This study investigated whether or not a relationship exists between ventilation and oxygen uptake at 40% and 85% of V02 peak intensity in 30 upper body fit and 30 unfit 18- 35-year-old women. The correlations between ventilation and oxygen uptake at 40% of peak intensity for the fit group (r = -.51) and the unfit group (r = -.48) were modestly negative. At 85% intensity the relationship between ventilation and oxygen uptake in the two groups was -.44 and -.66, respectively. The lower correlations between ventilation and oxygen uptake observed at the 85% level of peak intensity among the unfit group could be due to a lower ventilatory threshold (66% = fit; 49% = unfit), lesser local muscle changes, along with reduced lactate and C02 management; all of which would be improved with training.

The concept of maximal oxygen consumption (VO2 max) implies that there is a limit to the amount of oxygen that can be consumed by an organism in a given time. Many attempts have been made to delineate exactly what factor or factors are limiting to VO2 max. Current models focus on the steps over which oxygen must traverse in order to get from the ambient air to the mitochondria. However, no model has addressed the issue of whether or not carbon dioxide flux may impose a limit to VO2 max. Impedance of carbon dioxide flux may have a deleterious effect on intracellular pH, which in turn, may effect mitochondrial oxidative performance.

The purpose of this study was to determine the validity of the Ebbeling one-stage submaximal treadmill protocol to estimate maximal oxygen uptake in overweight males and females. Forty-five male and females (36.5±10.9 years; 170.2±9.9 cm; 77.9±9.0 kg) were categorized into overweight groups using a BMI of 25-29.9 kg/m2. The subjects performed a submaximal protocol that consisted of one 4-minute stage with individualized speeds of 2.0-4.5 mph at 5% grade and subsequently performed a maximal exercise test. There were significant relationships between observed and estimated VO2max for males (r=.796), females (r=.426), and gender combined (r=.844). There was an underestimation in the estimation of VO2max in the present study when comparing males (10%), females (26%) and gender combined (17%) subjects. The results indicated that a body mass index between the values of 25-29.9 kg/m2 did create a difference in estimating VO2max in the present study when comparing that to Ebbeling et al. (1991).Ball State UniversityMuncie, IN 47306 / School of Physical Education

No description available.

A great deal of research has been done to assess the effects of exercise intensity and duration on excess post-exercise oxygen consumption (EPOC). But the effects of an elevated core temperature (Tc) post-exercise have not been directly examined. To assess the effects of an elevated Tc on EPOC, eight healthy, active male subjects (27.5 ± 6.1 years) underwent two 45 minute exercise trials at =70% VO2max in an environmental chamber (36 °C / 10% RH) followed by a 45 minute recovery in either the environmental chamber (42 °C / 10% RH) wearing insulating clothing (HC), or in the ambient conditions of the testing lab (22 °C / 42% RH) without any additional clothing (AM). Oxygen consumption (V02), minute ventilation (VE), heart rate (HR), and rectal temperature (Tc) were recorded pre-, exercise, and post- during both trials. Subjects were monitored postexercise for 45 minutes. EPOC was determined by subtracting pre-trial V02 from the recovery V02 until the difference between the values equaled zero or until 45 minutes had elapsed. Within 25 minutes post-exercise, V02 during the AM recovery had returned to near resting levels (p = 0.146), while V02 during the HC recovery remained significantly elevated for at least 45 minutes (p = 0.027). Given that V02 remained significantly elevated through 45 minutes of recovery, and that all other measured variables (HR, VE, and respiratory exchange ratio) were significantly affected during the HC recovery, it is clear that an elevated Tc has an effect on EPOC. / School of Physical Education

