The double product break point (DPBP) has been shown to occur in normal and cardiac subjects with values comparable to the ventilatory threshold (VT). The purpose of this study was to evaluate the intramodal and intermodal reliability of DPBP measurements during treadmill (TM) and cycle ergometry (C) exercise and to compare the DPBP to the VT. Seventeen subjects, (eight men and nine women) ages 18-60 (31.5 ± 12.4 yrs), performed four maximal exercise tests, two utilizing a standardized ramp treadmill and two utilizing an individualized ramp cycle protocol. A minimum of 48 hours separated each test. Double product (DP) was measured every 15 seconds during each test via the Kyokko Bussan CM-4001 automated blood pressure unit. Breath by breath analysis of gas exchange measurements were performed. The DPBP and VT was determined visually by three blinded observers (acceptance criteria being at least 2 observers agreeing within 10%). There were no significant intramodal differences in the V02 at the DPBP (ml'kg'1'min 1) for the two treadmill trials (23.8 + 4.9, 23.2 ±5.0) or for the two cycle trials (21.7 +7.2, 21.7 ±6.4). There was also no significant mean intermodal difference in the V02 at the DPBP for the treadmill and cycle (24.4 + 4.4, 23.1 + 5.8). Intramodal intraclass correlations for the DPBP were 0.84 and 0.79 for the treadmill and cycle, respectively. Intermodal intraclass correlation for the DPBP was 0.85. There were significant differences between the DPBP and the VT for both the treadmill (23.3 + 4.7, 28.2 ± 5.3)and the cycle (22.1 + 7.1, 27.5 ± 10.4). Correlations for the DPBP/VT comparison were 0.43 and 0.78 for the treadmill and cycle, respectively. In conclusion, results of this study suggest that DPBP measurements are reliable both intramodally and intermodally, however due to a wide range in correlations, the results suggest that the DPBP and VT are not occurring at similar V02 values. / School of Physical Education

This study was designed to assess the independent effect of a field learning trial, combined with various forms of exercise intensity feedback on the self-regulation of exercise intensity. Following a treadmill test, 42 males (21.8±2.7yrs) were randomly assigned to one of 3 exercise intensity feedback groups: heart rate (HR), heart rate + rating of perceived exertion (HR+RPE) or no systematic feedback (CONT). Half of the subjects in each group, were paced (P) to target heart rate (THR) during the first 800 meter field trial on day 1. Subjects in the non-paced (NP) groups completed the first trial at a self-selected pace. Following the first trial, subjects were instructed to exercise at their target intensity, and received the designated feedback after each of three 800m trials, on four days (D1-D4) within one week. Deviations (±bpm) from THR were recorded following each trial, and group means (S.D.) are presented below. Differences among groups were tested using a 3-way ANOVA (pacing x feedback x trials) with repeated measures across trials.GROUPDAY 1DAY 2DAY 3DAY 4P HR8.8(4.3)2.5(3.6)5.3(4.3)2.5(4.2)NP HR4.8(9.8)3.1(3.8)1.7(1.7)2.3(3.3)P HR+RPE6.1(6.6)1.3(6.4)2.8(5.8)2.1(3.4)NP HR+RPE9.0(9.0)6.9(6.6)4.3(8.0)3.6(5.7)PCONT5.7(5.9)2.9(12.3)5.4(8.8)2.4(13.5)NP CONT *21.67.316.38.416.010.914.17.5* NP CONT > all other groups on each day (p < 0.05)The pacing x feedback x trials interaction was not significant within any day. All groups increased accuracy from D1-D4, with most of the improvement being noted between D1 & D2 (p < 0.01). The addition of RPE (HR+RPE) feedback during the trials did not result in greater accuracy when compared to HR only feedback. Although both the P CONT & NP CONT groups improved across days, the P-CONT subjects were no less accurate than the groups using HR or HR+RPE feedback. Thus, a single 4-5 minute learning trial was as effective as the use of HR and perceptual feedback in the self-regulation of exercise training intensity in the field setting. / School of Physical Education

