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Item Insulin resistence in adult type-2 diabetic skeletal muscle : the effects of exercise and dietary-protein induced skeletal mucscle plasticity controlling microvascular blood flow and glucose transport : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy (Sport and Exercise Science), Massey University, Wellington, New Zealand(Massey University, 2019) Peeters, WouterIntroduction: Insulin-stimulated skeletal muscle glucose uptake is impaired in Type-2 Diabetes Mellitus (T2DM). Insulin resistance leads to reduced skeletal muscle microvascular function and insulin signalling. The purpose of the thesis was to evaluate and compare the effect of chronic intake of a novel keratin-derived protein (WDP) and whey protein, in conjunction with exercise training, on glucose homeostasis and skeletal muscle glucose uptake in T2DM. Methods: In a randomized, double-blinded clinical trial, thirty-five men and women with T2DM completed a 14-week exercise intervention but were randomly assigned to ingest either post-exercise and evening supplements of 20 g WDP-whey protein blend (WDP, n = 11), whey protein (WHEY, n = 12) or isocaloric maltodextrin (CON, n = 12). Before and after the intervention, fasting HbA1c and glucose clearance rate (GCR) during a hyperinsulinaemic isoglycaemic clamp were measured. Insulin-stimulated skeletal muscle blood flow and volume were measured during the clamps via near -infrared spectroscopy. Muscle from the m. vastus lateralis was harvested prior to and at 1-h into the clamps to determine skeletal muscle insulin signalling proteins. Results: Substantially bigger improvements in WDP compared to WHEY or CON were found for GCR, insulin-stimulated GLUT4 translocation and insulin-stimulated blood flow. Fasting eNOSser1177/eNOS possibly increased in WDP and WHEY compared to CON. Capillarization improved in all groups with unclear differences between groups. Conclusion: WDP-whey blend ingestion during 14 weeks of exercise training improved skeletal muscle plasticity and some processes involved in insulin-stimulated glucose uptake to a greater magnitude compared to whey protein or an exercise-only group in T2DM. WDP protein holds the potential to be an additional therapy to exercise as a treatment in T2DM.Item The effect of 10 weeks of peri-training whey protein supplementation on systemic, metabolic, and skeletal muscle molecular responses in Type-2 diabetes : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy (Sport and Exercise Science), Massey University, Wellington, New Zealand(Massey University, 2017) Gaffney, KimIntroduction: Type-2 diabetes (T2D) is a modern global epidemic associated with multiple health complications and economic burden. Exercise improves glycaemic control in populations with T2D with greater insulin sensitivity, muscle hypertrophy, and reduced emotional distress as possible mediators. Milk protein supplementation has been shown to produce similar benefits, raising the potential of an adjunct therapy. Therefore, the primary purpose of the thesis was to determine if whey-protein supplementation can promote skeletal muscle plasticity associated with improved glycaemic control in exercising men with T2D. Secondary aims were to determine if improvements in functional capacity and glycaemic control led to better mood and quality of life. Methods: In a randomized, double blind clinical trial, 24 non-insulin dependent middle-aged men with T2D were allocated to a pre- and post-training whey-carbohydrate (20 grams-10 grams) supplement or isocaloric carbohydrate-only control. Participants completed 45 high-intensity endurance and resistance exercise sessions over 10 weeks. Insulin sensitivity was determined from glucose disposal rates (GDR) during a euglycaemic insulin clamp, with fasting blood glucose concentration (FBG) and the homeostatic model of assessment of insulin resistance (HOMA-IR) providing secondary measures of glycaemic control. Insulin-mediated haemodynamics; microvascular blood flow (mBF) and microvascular blood volume (mBV) were assessed at the vastus lateralis (VL) muscle via near-infrared spectroscopy. VL muscle biopsies were used to determine capillarity, intramyofibrillar mitochondrial and lipid density, citrate synthase (CS) and cytochrome c oxidase (COX) activity, and mRNA content of angiogenic and mitochondrial markers: eNOS, VEGFA, VEGFR2, PGC1-α, CS, NRF1. Aerobic capacity (VO2peak), strength (1-repetition maximum), VL muscle and subcutaneous adipose thickness, and survey-rated mood and quality of life (DASS42; SF-36) were also assessed. Results: There were substantial increases in GDR (27.5%; 90%CI 1.2%, 60.7% and 24.8%; -5.4%, 64.8%), capillarisation (24.5%; -0.1%, 55.0 and 26.3%; 1.9%, 56.6%), and mitochondrial density (24.3%; 13.8%, 35.8% and 26.7%; 16.8%, 37.5%) in the control and whey groups respectively, with no group differences. Lipid density, COX enzyme activity, VL muscle thickness, VO2peak, 1RM strength, mood, and quality of life were also substantially increased with no group differences. Exercise training had no effect on microvascular haemodynamics; however, whey supplementation