This thesis is missing page 63 from all copies. -Digitization Centre / Manipulating carbohydrate (CHO) availability has been shown to alter acute exercise-induced changes in metabolic gene transcription and training-induced changes in oxidative capacity. The present study examined the effect of CHO availability on signalling pathways linked to mitochondrial biogenesis in response to high-intensity interval exercise (HIE). We hypothesized that reduced CHO availability would augment phosphorylation of AMP-activated protein kinase (AMPK), calcium/calmodulin-dependent kinase II (CaMKII), and p38 mitogen-activated protein kinase (p38) in response to HIE. Ten active men performed two experimental trials in random order, separated by 2:1 wk. During each trial, subjects performed two HIE sessions separated by 3 h (AM and PM sessions). Exercise sessions consisted of 5 x 4 min cycling bouts at a workload that elicited approximately 90% V02peak, with 2 min rest periods. Between sessions, subjects ingested -1.2 g CHO/kg b.w./h (HI-HI) or a taste-matched, non-energetic placebo (HI-LO). Muscle biopsies and blood samples were obtained before (Pre) and after (Post) the AM and PM HIE sessions. AMPK, CaMKII, and p38 MAPK phosphorylation increased from AM Pre to AM Post (p<0.01). During the PM exercise session, p38 phosphorylation increased in the HI-LO condition (-4.5-fold, p<0.001), whereas the HI-HI condition remained unchanged. PM HIE significantly increased CaMKII phosphorylation independent of condition, while no exercise or condition-mediated AMPK effects were observed. In summary, restricting CHO availability following an acute session of HIE augmented the exercise-induced increase in p38 phosphorylation during a subsequent HIE session. It remains to be determined whether chronic changes in p38 MAPK signalling are mechanistically linked to altered skeletal muscle remodelling observed after CHO-restricted exercise training. / Thesis / Master of Science (MS)

Background: Axial Spondyloarthritis (axSpA) is an autoimmune, chronic, rheumatic and inflammatory disease. In axSpA, the sacroiliac joint and the spine are affected, and common symptoms are stiffness and pain. For axSpA patients, systemic inflammation is a contributing factor to an increased risk of cardiovascular diseases (CVD). Calprotectin is a protein with multiple functions involved in the inflammatory response, and axSpA patients' calprotectin levels are elevated due to inflammation. Exercise is a non-pharmacological treatment, and for axSpA patients, it can reduce pain and increase mobility. The effects of High-intensity Interval Training (HIIT) have yet to be extensively researched in this patient group. Performing HIIT can increase maximal oxygen uptake (VO2max), reducing the risk of CVD. HIIT may also reduce inflammation, an essential factor in reducing the risk of CVD. Aim: The aim is to investigate how HIIT can affect calprotectin serum levels in axSpA patients and how calprotectin serum levels differ between healthy controls and axSpA patients. Method: Serum was collected before and after a HIIT bout from a cross-sectional pilot study, including axSpA patients (n=10) and healthy age- and sex-matched controls (n=11) and at baseline and after three months from a randomised control trial (RCT), which consisted of axSpA patients. The patients in the RCT were split into two groups: a control group (n=14) performing regular exercise and an intervention group (n=15) performing three HIIT sessions per week. Calprotectin in patients and healthy controls serum was analysed with a sandwich ELISA. Results: The comparison of serum calprotectin before and after a HIIT bout decreases in healthy controls (p=0.013) and indicates an increase of calprotectin in axSpA patients (p=0.059). After three months, the mean value of serum calprotectin in axSpA patients indicates a decrease in both the control and HIIT intervention groups. Conclusion: Our results suggest a trend towards regular HIIT, which can decrease serum calprotectin levels after three months. Therefore, HIIT could be considered a non-pharmacological treatment for axSpA patients. More studies with a larger axSpA population are necessary to investigate whether HIIT impacts serum calprotectin. / Bakgrund: Axial spondylartrit (axSpA) är en autoimmun, kronisk, reumatisk och inflammatorisk sjukdom. I axSpA påverkas sacroiliacaleden och ryggraden och vanliga symtom är stelhet och smärta. Patienter med axSpA har systemisk inflammation som är en bidragande faktor till ökad risk för hjärt-kärlsjukdomar (CVD). Kalprotektin är ett protein med flera funktioner som är involverat i den inflammatoriska responsen och hos patienter med axSpA är nivåerna av kalprotektin förhöjda på grund av inflammationen. Träning är en icke-farmakologisk behandling som kan minska smärta och öka rörlighet för axSpA patienter. Effekterna av högintensiv intervallträning (HIIT) har inte studerats i stor utsträckning i denna patientgrupp. Genom att utföra HIIT kan den maximala syreupptagningen (VO2max) förbättras, vilket kan minska risken för CVD. HIIT kan bidra till minskad inflammation, vilket kan minska risken för CVD. Syfte: Syftet är att undersöka hur HIIT kan påverka nivåerna av kalprotektin i serum hos patienter med axSpA och hur dessa nivåer skiljer sig mellan friska kontroller och patienter med axSpA. Metod: Serum har samlats in innan och efter ett HIIT pass från en tvärsnittsstudie och vid baseline och efter tre månader från en randomiserad kontrollstudie (RCT). Tvärsnittsstudien bestod av patienter med axSpA (n=10) samt friska ålders- och könsmatchade kontroller (n=11). RCTn bestod av patienter med axSpA som delades in i två grupper: en kontrollgrupp (n=14) som utförde regelbunden träning och en interventionsgrupp (n=15) som utförde tre HIIT-pass per vecka. Patienternas och de friska kontrollernas serum kalprotektin analyserades med en sandwich-ELISA. Resultat: Jämförandet av serum kalprotektin innan och efter ett HIIT pass hos friska kontroller visar en minskning av kalprotektin (p=0,013) och hos axSpA patienterna finns det en trend till en ökning av kalprotektin (p=0,059) efter HIIT-passet. Medelvärdet av serum kalprotektin hos axSpA patienter efter tre månader visar en tendens till en minskning i både kontroll- och HIIT-interventionsgruppen. Konklusion: Våra resultat indikerar att regelbunden HIIT efter tre månader kan minska nivåerna av serum kalprotektin. HIIT kan därför övervägas att vara en icke-farmakologisk behandling för axSpA patienter. Fler studier med en större axSpA population är nödvändigt för att vidare studera om HIIT påverkar serum kalprotektin.

