<p>Three experiments are reported that examined the lnfluence of prior judgements on implicit and expliclt tests of memory in gymnastic judging. The rationale was that if gymnastlc Judging ls affected by the memory for prior eplsodes, then the accuracy of judgements should change as a result of the prior episode. The results of Experiment 1 revealed that perceptual judgements dlffered as a functlon of an item's relationship between the study phase and the perceptual test phase. Moves that had the same performance ln both phases resulted ln the hlghest level of accuracy (M = 79%). New moves were less accurate (M = 75%). The lowest level of accuracy was achieved for items where the performance was altered between study and the perceptual test (M = 72%) . Similarly, recognition judgements differed as a functlon of an item's relationship between the study phase and recognition test phase. Novlce and expert Judges revealed similar memory lnfluences for perceptual and recognition Judgements (Experiment 1). Memory influences were reduced, but still evident when subjects were given prior knowledge of these effects and procedural changes were adopted (Experiment 2). Spacing of repetitions dld not enhance prior processlng effects of perceptual Judgements, but superior retention was noted for spaced repetitions in the recognition test phase (Experiment 3). These findings are discussed in terms of memory influences on subjective experience and the practical implications of Judges' exposure to an athlete's performance prlor to competition.</p> / Master of Science (MS)

<p>It is known that human skeletal muscle has several fiber types, each with a different metabolic and physiological profile. It is not known whether there are different ultrastructural characteristics within each fiber type which may account for the different contractile properties. The purpose of this study was to examine the relationship between fiber type and ultrastructural characteristics.</p> <p>Needle biopsies were obtained from the right vastus lateralis of five healthy males. According to the method described by Alway et al (1980), the tissue was prepared for electron microscopy and fiber types were identified based on their myoglobin content. Three non-overlapping electron micrographs were taken from the interior of each fiber under a Philips 300 electron microscope, and 50 type I and 50 type II fibers were examined from each subject. The constituents which were studied included: myofibrillar protein, mitochondria, cytoplasm, lipid and sarcoplasmic reticulum (SR). Volume densities were calculated for each constituent by means of a l68-point counting technique from electron micrographs projected onto a screen.</p> <p>The results indicated that type I fibers were significantly greater with respect to mitochondrial volume density and lipid volume. However type II fibers had significantly greater myofibrillar volume densities and sarcoplasmic reticulum volume density (by approximately twofold). Fiber areas were also greater in type II than type I fibers while myosin packing density did not differ between fiber types.</p> <p>It was concluded that SR and myofibrillar protein ultrastructural differences between fiber types may be important factors in determining twitch contraction properties and tension production for type I and II fibers. Finally, differences in mitochondrial volume density may be important in determining fatiguability of fiber types.</p> / Master of Science (MSc)

<p>The effects of a 12-week physical conditioning program on cardiorespiratory responses and the subjective assessment of work intensity (RPE) during exercise in healthy, middle-aged females and females with coronary heart disease (CHD) were studied. A physical conditioning program was developed for healthy, middle-aged females and females with CHD using an exercise prescription based on current practice in middle-aged males with and without CHD. The progress included cycle ergometer exercise prescribed at 65-75% of maximal VO₂ for 30-45 minutes 3 times per week.</p> <p>Six cardiac females (aged 40 to 57 years) and 9 healthy females (aged 44 to 52 years) started the program. The cardiac females had a significantly lower maximal work capacity, VO₂ and VCO₂ (p<0.05) than the healthy females. Measures of other variables were similar in the two groups. Following physical conditioning the healthy females demonstrated a significant increase in maximal PO(27.6%), VO₂ (15.9%), VE (23.9%) and VCO₂ (17.8%); a significant decrease in HR (10.5%), SBP (7.1%), RPP (17.5%), VCO₂ (12.0%) and RPE (33.1%) at a standard submaximal PO; and a significant decrease in steady state VO₂ (6.7%), Qc (13.4%) and HR (9.4%) (p<0.05). No changes were observed in other variables. Since only 3 cardiac females completed the 12-week program, they were treated as case studies. These 3 cardiac females showed considerable variation in their cardiorespiratory responses to physical conditioning but each exhibited a reduction in RPE at submaximal power outputs following physical conditioning. It was concluded that the physical conditioning program; (a) improved cardiorespiratory functioning, and reduced perceived exertion, during exercise in the healthy, middle-aged females; and (b) was effective as a mode of psychophysical rehabilitation, but not necessarily as a mode of physiological rehabilitation, for the females with CHD.</p> / Master of Science (MSc)

<p>The present study was undertaken to investigate the mechanism underlying the observation that the maximal voluntary strength of the two legs acting together or bilaterally in isometric leg extension was less than the summed unilateral (sum of the left and right legs tested separately) strength. Observations were made on this phenomenon under both isometric and concentric contraction conditions by testing young adult males performing unilateral and bilateral leg press contractions on a modified isokinetic dynamometer.</p> <p>Electromyographical evidence indicated that there was a lesser activation of motor units in bilateral contractions, as compared to unilateral, under isometric conditions and at a low and high concentric velocity. To determine whether a particular type of motor unit was being activated to a lesser extent in bilateral contractions, two physiological parameters of unilateral and bilateral contractions were compared: the strength-velocity relation and fatigability. This investigative method was based on the known physiological differences between the motor unit types; namely fast-twitch (FT), type two motor units have a faster twitch contraction time, greater force output at high velocities of shortening and lesser resistance to fatigue than the slow-twitch (ST), type on units.</p> <p>Results showed a greater relative decline in the strength of bilteral contractions as the velocity of contraction was increased through a range from 0°/s to 424°/s (0 to 7.40 radians/s). The bilateral to summed unilateral strength ratio (B/U ratio) decreased from 0.91 under isometric conditions to 0.51 at the highest test velocity. Lesser fatigability was found in the bilateral condition in a 100 consecutive concentric contraction fatigue test. These results provided complementary evidence for the conclusion that FT motor units were active to a lesser degree in bilateral contractions.</p> / Doctor of Philosophy (PhD)

<p>This study was designed to compare the effects of two weight training systems, the Interval Circuit and High Intensity systems on muscular strength, cardio-respiratory endurance, girth measures and self-concept of high school boys.</p> / Master of Science (MSc)