produced likely and possible improvements in mBV (16.8%; -4.3%, 42.6%) and mBF (5.9%; -3.7%, 16.3%) respectively at rest and likely improvements in both mBV (17.5%; -3.7%, 43.5%) and mBF (10.2%; 0.3%, 21.1%) under insulin-stimulated conditions. Regression analysis of the pooled 10-week change outcomes showed a positive relationship between the change in lipid density and the change in GDR (r = 0.29); negative associations between basal mBV and FBG (r=.27) and HOMA-IR (r=.30); a negative association between basal mBF and HOMA-IR (r=.48); and a positive association (r = 0.39) between the total DASS score and the change in FBG. Conclusion: Peri-training whey protein supplementation elevated microvascular blood kinetics in middle-aged men with T2D; but did not accentuate the substantial improvements produced by the intense mixed-mode exercise training on tissue and cellular remodelling, insulin sensitivity, glycaemia, exercise capacity, mood or quality of life. The findings support the use of adjunct whey protein supplementation for elevating microvascular blood kinetics in populations with T2D, an outcome that could potentially improve the treatment of vascular diseases where microcirculation contributes to disease pathology and therefore warrants further exploration. The observation that myocellular lipid density was increased by intense exercise training and not detrimental to insulin sensitivity supports recent evidence that lipid accrual may be a favourable adaptation to exercise in populations with T2D.Item A pilot study : high intensity intermittent training to combat chronic stress in the New Zealand Police : a Master's thesis presented in partial fulfilment of the requirements for the degree of Masters of Sport and Exercise at Massey University, Wellington, New Zealand(Massey University, 2016) Kurtovich, Rebecca JaneBackground: Stress is increasingly being reported to be associated with immunosuppression, disease progression and psychological illness (Sergerstrom & Miller, 2004). Police are considered to be employed in a highly stressful occupation and due to this are at a heightened risk for developing negative chronic stress related disorders (de Terte & Stephens, 2014). There are known strategies to combat stress such as exercise. However, in moderately active individuals a more vigorous exercise programme is needed to reduce the effects of stress. High intensity intermittent training (HIIT) could be a potential stress reducing mechanism especially due to its success in treating obesity, weight loss and cardiac issues (Gibala, Little, MacDonald, & Hawley, 2012; Schoenfeld & Dawes, 2009). Aim: To see the effects of HIIT on chronic stress indices in the New Zealand Police. Method: Using three single case studies, this study employed a 10-week HIIT intervention measuring markers of stress such as Perceived Stress Scale scores, cortisol levels and associated blood immune markers at baseline and postintervention. Results: Chronically stressed police officers displayed high perceived stress scale scores and compromised immune functioning due to decreased cortisol secretion and increased eosinophil count. Post-intervention decreased perceived stress, normalised cortisol levels and reduced immune inflammation markers. Conclusion: High Intensity intermittent training decreases perceived chronic stress while also providing further evidence for the relationship between systemic inflammation and mental disease.Item The effect of a child-specific high intensity games intervention on physiological responses in normal weight and obese children : submitted by Nicole Westrupp to Massey University Wellington as a thesis towards the degree of Master of Health Science with Sport and Exercise Science (February, 2013)(Massey University, 2013) Westrupp, NicoleTo date, little is known about the use of child- specific high-intensity games- based exercise to improve body composition, cardiovascular indices, musculoskeletal health, psychological and social well-being. Past research in children has predominantly focused on the effect of laboratory or games based moderate intensity exercise interventions on the aforementioned markers of health (Janssen & LeBlanc, 2010). Therefore, the aim of this investigation is to assess the effect of a 6 week high-intensity games-based intervention on the physiological responses and physical parameters in normal and overweight or obese children aged 8 to 10 years. Twenty eight children were randomized into an exercise group (EX; 9.3 ± 0.9 y, 1.40 ± 0.10 m, 41.0 ± 12.4 kg, 20.5 ± 4.4 kg·m2) and 27 children into a control group (CON; 9.3 ± 0.8 y, 1.40 ± 0.09 m, 39.0 ± 11.3 kg, 19.5 ± 4.1 kg·m2). All participants completed two, pre-intervention (pre-INT) exercise tests on a treadmill i) discontinuous graded exercise test (GXT) to peak oxygen consumption (O2peak) and ii) a submaximal exercise test at running speeds equivalent to moderate (ventilatory threshold [VT]) and heavy (40% delta [difference between O2peak and VT]) intensity exercise for a total of 6 minutes. The EX group took part in 2 x 40 minute high-intensity child-specific games-based exercise sessions per week for 6 weeks. Follow-up