High-intensity interval training (HIIT) consists of short intervals of exercise at high intensity intermitted by intervals of lower intensity and is associated with improvement of body composition and metabolic health in adults. Studies in overweight adolescents are scarce. We conducted a randomized controlled trial in overweight adolescents to compare acceptance and attendance of HIIT with or without weekly motivational encouragement through text messages and access to a study website. HIIT was offered for six months (including summer vacation) twice a week (60 min/session). Participation rates were continuously assessed and acceptance was measured. Clinical parameters were assessed at baseline and after six months. Twenty-eight adolescents participated in this study (age 15.5 +/- 1.4; 54% female). The standard deviation score for body mass index over all participants was 2.33 at baseline and decreased by 0.026 (95% CI - 0.048 to 0.10) units, p = 0.49. Waist to height ratio was 0.596 at baseline and decreased by 0.013 (95% CI 0.0025 to 0.024), p = 0.023. Participation within the first two months ranged from 65% to 75%, but fell to 15% within the last three months. Attendance in the intervention group was 14% (95% CI - 8 to 37), p = 0.18, higher than the control group. Overall program content was rated as \"good\" by participants, although high drop-out rates were observed. Summer months constitute a serious problem regarding attendance. The use of media support has to be assessed further in appropriately powered trials.

Training studies involving competitive runners and road cyclists have shown substantial gains in sprint and endurance performance when sessions of high-intensity interval training were added to their usual training in the competitive phase of a season. Further research has shown large performance benefits in sprint and endurance power (7 - 9%) when cyclists combined explosive single-leg jumps with cycling-specific high-intensity interval training during a competitive season. The aim of the present study was to assess the contribution of the jumps to the gains in performance in competitive cyclists in a randomized control trial.The training protocol for the control group was based on previous experimental work in which the control group (n=8) completed cycle specific interval training followed by a series of explosive single-leg jumps. The experimental group (n=7) carried out the same cycle specific interval training but did not participate in the explosive single-leg jumps. While the current study did not use a true control group, the investigation was carried out in the knowledge that a combination of high intensity interval cycling and explosive single-leg jumps causes changes positive changes in performance. Participants took part in 10 x 30-min sessions consisting four sets of high intensity intermittent cycling (4 x 30-s maximum efforts at 50 - 60 min-1 alternating with 30-s recovery). Between each set of 4 x 30 s sprints the control (ballistic) group carried out one set of explosive single-leg jumps (20 for each leg), while the experimental (continuous) group cycled for 20 s at 50 - 60 min-1.Before and after the training period all cyclists completed an incremental peak power test for assessment of VO2max, lactate threshold, exercise economy and peak power, a 30 s Wingate sprint test and a 20 km time-trial. Relative to the control group the percent mean changes (±90% confidence limits) in the experimental group were: power at 4-mM lactate, -4.2 (±6.3); VO2max, -3.1 (±3.7); mean time-trial power, -0.7 (± 4.7); peak incremental power, -1.7; (±5.0); power at 80% max heart rate, -2.8; (±5.6); Wingate peak power, -4.2; (±7.8). We conclude that high-intensity training may improve performance but the combination of high-intensity training and explosive resistance training in the competitive phase is likely to produce greater gains in trained cyclists than high intensity cycling alone.

