PURPOSE: The purpose of this study was to compare the effects of a high volume isokinetic intervention on lower body strength and inflammation, as well as markers of muscle damage in the subsequent 48 hours between younger and middle-aged men. METHODS: 19 healthy, recreationally trained men were randomly assigned to two groups, younger adults (YA: 21.8 ± 2.0 y; 90.7 ± 11.6 kg; 21.5 ± 4.1 % body fat), or middle-aged adults (MA: 47.0 ± 4.4 y; 96.0 ± 21.5; 24.8 ± 6.3 % body fat). Both groups reported to the human performance laboratory (HPL) on four separate occasions. On the first visit (D1), anthropometric assessment, as well as a familiarization session with the isokinetic dynamometer, was performed. A muscle damaging protocol (HVP) was performed on the second visit (D2) consisting of 8 sets of 10 repetitions at 60°·sec-1 on the isokinetic dynamometer. An assessment protocol (AP) was performed to assess performance decrements between the YA and MA groups. For this protocol, a maximal voluntary isometric contraction (MVIC) was performed, as well as 3 isokinetic kicks at 2 different speeds (240°·sec-1 and 60°·sec-1). For the MVIC, values for peak torque (PKT), average torque (AVGT), rate of torque development at 100 ms (RTD100), and 200 ms (RTD200) were recorded. For the isokinetic kicks at 240°·sec-1 (ISK240) and 60°·sec-1 (ISK60), values were also recorded for peak torque (PKT), average torque (AVGT), as well as peak power (PP), and average power (AVGP). The AP was performed before the HVP (BL), immediately after the HVP (IP), 120 minutes after the HVP (120P), as well as one (24H) and two (48H) days following the HVP. Blood draws were also taken at BL, IP, 24H, and 48H, as well as 30 minutes (30P), and 60 minutes (60P) following the HVP to assess circulating levels of creatine kinase (CK), myoglobin (Mb), c-reactive protein (CRP), and interleukin 6 (IL-6). Ultrasound assessment was also performed at BL and IP as well to assess changes in muscle morphology as a result of the intervention. Performance, blood, and ultrasound markers were analyzed using a repeated measures ANOVA to observe between group comparisons for all of the outcome variables. RESULTS: There were no group differences observed for isometric or isokinetic peak torque or average torque, nor were there differences in isokinetic peak power or average power between the two groups as a result of the intervention. There were, however, differences in the pattern for rate of torque development at 100 ms and 200 ms between the two groups. RTD 100 was decreased at IP and 48H in YA, with MA showing decreases at IP, but also 120P and 24H unlike YA. RTD200 was decreased at all time points in YA, while MA was decreased at IP, 24H, and 48H, but not 120P. For markers of muscle damage and inflammation, there were no differences in the response of Mb, CK, CRP, or IL-6 between groups. CONCLUSIONS: Age does not appear to be a driving factor in the inflammatory or muscle damage response from a high volume isokinetic intervention. Though changes in peak torque and average torque from a high volume isokinetic intervention do not seem to differ between younger and middle-aged adults, the rate of torque production at 100ms and 200ms is different between groups. This suggests that while recovery to average or maximal strength after an exercise bout may not be affected greatly by age, the rate of neuromuscular recovery from exercise may be primarily affected by other factors such as training status.

<p dir="ltr">These pre-clinical data suggest elevated AGE, as seen with diabetes, could impact tendon healing <i>in vivo</i>. If, with a large sample size, we find that RAGE inhibition limits the impact of AGEs on tendon healing, then local RAGE inhibition could be a viable therapeutical approach to improve tendon properties in individuals with elevated AGEs. While additional work is needed to define the role of RAGE in regulating tendon properties, our preliminary results provide a premise for detailed mechanistic studies. Our initial work in mice provides a framework to evaluate the potential of lowering serum AGEs to improve tendon healing.</p>

<p>The extent of skeletal muscle hypertrophy in response to resistance training is highly variable in humans. To explain the nature of this variability, we focused on the myogenic stem cell population, the satellite cell (SC) as a potential mediator of hypertrophy. Twenty-three males (aged 18-35yrs) underwent 16wk of progressive, whole body resistance training, resulting in changes of 7.9%±1.6 (range of -1.9 – 24.7%) and 21.0%±4.0 (range of -7.0 to 51.7%) in quadriceps volume and myofibre cross-sectional area (CSA) respectively. The SC response to a single bout of resistance exercise (80% 1RM), resulted in an expansion in type one fibre associated SC (MHCI-SC) content of 43.7%±10.4 24h post-exercise pre-training, that shifted, post-training, to an increase in type two fibre associated SC (MHCII-SC) content of 47.6%±21.2 72h post-exercise. Analysis of individual SC responses revealed a correlation between the relative change in MHCII-SC content between 24-72h pre-training and the percentage increase in quadriceps lean tissue mass assessed by MRI (r=0.663, p=0.001). The proportion of SC co-localized with MSTN decreased progressively in the acute time-course following exercise and correlated with SC expansion between Pre-24h (r=0.563, p=0.012) and Pre-72h (r=0.454, p=0.045) in the pre- and post-training time-courses. In conclusion, the SC response to exercise appears to become more specific with training; while individual capacity to invoke the SC response is predictive of training induced muscular hypertrophy and may be limited by the degree of MSTN co-localization.</p> / Master of Science (MSc)