assessments identical to the pre-INT were completed thereafter for all participants. The EX group from pre to post intervention (post-INT) demonstrated a significant increase in absolute O2peak and running speed for the GXT test (P < .05); and demonstrated a significant increase in their running speed at VT (7.8 ± 0.9 vs. 8.2 ± 0.8 km·h-1) and 40% delta (9.4 ± 1.0 vs. 9.9 ± 1.1 km·h-1; P < .05) when compared to the CON group. A significant decrease in O2 at VT and 40% delta was also observed for the EX group in comparison to the CON group (P < .05), thus demonstrating an improvement in exercise efficiency. In conclusion, a short duration (6 week) child-specific high intensity games intervention may improve maximal functional capacity and exercise efficiency, independent of body mass in children aged 8 to 10 years. An increase in the oxygen carrying capacity of blood, and capillary and mitochondrial density within the skeletal muscle are potential mechanisms for the aforementioned outcomes. Findings from this study provide important information concerning the practical application of physical activity within school or clinical-based programmes to improve health and physical fitness.Item The effect of seated and supine exercise on executive function in TIA patients and healthy controls : a thesis presented in partial fulfilment of the requirements for the degree of Master of Health Science in Sport and Exercise at Massey University, Wellington(Massey University, 2014) Grigg, Rebecca MaureenPurpose: Exercise is suggested to improve executive function in healthy adults. However, there is limited research in this area on stroke populations. The purpose of this study was to examine the effects of an acute sub-maximal bout of seated and supine exercise on executive function in transient ischemic attack (TIA; minor stroke) patients and an age-matched healthy control group (HC). Methods: Nine TIA patients (7 males, 2 females; 65.1 ± 10.1 y; 85.8 ± 16.9 kg) and fifteen HC participants (13 males, 2 females; 61.5 ± 7.1 y; 84.9 ± 16.3 kg) performed two familiarisation sessions and four laboratory-based exercise protocols on a cycle ergometer. During the laboratory-based exercise tests participants performed two continuous, incremental maximal graded-exercise tests (GXT) to volitional exhaustion; one test was performed on a seated cycle ergometer, the other on a cycle ergometer in a supine position. The two remaining tests were 30-minute sub-maximal exercise tests (Seated and Supine). The Stroop task assessed executive function and was performed prior-to (Baseline), immediately after (Post) and 15-minutes (15-min Post) following the sub-maximal exercise tests. Near infrared spectroscopy (NIRS) was continuously recorded throughout the entire testing protocol to assess changes in total haemoglobin (tHb), oxy-haemoglobin (O2Hb), deoxy-haemoglobin (HHb), and tissue saturation index (TSI). Results: Regardless of exercise modality (Seated cf. Supine) or condition (TIA cf. HC) (P < 0.05), exercise elicited significant improvements in the time to complete the Stroop task (Baseline: 61.3 ± 10.0 s; Post: 58.1 ± 9.4 s; 15-min Post 54.8 ± 9.0 s). There were no changes in the number of correct Stroop answers reported for Seated exercise across each assessment time point (P > 0.05). However, a significant decrease in the number of correct answers was revealed immediately after (Post) Supine exercise which increased 15-minutes after exercise (P < 0.05). There was a significant increase in tHb (-0.6 ± 7.3 cf. 15.6 ± 8.1 %) and O2Hb (-2.3 ± 10.9 cf. 22.2 ± 11.1 %) after exercise (Baseline to Post) which remained significantly higher 15-minutes following exercise regardless of the exercise modality (Seated cf. Supine) or condition (TIA cf. HC) (both P < 0.001). Conclusion: This study showed 30-minutes of sub-maximal exercise in a seated and supine position led to improvements in executive function in TIA and HC participants. Cognitive improvements were observed immediately and 15-minutes after exercise. Possible mediators include increases in cerebral oxygenation and neurotransmitters. These findings may be important for improving executive function, a cognitive domain greatly impaired by stroke. Future research should further investigate the underlying mechanisms by which exercise affects executive function in stroke patients.Item The South Pacific Islands Resist Diabetes With Intense Training (SPIRIT) Study : investigation of obesity markers and morphological, functional and genetic changes in the skeletal muscle : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Health Sciences, Institute of Food, Nutrition and Human Health, College of Health, Massey University at Wellington, New Zealand(Massey University, 2013) Hayat, IrumThe skeletal muscle (SM), the major tissue for disposal of excess blood glucose, plays a big role in development of insulin resistance leading to type 2 diabetes mellitus (T2DM). Lipid accumulation and decline in mitochondrial activity in SM has been observed in people with T2DM. Several studies have demonstrated that exercise has the ability to increase SM lipid oxidation and mitochondrial activity