Training studies involving competitive runners and road cyclists have shown substantial gains in sprint and endurance performance when sessions of high-intensity interval training were added to their usual training in the competitive phase of a season. Further research has shown large performance benefits in sprint and endurance power (7 - 9%) when cyclists combined explosive single-leg jumps with cycling-specific high-intensity interval training during a competitive season. The aim of the present study was to assess the contribution of the jumps to the gains in performance in competitive cyclists in a randomized control trial.The training protocol for the control group was based on previous experimental work in which the control group (n=8) completed cycle specific interval training followed by a series of explosive single-leg jumps. The experimental group (n=7) carried out the same cycle specific interval training but did not participate in the explosive single-leg jumps. While the current study did not use a true control group, the investigation was carried out in the knowledge that a combination of high intensity interval cycling and explosive single-leg jumps causes changes positive changes in performance. Participants took part in 10 x 30-min sessions consisting four sets of high intensity intermittent cycling (4 x 30-s maximum efforts at 50 - 60 min-1 alternating with 30-s recovery). Between each set of 4 x 30 s sprints the control (ballistic) group carried out one set of explosive single-leg jumps (20 for each leg), while the experimental (continuous) group cycled for 20 s at 50 - 60 min-1.Before and after the training period all cyclists completed an incremental peak power test for assessment of VO2max, lactate threshold, exercise economy and peak power, a 30 s Wingate sprint test and a 20 km time-trial. Relative to the control group the percent mean changes (±90% confidence limits) in the experimental group were: power at 4-mM lactate, -4.2 (±6.3); VO2max, -3.1 (±3.7); mean time-trial power, -0.7 (± 4.7); peak incremental power, -1.7; (±5.0); power at 80% max heart rate, -2.8; (±5.6); Wingate peak power, -4.2; (±7.8). We conclude that high-intensity training may improve performance but the combination of high-intensity training and explosive resistance training in the competitive phase is likely to produce greater gains in trained cyclists than high intensity cycling alone.

abstract: Heart failure is a major worldwide health concern and is the leading cause of hospitalization among elderly Americans. Approximately 50% of those diagnosed with heart failure have heart failure with preserved ejection fraction (HFPEF). HFPEF presents a therapeutic dilemma because pharmacological strategies that are effective for the treatment of heart failure and reduced ejection fraction have failed to show benefit in HFPEF. Long term moderate intensity exercise programs have been shown to improve diastolic function in patients HFPEF. High intensity interval training (HIIT) has been shown to improve diastolic function in patients with heart failure and reduced ejection fraction. However, the effects of high intensity interval training in patients with HFPEF are unknown. Fourteen patients with HFPEF were randomized to either: (1) a novel program of high-intensity aerobic interval training (n = 8), or (2) a commonly prescribed program of moderate-intensity (MOD) aerobic exercise training (n = 6). Before and after four weeks of exercise training, patients underwent a treadmill graded exercise test for the determination of peak oxygen uptake (VO2peak), a brachial artery reactivity test for assessment of endothelium-dependent flow-mediated dilation (BAFMD), aortic pulse wave velocity assessment as an index of vascular stiffness and two-dimensional echocardiography for assessment of left ventricular diastolic and systolic function. I hypothesized that (1) high-intensity aerobic interval training would result in superior improvements in FMD, aortic pulse wave velocity, VO2peak, diastolic function and, (2) changes in these parameters would be correlated with changes in VO2peak. The principal findings of the study were that a one month long high intensity interval training program resulted in significant improvements in diastolic function as measured by two-dimensional echocardiography [pre diastolic dysfunction (DD) grade - 2.13 + 0.4 vs. post DD grade - 1.25 + 0.7, p = 0.03]. The left atrial volume index was reduced in the HIIT group compared to MOD ( - 4.4 + 6.2 ml/m2 vs. 5.8 + 10.7 ml/m2, p = 0.02). Early mitral flow (E) improved in the HIIT group (pre - 0.93 + 0.2 m/s vs. post - 0.78 + 0.3 m/s, p = 0.03). A significant inverse correlation was observed between change in BAFMD and change in diastolic dysfunction grade (r = - 0.585, p = 0.028) when all the data were pooled. HIIT appears to be a time-efficient and safe strategy for improving diastolic function in patients with heart failure and preserved ejection fraction. These data may have implications for cardiovascular risk reduction in this population. / Dissertation/Thesis / Ph.D. Exercise and Wellness 2012

