an additional energy cost component to the recovery dynamics. / School of Physical Education
|
7 |
The effect of progressive resistance strength training exercise on serum growth hormone and testosterone in young and elderly menBrown, Robert G. January 1987 (has links)
The purpose of this study was to observe the response of serum hormones to a progressive resistance strength training program. Basal levels of serum growth hormone and total testosterone were measured before and after a 12-week strength training program in 8 young men (mean age= 23 years) and 13 elderly men (mean age= 63 years). The response of growth hormone and testosterone to an acute bout of strength training exercise was also measured. Changes in lean body mass, percent fat, fat weight, VO2max and girth measurements were determined.Sessions were started with walking and static stretching exercises for the major muscle groups. This was followed by 45-60 minutes of isotonic strength training exercise which consisted of the leg-press, leg-extension, leg-curl, torso extension, bench-press, pull-down, pull-over, horizontal arm adduction, arm adduction, and modified sit-ups on an abdominal platform. Subjects were told to increase weight at a station when they could successfully complete three sets of ten repetitions at that station. At weeks 2 and 12 of the study subjects were strength tested at the leg-press, leg-extension, and bench-press stations. Strength was measured as the most weight that could be lifted for six repetitions. Blood samples were drawn from an antecubital vein pre and post training, and before, immediately following and 15 minutes after an exercise session.There was a significant increase (p <0.001) in strength for both groups for the leg press, leg extention and bench press. However, the young group was significantly stronger (p <0.001) than the elderly group in both pre and post test for all muscles measured. There was a significant increase (p <0.01) in lean weight in the elderly group which was correlated with increased strength on the leg press, leg extension and bench press on the post test. There was a significant increase (p <0.05) in growth hormone for both groups in response to an acute bout of exercise on both the pre and post test with the rise being significantly higher (p <0.025) in the young group. The increased strength in the young group correlated positively with increased serum growth hormone following an acute bout of exercise on the post test. There was no significant change in serum testosterone in response to an acute bout of exercise in either group. Basal levels of growth hormone and testosterone did not change.
|
8 |
Effects of physical training on the heart rate and electrocardiographic response to sudden exertionElger, David H. January 1979 (has links)
Five policemen (26-46 years) participated in a Police Fitness Program lasting for 13 to 16 weeks. They either jogged or combined walking and jogging for a minimum of two miles per session until the time of the post test. As a result, all of the officers reduced their percentage of body fat, and four of the five policemen increased their maximal oxygen consumption. Training had no effect on the initial heart rate response to a fifteen second sudden exertion run on the treadmill at nine mph., twenty percent incline. The rate of recovery, however, was improved in all subjects. No electrocardiographic abnormalities were observed either before or after training. Because a limited number of subjects completed the study, the amount of data was insufficient to make any conclusive statements about the effects of physical training on the heart rate and electrocardiographic response to sudden exertion.
|
9 |
Determining exogenous glucose oxidation during moderate exerciseBozac, Anna Elena January 1990 (has links)
The purpose of this study was to determine the quantity of a glucose drink oxidized during cycle ergometer exercise at 60% VO₂max for 75 minutes. A second purpose was to determine if the glucose drink improved sprint time to exhaustion at 90% VO₂max after 75 minutes of exercise. Six trained male cyclists (VO₂max > 60 ml•kg⁻¹•min•¹) exercised on three occasions during which they ingested either water ad lib (W), ¹³C-cornsyrup (100 g, 2.02 M) + water ad lib (CS), or NaH¹²CO₃/NaH¹³CO₃ mixture (5 mg•kg⁻¹, 1% ¹³C-enriched) + water ad lib (B). Treatments B and CS were ingested after 5 minutes of cycling at 60% VO₂max. During exercise, there was no difference between treatments in plasma lactate response, changes in