Numerous cross-sectional studies have reported an inverse relationship between VO2,,,ax and age. However, few longitudinal investigations have compared the rate of decline in VO2,,.x between women who did or did not report exercise habits consistent with the 1990 ACSM position stand for quantity and quality of exercise. The purpose of this study was to determine if changes in exercise habits and body composition affected age-related changes in VO2.x. Subjects were 91 women (age 40.9 ± 8.8 years at baseline) tested twice between 1973 and 1996 (range of 3.1 - 21.9 years, mean interval of 9.3 ± 4.2 years). The subjects were divided into four physical activity groups based on their reported exercise habits at baseline and follow-up as: non-exercise - exercise (NE-EX; n = 21), NE-NE (n=36), EX-EX (n=19), and EX-NE (n=15). Baseline VOz,,,ax (ml-kg-1-min-1) was significantly higher for the EX vs. NE ( 38.4 ± 8.4 vs.28.8 ± 5.7; f42.2; P<.0001). ANOVA revealed significant differences between the physical activity change groups and mean percent changes in VO2. (% A ml•kg'.min'-yr') (F =10.887; P<.0001) which are listed in the following:NE-NENE-EXEX-EXEX-NE-1.081.58*-1.25-2.21* NE-EX vs. EX-NE; NE-EX vs. EX-EX; and NE-EX vs. NE-NE (P<0.05)There were differences between the following groups: NE-EX vs. EX-NE; NE-EX vs. EX-EX; and NE-EX vs. NE-NE for percent change in VO2max (nl•kg'-min 1•yr 1) with the EX-NE group having the largest decline in VO2max during the follow-up period.Using a multiple regression model after adjusting for the exercise habit groups, the exercise group scheme accounted for 27.3 percent of the variance in percent change in VO2max at step 1 of the analysis (f = 1.09; P < 0.001). Change in percent body fat and change in maximal ventilation accounted for an additional 7.2 percent and 6.5 percent of the variance at steps 2 and 3, respectively. The change in maximal heart rate accounted for an additional 2.5 percent of the variance at step 4, although the statistical significance of the contribution was low (P = 0.057). Increases in body fat and decreases in pulmonary ventilation were found associated with declines in aerobic power while a decline in maximal heart rate between the tests was associated with a decline in percent change in aerobic power.In conclusion, these data demonstrate that: 1) adoption or maintenance of a regular exercise program is associated with less decline in VO2,,. during long-term follow-up compared to women who did not exercisers, and 2) changes in exercise habits, body composition, maximal ventilation, and maximal heart rate accounted for nearly half (43 %) percent of the percent decline per year. / School of Physical Education

The direct measurement of maximal oxygen consumption (V02 max) has always been the benchmark for the determination of Cardiorespiratory fitness (CRF). However, the time and expense of that type of testing does not lend itself to students in activity classes or adult fitness participants. Therefore, the purpose of this study was to evaluate the validity of a 500 yard shallow water run test in determining CRF. A commonly used field test, the 1.5 mile run, was used as a basis for comparison during the 500 yard water run. Subjects in this study included 15 men and 28 women that completed a 1.5 mile run and a 500 yard shallow water run as well as a graded exercise test to fatigue on a treadmill. Correlations between 1.5 mile runs and the 500 yard shallow water run and VO2 peak were -.89 and -.80 respectively. In addition to simple regression analysis, multiple regression analysis was used to significantly improve the prediction of CRF (p<0.05). Peak HR during the 1.5 mile run significantly improved the 1.5 mile run prediction of CRF (R2=0.78 to 0.82) with a reduction in SEE (3.95 to 3.52 ml/kg/min) from the simple regression alone. Percent body fat and subject height improved the 500 yard shallow water runs prediction of CRF (R2=0.62 to 0.86) with a reduction in SEE (5.14 to 3.19 ml/kg/min). In conclusion the 500 yard shallow water run can be used to accurately predict CRF and with the addition of percent body fat and height provide a better prediction of CRF. / School of Physical Education

Daily variability of walking and naming economy (WE,") was assessed in eight prepubertal (P), eight adolescent (C) and eight adult females (A) on three separate days. Prior to testing all subjects engaged in 15 minutes of treadmill walking and running and performed a graded treadmill exercise test to maximal effort. On 3 additional days WE and RE were measured during five minutes each of walking and running. The order of exercise was randomized and each bout was separated by ten minutes of rest. A one-way analysis of variance (ANOVA) revealed differences (p < 0.05) in height, weight, sum of skinfolds, BSA, VO=Ax (ml-kg' .min 1), HRmAxbetween P vs C, and A. While there were no significant interactions between group and speed, a two-way ANOVA revealed differences between all three groups for WE and RE (p< 0.05). Repeated measures two-way ANOVA revealed significant day-to-day differences in RE but not WE. Coefficients of variation (CV) for economy were significantly greater for walking (4.33) than running (2.33). CV for WE and RE combined were significantly greater in P (4.43) than A (2.42). These results suggest dust daft variability of WE and RE appears to be a function of maturation and growth, with significance being acheived at the extremes of the maturation scale; the prepubescent child and the fully mature adult Furthermore, for research testing purposes, prepubertal children may require greater than two testing sessions, the amount recommended for adults. / Human Performance Laboratory

Bibliography: leaves 162-174. / xiv, 177 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Clinical and Experimental Pharmacology, 1989

Thesis (M.S.)--Worcester Polytechnic Institute. / Keywords: Diabetes; imaging; phosphorescence; retina. Includes bibliographical references (p. 69-70).