In adults, serum and salivary cortisol increase during aerobic exercise. There is little data on serum and no data on salivary cortisol responses during aerobic exercise in children. The purpose of this study was to examine serum and salivary cortisol during and after aerobic exercise. Ten male children with a mean age of 10.6 ± 0.6 years were subjects in this study. Each child came to the laboratory on three occasions. The first visit was to familiarize the child with the procedures. On the second visit, each child performed a maximal exercise test on a cycle ergometer (mean VO2. 49.5 ± 3.6 ml•kg''-min-') . On the third visit, an indwelling catheter was placed in a forearm vein. Thirty minutes later baseline blood and saliva samples were obtained followed by 30 minutes of exercise on a cycle ergometer at 69.5 ± 3.0% of VOA. Blood and saliva samples we e obtained at mid-exercise, end exercise and 15 minutes post-exercise. Serum and salivary cortisol were analyzed using RIA skit. Serum samples were corrected for changes in plasma volume. A repeated measures ANOVA revealed that exercise significantly increased serum, but not salivary cortisol. Mean salivary cortisol (ug.dl'') at baseline was 0.079 ± 0.042, at mid-exercise 0.099 ± 0.070, at end-exercise 0.133 ± 0.112, and at 15 minutes post-exercise was 0.143 ± 0.140. Post-hoc analyses indicated that mean serum cortisol at midexercise (7.94 ± 4.53 ug•dl-'), end-exercise (8.72 ± 5.61) and 15 minute post-exercise (8.21 ± 5.03 ug•dl'') were significantly greater than baseline (5.54 ± 2.73 ug•dl-'). The ratio of mean salivary to mean serum cortisol ranged from 1.3% to 1.7%. Serum and salivary cortisol were significantly correlated at mid-exercise (r=0.77), post-exercise (r=0.90) and 15 minutes post-exercise (r=0.84), but not at baseline. It is concluded that: (1) as a result -of exercise, children show adrenocortical activation as measured by serum cortisol; and, (2) salivary and serum cortisol are strongly correlated during and after exercise in children. / School of Physical Education

To investigate the effect of a 12-week internet-based PA intervention (Active Living Every Day (ALED)) on average steps/day and time spent in sedentary, light, and moderate/vigorous activity/day, PA was objectively measured at baseline and follow-up using the Omron pedometer and the Actigraph GT3X in 11 bariatric patients (2 male, 9 female; 41±12 years). Significant changes (p<.05) were found in weight, BMI, body fat %, waist and hip circumference, submaximal RPE, percentage of individuals reporting PA and perceived exercise barriers from baseline to follow-up. No significant differences were found in steps/day or daily activity level from baseline to follow-up. Bariatric participants averaged 4454±203 steps/day and 74% of their day was spent sedentary. Based on this data it appears that the 12 week PA intervention was not effective in significantly changing PA behavior in the pre-surgery, but lead to improvements in cardiovascular risk factors, RPE and potential exercise barriers. / School of Physical Education, Sport, and Exercise Science

There is no abstract available for this thesis.

Knowledge of the magnitude of error in any test measure is important in judging the relative significance of that measure. The purpose of this investigation was to determine the day-to-day variability of, and interrelationships between, three anaerobic ergometer tests. The three tests examined were 30 second sprint bouts on a hydraulically-braked Fitron ergometer, 60 second sprint bouts using this same ergometer, and timed rides to exhaustion at a workload corresponding to 125% VO max. A total of twenty-seven subjects were assigned at random to perform four trials of one of these tests at one week intervals. An additional nine subjects performed one trial of each test. The mean coefficients of variation (CVQ SD x 100%) for the performance measures (mean tolerance power or ride time) were 5.4%. 5.47., and 5.37% for the 30 second, 60 second, and exhaustive tests respectively. The mean CV for 10 minute post blood lactate were 11.0%., 13.9%, and 11.0% for these same tests. The mean CV for peak torque and fatiguability were 6.7 and 10.37 for the 30 second test and 5.67% and 7.5% for the 60 second test. Mean power during the 30 second and 60 second tests were significantly related (r=0.69, p<0.05) l but these measures were not correlated with time to exhaustion. Exhaustive time was, however, significantly related to ten minute post exercise lactate concentration (r=0.91, p<0.01). It was concluded that the biological variability of anaerobic tests is similar in magnitude to that reported for measures of aerobic fitness (VO max). These data also indicate that the exhaustive test is a measure of relative, but not absolute, anaerobic tolerance.