plasma volume, sprint time to exhaustion, or in respiratory exchange ratio (RER), VO₂, or VCO₂. RER showed a significant decline (p< .01) from 5 minutes (1.00±0.05, X±SD) to 75 minutes (0.96±0.05), and VO₂ showed a significant positive shift (p< .01) from 3.15(±0.29) to 3.52(±0.45) l•min⁻¹. A transient rise in plasma glucose was observed with CS. Changes from rest in ¹³C/¹²C ratio (∂13C) showed a significant increase (p< .01) following CS. Peak glucose oxidation rate was 7.26 g•15 min⁻¹ which occurred after 75 minutes. Total dose of exogenous ¹³C-glucose recovered as ¹³CO₂ (above baseline) was 22%. These observations suggest that (1) during moderate exercise of 75 minutes duration, oxidation of exogenous glucose occurs within 15 minutes but contributes marginally to total carbohydrate utilization as RER continued to fall with or without CS, and (2) sprint time to exhaustion after 75 minutes of cycling is not improved with glucose ingestion. / Education, Faculty of / Curriculum and Pedagogy (EDCP), Department of / Graduate
|
10 |
Some aspects of exercise physiology in fishKiceniuk, Joe Willie January 1975 (has links)
The limiting factors of swimming performance were studied in fish exercising in a water tunnel. The relationship between (10 min) critical velocity and body length determined in 10 species of freshwater teleosts is discussed with respect to the ratio of lateral red body musculature to total body weight. Electromyographic recording from red and white portions of the body musculature in four species of fish showed that red muscle fibers alone are active during steady swimming at sustained speeds. White muscle fibers are active only during bursts of violent swimming, such as during rapid acceleration and for a brief period preceding fatigue. Thus red muscle fibers, generally accepted as having an aerobic metabolism, appear to be the major determinant of sustained swimming speed.
To establish the time course of cardiovascular and respiratory changes during swimming; heart rate, ventilation rate, dorsal aortic, ventral aortic, and right common cardinal blood pressures were monitored during steady swimming following abrupt changes in water velocity. Under these circumstances most of the heart rate increase occurred in the first thirty seconds and heart rate did not change further after 3-15 minutes at a given swimming speed. Ventilation rate tended to increase initially and then decline, reaching a constant value after 15-30 minutes at a given swimming speed. Dorsal and ventral aortic blood pressure increased more slowly than heart rate, peaking after six minutes then declining to constant values after about 30 minutes. Blood pressure in the common cardinal vein was constant during exercise. The animals were considered to be in a steady state with regards to these circulatory and respiratory variables after about 30 minutes.
Oxygen consumption increased from a mean of 0.58 ml kg⁻¹ min⁻¹ at rest to a mean maximum of 4.34 ml kg⁻¹ min⁻¹. Under the same circumstances cardiac output increased from a mean of 17.6 ml kg⁻¹ min⁻¹ at rest to a mean maximum of 52.6 ml kg⁻¹ min⁻¹. The corresponding stroke volume was 0.46 ml kg⁻¹ stroke⁻¹ at rest and 1.03 ml kg⁻¹ stroke⁻¹. Arterio-venous oxygen difference at rest was 3.29 volumes % and increased to 8.3 volumes % as a result of a decrease in venous saturation (to lower than 10% in some cases) during exercise.
Heart rate at rest was 31.75 min⁻¹ and increased during exercise by a mean of 1.33 times. Ventral aortic blood pressure rose from 38.8 Torr at rest to 61.7 Torr. The corresponding ventral aortic pulse pressure rose from 11.6 Torr at rest to 26 Torr. Dorsal aortic mean pressure at rest was 31 Torr and increased to 37 Torr with exercise, accompanied by an increase in pulse pressure from 5.8 Torr at rest to 10 Torr. Ventilatory volume at rest was 211.4 ml kg⁻¹ min⁻¹ and increased to about 1700 ml kg⁻¹ min⁻¹ at maximal sustained swimming speed. The capacity rate ratio of oxygen exchange between water and blood increased from 0.6 at rest to 1.8 during exercise. Arterial blood of resting trout was 97% saturated with oxygen and % saturation did not change with exercise. Blood lactate at rest and at swimming speeds as high as 93% of critical velocity was 0.5 μM/ml. One minute after fatigue the blood lactate level had increased about five fold and continued to increase, reaching a maximum value (6-10 μM/ml) 2 to 2.5 hours after fatigue. / Science, Faculty of / Zoology, Department of / Graduate
|
Page generated in 0.0714 seconds