This thesis aimed to establish why the incidence of a V02-plateau is typically high (>80%) for a discontinuous test but not for a continuous test, how treadmill grade influences V02peak and the incidence of a V02-plateau for a speed incremented test, and whether it is possible to develop a continuous protocol for which the incidence of a plateau in the V02-running speed relationship is >80%. Study 1 was a large study that addressed several issues. Each subject (n = 10) completed a discontinuous test (DCT) in which running speed was increased every 3 min, a continuous test in which the speed was increased every 3 min (CT), a ramp test in which the speed was increased every 5 s (5%RT60), and a run to exhaustion at a.speed calculated to elicit 105% V02 peak (105%T). For each test, the treadmill grade was set at 5%, and the sampling period was set at 60 s. Each subject also completed 2 further tests: a ramp test (5% grade) for which the sampling period was 30 s (5%RT30); and a ramp test (60 s samples) for which the treadmill grade was set at 0% (O%RT). The peak V02 (mean ± SD) was higher for the 5%RT60 than for the DCT (59.9 ± 7.9 vs. 57.8 ± 8.1 ml.1 kg·.1 min; p < 0.05), but the incidence of a V02-plateau was higher for the DCT (80% vs. 50%). The incidence of a plateau was also higher for the 5%RT60 than for the O%RT (50% vs. 30%), as was the peak V02 (59.9 ± 7.9 vs. 57.8 ± 7.9 rnl.kg·1.min·1; p = 0.003). The peak V02 was lower for the 105% T than for the 5%RT60, and the difference between the two values was negatively correlated with the duration of the 105%T (r = -0.89, p = 0.001). The incidence of a plateau was lower for the 5%RT30 than for the 5%RT60 (20% vs. 50%); the reason for this appeared to be that the variability in V02 was higher for the 30 s samples. It was concluded that discontinuous tests should not be used for the assessment of V02m", and that factors which influence the variability in V02 might be important determinants of the incidence of a plateau. Study 2 evaluated the effect of sampling period and exercise intensity on the variability in V02. Eight subjects completed 4 runs at -70% V02P" during which 12 samples of expirate were taken over periods 000, 60, 90, or 120 s. In addition, V02 was determined over twelve 30 s periods during runs at -70 and -96% V02Peak (n = 6). The SD for V02 decreased as sampling period increased from 30 to 60 s (1.3 ± 0.7 vs. 0.6 ± 0.2 ml.kg·1.min·1; p < 0.05), but no further decrease was observed as the sampling period increased beyond 60 s. This SD also decreased as exercise intensity increased (1.1 ± 0.2 vs. 0.6 ± 0.3 ml.kg·1.min·1; p = 0.005), such that the SD for 30 s samples taken during the run at -96% was the same as that for the 60 s samples taken at -70% V02Peak (P = 0.96). It was concluded that the only valid approach to defining a V02-plateau is one in which the sampling period decreases as exercise intensity increases. Study 3 evaluated three ramp tests for the assessment of V02max in runners. Each subject (n = 12) completed 3 tests: a constant speed, increasing grade test (lOT); a constant grade, increasing speed test on a level treadmill (0% T); and a constant grade, increasing speed test conducted at a 5% grade (5% T). For each test, the sampling period decreased as the exercise intensity increased and the individual V02 data were fit to both a linear model and a (two-piece) plateau model. For each test, the SEE was lower for the plateau model than for the linear model (p < 0.0005) and a V02-piateau was observed in >90% of subjects. However, V02max, was higher for the 5%T (64.0 ± 4.7 ml.kg·1.min·1) than for the O%T (62.6 ± 4.6 rnl.kg·1.min·1), and higher still for the lOT (65.1 ± 4.3 ml.kg·1min·1) (p < 0.05). It was concluded that whilst an upper limit for V02 is typically reached when trained runners perform a treadmill ramp test, the V02 at which this limit is reached depends on the conditions under which the test is performed.