There is no abstract available for this thesis. / School of Physical Education

The physiological responses of hypertensive subjects to a single bout of exercise in a hot environment have been investigated. It was the purpose of this study to compare the effect of successive days of exercise in the heat on borderline hypertensive and normotensive individuals, with particular interest being paid to the positive relationship that exists between plasma volume and blood pressure. Eight hypertensive subjects (HT) and 8 normotensive controls (NT) performed a standardized work task, (walking for 60 minutes at 3.5 mph on a 5% grade), in dry heat, (40C, 257. RH), on 7 successive days. Working capacity and acclimatization were compared during two, 90 minute heat tolerance tests (HTT), one prior to, and the other following the acclimation period.Both groups demonstrated a similar degree of heat acclimation, as reflected in significantly lower HTT2 core temperatures, (P< 0.05), and heart rates, (p< 0.01). Plasma volume expansion over the 9 days was also equal for both groups (+77.), but appeared to have no effect on their resting or exercising blood pressures. No differences were observed in the ability of either group to complete the work task, although the HT group exercised at a significantly higher percentage of their maximal oxygen uptake, (p< 0.05), than the NTs.These results indicate that no abbreviation in working capacity is experienced by borderline HT'% during exercise in the heat as a consequence of their high blood pressure. The anticipated elevation in blood pressure as a result of an expansion i n plasma volume did not occur. Consequently, these individuals show the same positive acclimation to exercise in the heat as their NT counterparts. / School of Physical Education

The purpose of this research was to examine the effects of a premovement silent period (PSP), and an involuntary small amplitude countermovement (CM) on the maximal height of the squat jump (SJ). Fifteen elite male volleyball players (20.6 ± 1.6 yrs) and thirteen untrained males (20.2 ± 1.7 yrs) performed ten maximal effort SJs from identical starting positions. The electromyographic activity of the vastus lateralis and biceps femoris was measured in conjunction with the vertical ground reaction force, and the vertical displacement measured by a cable-extension transducer. The presence of a PSP or small amplitude CM did not increase maximal SJ height significantly (p > 0.05). These findings indicate that in the SJ, facilitation effects of the PSP and small amplitude CM are minimal. This is important to past and future studies utilizing the SJ, as it is often difficult for individuals to perform SJs with no detectable CM. / School of Physical Education

The assessment of ventilatory threshold (Tvent) and maximal oxygen consumption (VO2max) are routine laboratory procedures, yet there are few studies that have directly compared these measurements during different modes of exercise in children. Therefore, the purpose of this study was to compare the physiological and perceptual responses at Tvent and V02max during treadmill and cycle ergometry in prepubertal male children. Ten subjects (M ± SD, 10.2 + 1.3 yrs.) performed a graded exercise test to maximal effort on a treadmill and a cycle ergometer. The order of testing was counterbalanced. The treadmill protocol began at 3.0 mph and 2% grade and progressed in one minute stages. Similarly, the cycle protocol began at 30 watts (W) and progressed 10 W•min-1. For both protocols, each stage was designed to elicit an approximately 3.5 ml-kg-I- min-1 change in V02. In addition, finger stick blood samples were taken at 2, 3, and 5 minutes post exercise in order to assess maximal blood lactate (La) level. Mean V02max on the treadmill (58.2 ± 6.9 ml•kg-l.min-1) was greater (P < 0.05) as compared to the cycle (51.7 ± 7.7ml.kg-'•min-1), with the average difference and the cycle ergometer, V02max is a function of the testing modality. LiKewise, the V02 at Tvent is dependent on the mode of exercise, while Tvent expressed as a percentage of VO2max is independent of mode of exercise. The perceptual responses at Tvent appear to be linked to a percentage of V02max, rather than an absolute V02. / School of Physical Education