published_or_final_version / Physiology / Doctoral / Doctor of Philosophy

published_or_final_version / Biological Sciences / Master / Master of Philosophy

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While a great deal of research has been directed towards investigating the age-related decline in V02max, the effect of physical activity on the age-related decline in V02max has not been clearly established. Therefore, the purpose of this study was to examine the relationship between physical activity and the age-related decline in maximal oxygen consumption (VO2max) in apparently healthy individuals. In order to assess the effects of physical activity on the age-related decline in V02max, physiological data was obtained from 142 former participants (116 men and 26 women) (40 ± 8.0 years), in the Ball State University Adult Physical Fitness Program across an average of 12 ± 4.5 years. The subjects were divided into three physical activity group categories depending on their self-reported physical activity status at the time of the first and follow-up test. Those subjects who were sedentary at the first and last test were designated as SED-SED. Those who reported sedentary at the first test and active at the last test were designated as SEDACT and those who were physically active at the time of both tests were designated as ACT-ACT. The data from the analysis revealed that the rate of decline in V02mx expressed as change per year among adult men varied as a function of their reportedphysical activity habits. Those men designated as SED-SED and ACT-ACT experienced a statistically significant decline (p<0.05) in V02max during the follow-up period, while, those men designated as SED-ACT maintained their V°2max. The rates of the change in V02max (ml-kg- 1•min-1) for the men were -0.45, 0.03 and -0.22 ml•kg-l-min-1•yr1 for the SED-SED, SED-ACT and ACT-ACT groups respectively. The percent decline in V02max were 6%, 11% and 2% respectively. A statistical comparison of the rate of change among physical activity groups indicated a difference between the SED-SED and SED-ACT groups (p<0.05). Within the limitations of this study, these data suggested that there was no statistically significant difference in the rate of change in V02max (ml•kg-1•min-1-yr1) between the SED-SED and ACT-ACT physical activity groups. However, when presented as percent change per decade, the decline for those men who were sedentary at both time points was twice that of those men who reported an active lifestyle at both time points. Although the rates of change were not different for the SED-SED and ACT-ACT physical activity groups, those men with a physically active lifestyle maintained their aerobic power advantage as compared to sedentary men who remained sedentary. Furthermore, sedentary men who took up an active lifestyle had offset the decline in V02max (ml•kg-1•min-1) attributed to physical inactivity.The rates for the change in V02max (ml•kg-1•min-1-yr1) for the women were -0.36, 0.20 and -0.21 (ml•kg-1•min-1-yr1) for the SED-SED, SED-ACT and ACT-ACT groups respectively. While these changes were similar in direction and magnitude to those observed for the men, there were no statistically significant differences among the female groups (p>0.05). Therefore the results from the present study were inconclusive for women possibly due to the low sample size (n=26). / School of Physical Education

The purpose of this study was to evaluate whether the current CDC/ACSM physical activity recommendation, ("30 minutes or more of accumulated moderate-intensity activity, most if not all, days of the week") would improve women's health through a reduction ofcoronary heart disease (CHD) risk factors. Twenty-one sedentary females (ages 49 ± 7 yrs.) with one or more CHD risk factors underwent baseline laboratory including: resting heart rate and blood pressure, resting electrocardiogram, body mass index, bioelectrical impedance, skinfold measures, waist-to-hip, blood lipid profile, and V02max. The VO2 was determined by an exercise treadmill test using the Ball State University Ramp protocol. The subjects were instructed on the CDC/ACSM recommendation, the physical activity survey, and given examples of moderate-intensity activity. The survey data was collected bimonthly over the six month period. The subjects reported participating in >_ 30 min. of moderate-intensity activity an average of 4 f 1 days/week with an average duration of 54 ± 26 min. On the remaining days, the subjects reported doing an average of 14 ± 6 minutes per day. Also, 90% of the women reported doing the activity in continuous bouts. Following the six month study period, the women were retested in the laboratory. Sixteen subjects completed the post-testing. The results of the sixteen women showed a significant improvements in HDL-cholesterol (51 ± 15 vs.56 ± 15 mmHg; p=<.05) and TC/HDL ratio (4.5 ± 1 vs.4.25 ± 1.3; p=<.05). There were no significant changes in the other risk factor variables examined or their V02,„.. It was concluded that the majority of previously sedentary, middle aged women can not meet the CDC/ACSM recommendations for daily activity and total energy expenditure. Additionally, it appears that when given the choice, these women choose to do activity in continuous time blocks versus breaking the daily activities into shorter time periods. / School of Physical Education