and hence is effective as a treatment strategy for people with T2DM for improving blood glucose control and insulin sensitivity. The SPIRIT study was the first clinical randomised exercise trial involving a cohort of Polynesian New Zealanders with T2DM. The uniqueness of this study is that it is the first clinical trial in Polynesian population with grade 3 obesity (n=18; BMI 43.8 ± 9.5 kg/m2) and T2DM. The SPIRIT cohort underwent 16 weeks of progressive resistance training (PRT) or aerobic exercise (AER) training. The cohort showed no changes in HbA1c levels after 16 weeks of exercise and hence no improvement in their blood glucose control. This was an unexpected result and led to the following hypothesis which underlines this PhD study – ?In skeletal muscle of SPIRIT cohort, metabolic adaptation to exercise is delayed due to metabolic inflexibility?. To investigate this hypothesis, mitochondrial function and morphology, lipid droplet content and changes in gene expression pre and post exercise intervention were examined in the SM. Since the SPIRIT cohort showed no changes in weight, waist circumference and BMI, examination of the concentration of specific obesity markers pre and post exercise training also occurred. Mitochondrial function was examined pre and post 16 weeks exercise intervention by measuring the SM activity of three key mitochondrial enzymes; citrate synthase (CS) involved in Krebs cycle, beta-hydrxoyacyl-CoA dehydrogenase (BHAD) involved in fat oxidation and cytochrome c oxidase (COX) involved in electron transport chain. The PRT cohort showed statistically significant increases in activity for COX (P=0.005) and CS (P=0.007) with very large effect size (2.3 ± 1.3 and 1.8 ± 1.3 respectively). AER exercise led to significant increases in the activity for all three enzymes COX (P=0.01), CS (P=0.03), BHAD (P=0.03) with moderate effect size for both COX and CS activity but very large effect for BHAD (6.7 ± 1.2). For all three enzymes there were statistically significant differences (P<0.05) between the AER and PRT groups. These results demonstrate increased mitochondrial activity and functioning after 16 weeks of PRT or AER exercise.Item Phase two exercise rehabilitation following a cardiac event : the effects of group and individual exercise on psychological well-being, physical status and quality of life : a thesis presented in partial fulfilment of the requirements for the degree of Masters of Health Science in Sports and Exercise at Massey University, Wellington, New Zealand(Massey University, 2011) Green, VenessaA cardiac event has serious consequences for physical and emotional health. The aim of this research was to determine the effects of a 16 week exercise-based cardiac rehabilitation programme for improving physical status, psychological well-being and quality of life. It also aimed to examine whether group based exercise with social interaction is more beneficial for improving psychological status and quality of life among people undergoing cardiac rehabilitation compared to exercising alone. A pilot study was conducted in 2009 with six participants, all of whom took part in the 16 week programme. Based on this pilot work, a number of modifications were made to the study design, assessments and questionnaires. The main study involved 11 cardiac patients who had all experienced a cardiac event, and were recruited from Wellington Hospital or through word of mouth. The study employed a randomized crossover design, with participants acting as their own controls. The 16 week period was divided into 4x4 week blocks. All participants initially completed a four week baseline condition in the Massey Cardiac Rehabilitation Clinic (standard group exercise activities). Half of the participants then completed one of two intervention conditions, either increased social interaction within group exercise, or individual exercise and minimal social interaction. Following the intervention, participants undertook the 4-week baseline again (to washout intervention effects), and then crossed over to the alternative intervention. On commencing the study and at the end of each 4-week condition, participants completed physical outcome measures (blood sugar and cholesterol levels, performance on the 10m cardiac shuttle test) as well as psychological measures (modified Hospital Anxiety and Depression Scale and SF-36 quality of life questionnaire). Data were analysed using within participant ANOVAs and preplanned t-tests. There were few significant changes across the course of the study. Non-significant trends occurred in the predicted direction for HADS anxiety and depression and for health-related qualify of life in terms of vitality, social functioning, role physical, bodily pain and general health. There was a significant reduction in total cholesterol across the course of the study, while non-significant changes occurred in the predicted direction for diastolic blood pressure (but not for systolic blood pressure or heart rate). As predicted, blood sugar levels decreased over time and improvements on the SWT approached significance (p=.07). Unexpectedly, HDL cholesterol significantly increased and