This study investigated the technique of the individual, using an integrated biomechanical approach, to assess injury potential and performance. The effects of five neoprene athletic supports were investigated for the cricket bowl and javelin throw. A significant improvement in distance thrown and an increase in linear speed of body segmental movements were found for a lumbar support belt during the javelin throw. A two-handed overhead throwing activity was designed to investigate the effect of this lumbar support belt during the hyperextension - flexion movement of the torso. Significant differences in the distances thrown and segmental timing during the belt condition were found for both novice and experienced athletes. An integrated approach (three-dimensional cinematography, ground reaction forces and electromyography) was then used to analyse the effect of this lumbar support belt during the delivery phase of both sporting activities. The rate at which the torso uncoiled, (the relative peak shoulder to peak hip speed) was found to be significantly different during the belt condition for both activities. The results of these experiments suggest that the lumbar support belt enabled a more efficient transfer of speed to the upper body. A significant improvement in distance thrown during the lumbar support belt condition was found for the javelin throw.

Current techniques of rearfoot alignment measurement have been reviewed and a new clinical technique of rearfoot measurement in weight bearing stance has been developed. This technique was validated by radiographic and cadaveric anthropometric studies. The relationship between a central heel bisection line and the underlying bone structure was investigated, and showed that the heel bisection line was coincident with the centre of the x-ray image of the calcaneus at its upper margin, but appeared to be skewed to the lateral side of the image of calcaneus (to 40% of its width) at its lower margin. A cadaveric study confirmed that this appearance arose as a result of a calcaneal tubercle that is larger medially than it is laterally. Reliability of rearfoot measurement was investigated and showed good repeatability (within the 0.5" resolution of the instrument) when made by an experienced podiatrist, with intratester repeatability of 0.93 and 0.95.

No description available.

Thesis (M.Sc.)--York University, 2006. Graduate Programme in Kinesiology and Health Science. / Typescript. Includes bibliographical references (leaves 75-112). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://proquest.umi.com/pqdweb?index=2&did=1324366891&SrchMode=1&sid=4&Fmt=2&VInst=PROD&VType=PQD&RQT=309&VName=PQD&TS=1194985810&clientId=5220

Thesis (PH.D.) -- Syracuse University, 2007. / "Publication number AAT 3281752"

Thesis (M.P.H.)--University of Wisconsin--La Crosse, 2009. / Includes bibliographical references.

Thesis (Ed. D.)--West Virginia University, 2005. / Title from document title page. Document formatted into pages; contains vii, 115 p. Includes abstract. Includes bibliographical references (p. 76-82).

Thesis (M.S.)--University of British Columbia, 2002. / Includes bibliographical references (leaves 52-54).

The imidazole dipeptides (ImD); anserine (Ans), carnosine (Cam) and balenine, have been shown to be effective at functioning as H+ ion buffers, with Carn being particularly effective within the physiological pH range. Therefore ImD have been reported to be beneficial to athletes exercising at high intensities, where the activity results in the production and accumulation of H+ ions within skeletal muscle. It has also been hypothesised that these compounds may also be beneficial in reducing the morbidities related to ageing, such as Alzheimer's disease. Humans store ImD in the form of Carn and not as anserine or balenine. However, within the human body Carn production is limited by the ability to degrade uracil in the liver, with 3-alanine being the limiting factor. Therefore the content of the diet has a substantial impact on the level of Carn within human skeletal muscle. This thesis aimed to investigate the variability in ImD with age and in subjects from different geographical locations. The effect of ageing on the muscle content of the ImD was demonstrated through the use of a murine model, where increased age was accompanied with a 45% decline in the ImD levels measured in the tibialis anterior of 60wk old senescence-accelerated male mice (Chapter 9). This is supported by further work (Chapter 14) which showed that elderly European subjects exhibited lower levels of carnosine in the vastus lateralis compared to younger European subjects (15.6mmol·kg-1 dm and 22.4mmol·kg-1 dm respectively). However, in Korean elderly subjects no decline was observed (21.5mmol·kg-1 dm), and this could potentially be explained by different dietary habits, with the elderly Korean subjects consuming larger amounts of protein-rich foods than their European counterparts. Analysis was made of the variation in the carnosine content of the vastus lateralis in subjects from differing geographical locations, and subsequently different cultural diets with varying meat contents, and showed that dietary intake of a diet habitually rich in the ImD could potentially 'over-ride' the decline seen with age in subjects who 'reduce' their meat intake.