This study examined the effects of two distinct phases of endurance training (summer and in-season training) in previously well-trained male and female high school cross-country runners. Eleven males and 11 females from the same high school training program were recruited for the three testing sessions: post-track season (June), postsummer training (mid-August), and post-cross-country season (early-November). However, due to injury and other circumstances, only 10 males and 4 females completed all testing sessions. Thus, baseline characteristics were analyzed for both genders; however, longitudinal analysis was only conducted using the males. Submaximal measurements included running economy (RE), blood lactate concentration ([BLa]), and heart rate (HR) at three running speeds in females (6, 7, and 8 mph), and males (7, 8, and 9 mph). Maximal measurements of oxygen uptake (VO2max) and HR, neuromuscular characteristics of isokinetic knee extension strength and vertical jump height, and body composition were also measured. Baseline results showed that the males possessed a higher VO2max, greater neuromuscular characteristics, and lower submaximal [BLa] and HR values than the females. Longitudinal analysis of the males showed that there was an increased VO2max, decreased maximal HR, and decreased neuromuscular strength following summer training. In-season training precipitated further increases in VO2max, an increase in maximal and submaximal HR, and increased neuromuscular characteristics. RE and [BLa] did not significantly change (p<_ 0.05) throughout the course of the study. Likely, it is the subtle changes in these variables in previously welltrained runners which account for the slower performance times at the beginning of the cross-country season and the improvements thereafter. / School of Physical Education

Cardiorespiratory responses to incremental dynamic exercise were assessed across four different levels of lower-body positive pressure (LBPP) and, as a separate study, during constant load (i.e constant work rate) exercise below and above each subject's ventilatory threshold (VT), both with and without 45 torr of LBPP.

While a limited body of research pertaining to vocal sound quality exists, technological advances in sound analyses have facilitated a reexamination of vocal timbre. The sound quality of sung vowels ([ a], [e ], C i ]) produced by ten baritone/bass singers at the University of North Texas was analyzed by the use of Fourier analysis and electronic digital equipment. This procedure and equipment produced results over a wider frequency range with greater accuracy than prior studies on vocal timbre. The study sought to answer the following questions: (1) Using formant regions between 0-20 kHz for comparison, what similarities and differences can be observed among spectra produced from [a], [e], and [ i ] vowels sung by baritone/bass singers? (2) Using formant regions between 0-20 kHz for comparison, what similarities and differences can be observed among spectra produced from [a], [ e ], and [ i ] vowels sung by baritone/bass singers with regard to individual singers? (3) Approximately what vocal-tract tube lengths were used by baritone/bass singers when performing [a], [e ], and [ i ] vowels? (4) What similarities in vocal-tract tube lengths can be generalized as to [ a], L e ], and [ i ] vowels sung by individual baritone/bass singers? The results of the study suggested that: (1) Below approximately 4 kHz formant frequency location can be generalized by a specific vowel between subjects. (2) Above 4 kHz the generalization of formant frequency location is difficult between subjects singing the same vowels, but general frequency location for formants can be identified between samples produced by the same singer performing different vowels. (3) Subjects did alter their vocal-tract lengths as different vowel sounds were performed, but no overall pattern of tube length with reference to specific vowels was indicated. (4) Each singer did use a unique vocal-tract length. The average estimated vocal-tract length for all subjects singing a specific vowel revealed little variation in tube length with an average tube length of 278.97 mm.

The purpose of the investigation was to compare mean voice onset time in young and old male subjects, as well as to examine variability of VOT productions with age for prevocalic bilabial, alveolar, and velar voiced and voiceless stop consonants. Forty-five Caucasion.males were divided equally into three.age groups. Ten tokens of six stimulus words were recorded and wide band spectrograms were made. Results of an analysis of variance revealed no significant differences in VOT with age when averages of the phonemes were used for analysis; however, a significant interaction between age and voiced phonemes was found when individual trials of phoneme productions were used for analysis.