TC/HDL cholesterol decreased across the 16 weeks. Changes in anxiety, depression, and health related quality of life across the two interventions (group/individual) were inconsistent and non-significant, although trends showed improvement in anxiety and depression after the social exercise intervention. Results are discussed in terms of small sample sizes and difficulties in conducting research with cardiac populations. Suggestions for future research are provided, including exploring patients’ perceptions, previous exercise history, support and preference for individual or group-based exercise programmes.Item The South Pacific Islands Resist Diabetes With Intense Training (SPIRIT) Study : impact of progressive resistance training and aerobic training on glycaemic control in Māori and Pacific Islands people with type 2 diabetes and grade III obesity : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Exercise and Sport Science, Institute of Food, Nutrition, and Human Health, College of Sciences, Massey University at Wellington, New Zealand(Massey University, 2010) Sukala, William ReedThe purpose of the South Pacific Islands Resist diabetes with Intense Training (SPIRIT) study was to evaluate and compare the effectiveness of two conventional training modalities for improving glycosylated haemoglobin (HbA1c) and related physiological and psychological outcomes in Polynesian adults diagnosed with type 2 diabetes and visceral obesity. Twenty-six adults of self-identified Māori or Pacific Islands descent (20 women, 6 men; 47 ± 8 years; 116.3 ± 27.5 kg; waist circumference 124.0 ± 17.8 cm) were randomised to progressive resistance training (PRT) or aerobic training (AER), 3x/week, for 16 weeks. Nine subjects per exercise group (n = 18) completed the study and were included in per protocol analyses. Within-group ANOVAs revealed that HbA1c remained elevated in PRT and AER after 16 weeks of training (10.7 ± 2.1 to 10.6 ± 2.4%, P > 0.05; 8.9 ± 1.9 to 8.8 ± 2.1%, P > 0.05, respectively). AER resulted in significant reductions in systolic (P = 0.006) and diastolic blood pressure (P = 0.02), an increase in skeletal muscle GLUT4 (P = 0.02), capillary density (P = 0.05), and power output (watts) (P < 0.001), while PRT resulted in a significant increase in upper (P = 0.001) and lower body strength (P < 0.001) and a reduction in hip circumference (P = 0.05). Eight (5 AER, 3 PRT) of 18 subjects completed ≥ 75% of available training sessions. Post-hoc analysis on these eight patients revealed a significant reduction in waist circumference (P < 0.001). Despite low attendance, many SF-36 QOL domains scores and the Physical Component Summary scores significantly improved in both groups (P ≤ 0.002). The findings of this doctoral research project suggest that improvement of metabolic outcomes may be delayed or overwhelmed by a combination of low attendance and class III morbid obesity (BMI ≥ 40 kg/m2). The improvements observed in QOL and muscle outcomes suggest that psychological and myocellular changes may precede changes in systemic metabolic outcomes. Additional research is required to investigate these hypotheses and overcome barriers to exercise adoption in Māori and Pacific Islands people with morbid obesity and type 2 diabetes.Item Whole body vibration training for multiple sclerosis patients : a thesis presented in partial fulfilment for the requirements for the degree of Master of Science in Exercise and Sport Science at Massey University, Palmerston North, New Zealand(Massey University, 2009) Mason, Rachael RuthIntroduction: The purpose of this study was firstly to investigate whether 8 weeks of whole body vibration (WBV) training was an acceptable form of exercise for patients with Multiple Sclerosis (MS) and secondly what effect it may have on measures of functional capacity. Methods: Fifteen participants with MS volunteered for WBV training three times a week on a commercialised Galileo Sport™ vibration machine with an oscillating platform. Training consisted of two four week blocks based on an increasing stimulus training programme (overload principle). The first fours weeks involving five sets of 1-min WBV with 1-min rest in between with increasing vibration frequency (15-25Hz, 2.6mm-4.1mm amplitude); the second four weeks training increased to eight sets of 1-min WBV (15-20Hz, 6.1mm amplitude). Functional performance measures (Timed up and Go, Standing Balance, Functional Reach and Timed walk) and quality of life questionnaire (SF-36) were conducted prior to training, at 4 weeks, 8 weeks and 2 weeks (10wk) following the completion of the training. Results: The 10m walk test showed significant improvements at the 2m, 8m and 10m measure between pre vs. 8wk (P<0.05) and pre vs.10wk (P<0.05). Timed up and Go demonstrated a significant time effect (P<0.05). Standing balance showed significant improvements at pre and 4 week (p<0.05) and pre and 10 week (p<0.05). Conclusions: This is the first study to investigate WBV as an exercise training modality for MS patients. It was shown that not only is WBV training safe, well tolerated by MS patients but it also improved standing balance and walking speed in MS patients.