abstract: The winter holiday period has been highlighted as a major risk period for weight gain due to excess caloric intake in the form of fat and sugar. Furthermore, diets high in fat and sugar have been implicated in the pathogenesis of diabetes and cardiovascular disease. Exercise aids in the prevention of weight/fat gain, and prevents deleterious changes in cardiometabolic function. The objective of this study was to examine the effects of a fat-sugar supplemented diet, with and without two different exercise training protocols, on body composition, glycemic control and other markers of cardiovascular disease in an at-risk population of overweight and obese males. Twenty-seven, healthy overweight/obese (BMI >25 kg/m2) males were fed 2 donuts per day, 6 days/week, for four weeks, while maintaining their current diet. In addition, all subjects were randomized to one of the following conditions: sedentary control, 1,000 kcal/week moderate-intensity continuous training (MICT) (50% of peak oxygen consumption), or 1,000 kcal/week high-intensity interval training (HIIT) (90-95% of peak heart rate). Supervised exercise training was performed 4 days/week on a cycle ergometer. Changes in body weight and composition, endothelial function, arterial stiffness, glycemic control, blood lipids and cardiorespiratory fitness (CRF) were assessed before and after the intervention. Body weight, lean mass and visceral fat increased significantly in HIIT (p<0.05) and were unchanged in MICT. There was a trend for a significant increase in body weight (p=0.07) and lean mass (p=0.11) in control. Glycemic control during the 2-h OGTT improved significantly in MICT and control, with no change in HIIT. Hepatic insulin resistance index (IRI) and 30-min insulin during the OGTT improved significantly after MICT and worsened following control (p=0.03), while HIIT was unchanged. CRF increased significantly in both HIIT and MICT, with no change in control (p<0.001). There were no significant changes in other markers of cardiovascular disease. The addition of a fat-sugar supplement (~14,500 kcal) over a 4-week period was not sufficient to induce deleterious changes in body composition and cardiometabolic health in overweight/obese young males. Exercise training did not afford overweight/obese males additional health benefits, with the exception of improvements in fitness and hepatic IRI. / Dissertation/Thesis / Doctoral Dissertation Physical Activity, Nutrition and Wellness 2016

No description available.

The aim of this master thesis is to evaluate the influence of a six-week HIIT (High intensity interval training) on body composition and both aerobic and anaerobic performance. A group of 9 men aged 28-51 years was gathered and who followed an exact six-week training programme according to the chosen hypothesis. The results of our study show that the chosen six-week programme led to statistically significant (p < 0,05) changes in body weight (kg), BMI (kg/m2 ), in FEV (l), and ANC/kg (J/kg). Changes in the other parameters were statistically not significant. Taking into account the size of group (n=9) we conclude that mainly effects on the individual level were attained.

Background: Repeated sprint training in hypoxia has shown to be superior to training in normoxia. However, both natural and simulated altitude training are strategies that are not always accessible and expensive due to traveling or the need for advanced equipment. A possible way of simulating hypoxic conditions is to administer carbon monoxide (CO) prior to training as it has been shown to reduce the oxygen transport and delivery to the muscle similar to systemic hypoxia. It is therefore hypothesized that inhaling a small bolus of CO prior to repeated-sprint exercise will potentiate the acute physiological responses during the training, thus induce performance improvements associated with repeated sprint ability compared to placebo control. Methods: 23 endurance-trained individuals (18 men and 5 women), age 33.2 ± 6.9 years, body mass 78.3 ± 11.0 kg, height 180.7 ± 7.3 cm, performed a 3-week supervised repeated sprint exercise protocol on electromagnetically braked cycle ergometers. A repeated sprint ability test was conducted pre-and post-training intervention. Participants were randomly assigned to either inhaling CO (INCO group) or inhaling a sham gas (NOCO group). Analysis of covariance (ANCOVA) was conducted to determine statistical significance by controlling for pre-test values. Results: Periodic inhalation of CO prior to repeated sprint exercise led a medium, significant difference in mean power decrement (INCO -2.63%, NOCO 8%; p &lt;0.05, ηp2 = 0.19) and fatigue index (INCO 0.28%, NOCO 8.2%; p &lt;0.05, ηp2 = 0.24) compared to sham gas, despite that both groups increased in number of sprints (INCO 16.58%, NOCO 27.60%; p &lt;0.05; ηp2 = 0.71) with no difference between groups. Conclusion: Our findings in this study showed a positive effect on an improved ability to sustain power output during repeated sprints when periodic inhalation of CO is administered. Therefore, it is suggested that periodic inhalation of CO prior to repeated sprint exercise might be a nuanced way to induce favorable physiological adaptations, thus improving performance associated with repeated sprint ability.