Traditional approaches to exercise testing in children may not provide the most appropriate measures of a child's physiological responses to exercise, partly because they do not reflect children's normal intermittent activity patterns. The measurement of the rate and magnitude of change of oxygen uptake to dynamic exercise, oxygen uptake kinetics (V02 KINETICS provides an alternative approach to exercise testing. A submaximal, intermittent, pseudo-random binary sequence (PRBS) exercise test to measure V02 KINETICS may provide a useful method of measuring the metabolic responses of children to exercise. Traditional methods used in the analysis of V02 KINETICS require the fitting of explicit models in order to characterise the data. These models have not however been validated for use in children. As the responses to the PRBS protocol are analysed in the frequency domain, explicit models and their physiological correlates are not required to characterise the data. Another potential problem in the measurement of V02 KINETICS in children are the small work rate changes that can be employed to stimulate the exercise response whilst constraining the test to the aerobic range. In respiratory gas measurement, breath-by-breath variability (noise) can be large in comparison to the magnitude of the metabolic response and this signal noise can obscure some characteristics of the response. The aim of the study was to develop appropriate measurement techniques to reduce the effects of breath-by-breath variability and to apply the techniques to the measurement of V02 KINETICS in children. The main experimental study compared the V02 KINETICS of children with those of adults. Ten children (3 females) in the age range 8 to 13 and twenty adults (10 females) in the age range 20 to 28 years completed a PRBS test to measure V02 KINETICS and an incremental ramp protocol on a cycle ergometer (Bosch 550 ERG) to establish V02 MAX, T VENT and delta efficiency. Breath-by-breath respiratory gas analysis was undertaken using a respiratory mass spectrometer (MGA1100). Estimates of alveolar gas exchange were made using the algorithm of Beaver et al. (1981) and a post hoc value of an effective lung volume was calculated to minimise the breath-by-breath variability. A cross-correlation technique (CC) was used to filter out the effects of anomalous (nonphysiologic) V02 responses recorded during the PRBS protocol. Subsequent Fourier analysis of the auto-correlation and CC functions provided a description of V02 KINETICS in the frequency domain in terms of amplitude ratio and phase delay over the frequency range of 2.2-8.9mHz. At each of the frequencies assessed amplitude ratio was higher in children (P<0.001) than in either of the adult groups. Phase delay was also significantly shorter in children compared to adults males (P<0.01) and adult females (P<0.001) but this effect was not identifiable at any specific frequency. Maximal oxygen uptake was not significantly different in adult males (42.5 ml"kg "min) and children (44.7 ml-kg'-min') but was lower in adult females (36.9 ml"kg "min) than adult males (P<0.01) and children (P<0.001). Ventilatory threshold (% V02 MAX) was not different between groups. Delta efficiency was significantly lower in children than adult males (P<0.05) and adult females (P<0.01). These results support the contention that there are maturational differences between adults and children in the metabolic processes involved in the utilisation of oxygen during physical activity. It has been argued, theoretically, that in adults the control of V02 KINETICS is driven by ATP demand in the skeletal muscle. As the mitochondria] capacity and the concentration of oxidative enzymes is higher in children than in adults it is likely that the controlling factor(s) for V02 KINETICS in children also relates to some aspect of peripheral metabolism. It is suggested that the PRBS protocol, with appropriate noise reduction techniques, is considered a suitable method for investigating the metabolic responses of children to dynamic exercise.

This thesis examines the media representations of Chien-Ming Wang, a Taiwanese baseball player who played for the New York Yankees, in American and Taiwanese print media from 2005 to 2009. Wang had been attracting media attention in both the United States and in Taiwan during the time because of his athletic performance and dual identities in the two places. The results show that the Taiwanese media usually placed heavy emphasis on his national identity, making him one of the most high-profile athletes in Taiwan. On the other hand, as a foreign player and an Asian athlete, his racial identity was sometimes the focus of the American media. While he had been generally portrayed in a positive way, his Asian identity is still well-scrutinized. I argue that his media representations in the United States fit the model minority discourse which remains the typical perception in the US, meaning that stereotypical characteristics of Asians or Asian Americans are emphasized or overrepresented.

