Effects of Age, Fitness Level, and Exercise Training upon Autonomic Control of Heart Rate (open access)

Effects of Age, Fitness Level, and Exercise Training upon Autonomic Control of Heart Rate

In this study the effects of age (18-55 years), differing levels of fitness (VO 2max ranging from 35.5 to 68.8ml.kg-1.min-1) and endurance training (10 weeks) on heart rate control were investigated. Fitness level was initially determined by a VO2max stress test, succeeded by cold hand and cold face pressor test of autonomic activity. Following these baseline measurements, the subjects (32 nonsmoking male volunteers) were endurance-trained three to four times a week for a 10-week period. The baseline tests were readministered following the 10-week dynamic exercise training period. These data suggest that a natural consequence of aging is a diminishment of autonomic heart rate control; however, endurance training appears to interrupt the aging influence. Individuals of low fitness level appear to have heart rate control dominated by the sympathetic system, while individuals with high fitness levels have a vagally dominated heart rate control system.
Date: May 1980
Creator: Baun, William Boyd
System: The UNT Digital Library
The Effects of Anxiety on the Performance of Collegiate Golfers in Competitive and Non-Competitive Situations (open access)

The Effects of Anxiety on the Performance of Collegiate Golfers in Competitive and Non-Competitive Situations

The purposes of the study were to provide additional information concerning the relationship of Competition Trait Anxiety, State Anxiety, and Performance in collegiate golfers under non-competitive and competitive field settings. Subjects were thirty college males. Data were analyzed by a three-way analysis of variance with repeated measures. Conclusions of the investigation were (1) low-Competition-Trait-Anxious golfers performed better and exhibited lower levels of state anxiety than high-and moderate-Competitive-Trait-Anxious golfers in competitive and non-competitive settings; (2) collegiate golfers exhibit higher levels of state anxiety in competitive versus practice settings; and (3) there was a significant relationship between SCAT and pre-competitive state anxiety.
Date: May 1980
Creator: Genuchi, Marvin C.
System: The UNT Digital Library
The Effects of Relaxation and Imagery on Karate Performance (open access)

The Effects of Relaxation and Imagery on Karate Performance

The present investigation attempted to determine whether imagery combined with relaxation (VMBR) facmlitated karate performance more effectively than either imagery or relaxation alone. Each subject (N=30) was randomly assigned to either a VMBR, relaxation, imagery or placebo control condition. Trait anxiety tests were administered at the beginning and the end of the six week test period. Performance tests were administered at the final class period along with precompetitive state anxiety. Trait anxiety results indicated a reduction in trait anxiety for all groups. State anxiety results indicated that the VIYBR and relaxation groups exhibited less state anxiety than the imagery and control groups. Performance results produced a main effect only for sparring with the VMBR group exhibiting better performance than all other groups.
Date: May 1981
Creator: Seabourne, Thomas G.
System: The UNT Digital Library
Psychobiological and Pacing Characteristics of Field Tested Endurance Performance (open access)

Psychobiological and Pacing Characteristics of Field Tested Endurance Performance

This study investigated the psychobiological and pacing characteristics of the 1.5 mile run. Sixty-six males (18-27 years) performed the run, and were monitored for ratings of perceived exertion, heart rate and split times. The perceived exertion values increased in a near-linear fashion inconsistent with other measures, and thus are not considered a supportable indicator of physiological performance during the run. Pace was characterized by an initial sprint that slowed to a near-steady pace and concluded with a final sprint. The initial and final sprints were most highly related to the variance of performance time. Initially, heart rate accelerated greatly. This acceleration slowed, ending in near-maximum heart rates. The data suggested that performance may rely heavily upon anaerobic mechanisms, and that variance in previously reported correlational analyses of VO2max and 1.5 mile run performance times may be somewhat due to anaerobic mechanisms.
Date: May 1981
Creator: LaCroix, James Scott
System: The UNT Digital Library
A Study Comparing the Effects of Organized and Nonorganized Play on the Self-Concepts of Five, Six and Seven Year-Old Children (open access)

A Study Comparing the Effects of Organized and Nonorganized Play on the Self-Concepts of Five, Six and Seven Year-Old Children

This study investigated the self-concepts of five, six, and seven year old children after participation in organized and nonorganized play programs. The subjects were sixty boys and girls participating in Little League Tee-Ball programs and sixty boys and girls participating in the City Playground Program in the Fort Worth, Texas, area during the 1979 spring and summer season. The instrument used to measure self-concept was the Purdue Self-Concept Scale, Results indicated that the type of organization has little effect upon the self-concept of the children in this study.
Date: May 1981
Creator: Perry, Kaye
System: The UNT Digital Library
A Study of Lean Body Mass in Estimating Basal Metabolic Rate (open access)

A Study of Lean Body Mass in Estimating Basal Metabolic Rate

The primary purpose of the study was to determine if measured LBM could be used as a more powerful predictor of BMR than could surface area (SA) as calculated by the formula of DuBois and DuBois (1916). It was also of interest to develop a prediction equation for BMR using multiple regression analysis. Data from 82 women and 76 men were included in the study. Pearson product-moment correlations indicated that LBM was a better predictor for BMR than SA on either of the principal SA prediction equations, those of Aub and DuBois (1917) and Harris and Benedict (1919). Age, sex, and fat weight were not found to contribute significantly to prediction when included by multiple regression analyses. Linear equations for BMR as a function of LBM were developed for each sex. Tables based on these equations were also generated as a quick reference for clinicians.
Date: May 1985
Creator: Lachenbruch, Charles
System: The UNT Digital Library
Relationship Between Ventilation and Oxygen Uptake at 40% And 85% of Peak Oxygen Uptake in 18-35-Year-Old Women Using the Arm Crank Ergometer (open access)

Relationship Between Ventilation and Oxygen Uptake at 40% And 85% of Peak Oxygen Uptake in 18-35-Year-Old Women Using the Arm Crank Ergometer

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.
Date: May 1988
Creator: Zervopoulos, Peter C. (Peter Cosmas)
System: The UNT Digital Library
Ground Reaction Forces and Ankle and Knee Moments During Rope Skipping (open access)

Ground Reaction Forces and Ankle and Knee Moments During Rope Skipping

Ground reaction force (GRF) data collected and synchronized with film data to determine peak GRF and calculate moments about ankle and knee during rope skipping. Two, five minute conditions were analyzed for 10 subjects. Condition 1 was set rate and style. Condition 2 was subjects' own rate and style. Means and standard deviations were reported for peak GRF, ankle and knee moments. One way ANOVAs reported no significant difference between conditions for variables measured. Efficiency and nature of well phased impacts during rope skipping may be determined by combination of GRF, similarities in magnitude and direction of joint moments, and sequencing of segmental movements. Technique and even distribution of force across articulations appear more important than magnitudes of force produced by given styles.
Date: May 1989
Creator: Chinworth, Susan A. (Susan Annette)
System: The UNT Digital Library