Current industry practices promote therapeutic use of pulsatile stimulation plates to increase muscle mass, strengthen bone density, reduce stress, and improve overall athletic performance of horses. The first objective of this study was to investigate the effect of vibration stimulation on muscle thickness of the extensor carpi radialis, extensor digitorum longus, gluteus medius, longissimus lumborum, semitendinosus, supraspinatus, and longissimus thoracis, as well as circumference and cross-sectional area of the extensor carpi radialis and extensor digitorum longus. The second objective was to evaluate changes in nutrient foramen thickness, circumference, and area, as well as dorsal cortical thickness of the left third metacarpal in response to vibration stimulation exposure over 56 d. Increases in thickness of the topline muscles and improvement of nutrient foramen parameters of treatment horses give evidence to conclude that vibration stimulation may be a viable therapeutic treatment for stock-type horses on stall rest.

The physiological responses to upper-body exercise (UBE) are well established. Few published studies, however, have attempted to elucidate the mechanical ventilatory responses to UBE. There is empirical evidence that respiratory function may be compromised by UBE during which the ventilatory and postural functions of the ‘respiratory’ muscles may be exacerbated. Therefore, the aims of this thesis were: 1) to characterise the mechanical-ventilatory responses to UBE in healthy subjects; 2) to explore the putative mechanisms that underpin the respiratory responses to UBE; and 3) to assess whether the mechanical-ventilatory stress imposed by UBE induces contractile fatigue of the respiratory muscles. Compared to lower-body exercise (LBE; leg cycling) at ventilation-matched work rates, UBE (arm-cranking) resulted in constraint of tidal volume, higher respiratory frequency, and greater neural drive to the respiratory muscles. Furthermore, end-expiratory lung volume was significantly elevated during peak UBE compared to LBE (39 ± 8 vs. 29 ± 8% vital capacity, p < 0.05) and was independent of expiratory flow limitation. In assessing the influence of cadence on cardiorespiratory function and respiratory mechanics, submaximal arm-cranking at high cadence (90 rev.min-1) induced significantly greater cardiorespiratory stress, a trend towards elevated intra-thoracic pressures and significantly greater perceptions of dyspnoea than at low cadence (50 rev.min-1). Furthermore, there was a greater prevalence of locomotor-respiratory coupling at high cadences (p < 0.05), suggestive of greater antagonistic loading of the thoracic muscles, likely the result of static postural contractions. Finally, there was objective evidence of abdominal muscle contractile fatigue in response to severe- but not heavy-intensity UBE. Specifically, there was a 22% decrease in gastric twitch pressure from pre- to post-exercise in response to magnetic stimulation of the thoracic nerves (p < 0.05). However, there was limited evidence of exercise-induced diaphragm fatigue, as assessed using magnetic stimulation of the phrenic nerves (p > 0.05). In conclusion, mechanical-ventilatory function may be compromised during UBE due to complex interactions between thoracic muscle recruitment, central neural drive and thoracic volume displacement. This thesis presents novel findings which may have important functional implications for clinical populations who report breathlessness during activities of daily living that involve the upper-body, as well as for athletes engaged in upper-body sports.

A dissertation submitted to the Faculty of Medicine, University of the Witwatersrand, Johannesburg for the degree of Master of Science in Medicine. / A study was undertaken to ascertain whether a low intensity, long term home walking exercise programme could produce physiological changes in patients with chronic obstructive pulmonary disease (COPD). Subjective psychological effects of such a programme were also evaluated. (Abbreviation abstract) / AC2017

"May 2002." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (p. 142-163). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. Ann Arbor, MI : ProQuest Information and Learning Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

The purposes of this dissertation were to examine the effect of a protein and carbohydrate recovery beverage versus a placebo on weightlifting performance, its effect on muscle morphological changes and specific muscle protein accretion. The following are major finding from the dissertation: 1) Protein and carbohydrate recovery supplementation does not appear to have influence on performance measure in trained weightlifters. This finding may be associated with the short-term nature of this study and the trained population used. 2) Compared with placebo, a protein and carbohydrate beverage provided greater benefits on cross sectional area of type I and type II muscle fibers. Additionally, the block periodization protocol incorporating phase potentiation improved cross sectional area of both groups compared to baseline. 3) Finally, protein and carbohydrate supplementation provided greater benefits on total mTOR and myosin heavy chains 6 & 7. These findings indicate that a protein and carbohydrate beverage provide greater benefits compared with a placebo on cellular signaling, myosin heavy gene expression and muscle fiber increases in trained weightlifters. Improved cross sectional area and increased myosin heavy chains indicate positive adaptations to resistance training combined with supplementation and may indicate improved skeletal muscle qualities necessary for increased power output. The mTOR pathway is the master regulator of cellular growth and increases in total mTOR indicate a greater proclivity for cellular growth and greater activity resulting from resistance training may increase synthesis and accretion of muscle contractile proteins. This dissertation highlighted several benefits of recovery supplementation, however further longitudinal studies utilizing block periodization and well-trained athletes are necessary to fully elucidate benefits for strength and power athletes.