Matching Items (3)
Description
High Intensity Interval Training (HIIT) is a phrase quickly becoming popularized through current research due to the physical and physiological success this method of training has proven to yield in both untrained and trained individuals. There is no set definition used to describe HIIT, but it typically refers to repeated bouts of fairly brief intermittent exercise. A great deal of research outlines the benefits associated with utilizing HIIT in untrained and recreationally trained individuals. However, research on the effect HIIT has or could possibly have on the well-trained endurance athlete is limited, specifically in the sport of rowing. The purpose of this study was to analyze the effect of HIIT on VO2 peak and performance in trained rowers when compared to traditional, endurance training. It was hypothesized that HIIT would be just as effective at improving VO2 peak and performance as the endurance training protocol in well-trained rowers. A total of 20 high school female rowers participated in the study (mean ± SD; age = 16 ± 1). Baseline testing was comprised of a 2000m time-trial test on the Concept IIc Rowing Ergometer and a maximal exercise test, which was also completed on the Concept IIc Ergometer, in order to determine VO2 peak. Subjects were randomly assigned to a HIIT or endurance group for four weeks of intervention. Three days/week the HIIT group completed a 6 by 30second repeated Wingate protocol on the Concept II Ergometer at or above 100% VO2 peak, in which each 30s maximal effort was immediately followed by an active recovery of four-minutes. The endurance group completed 30 minutes of sub-maximal rowing at 65% of VO2 peak three days/week. After four weeks of intervention, post-testing took place, which was identical to baseline testing. Results from this study suggest HIIT was just as effective as endurance training at improving 2k time (mean ± SD; HIIT: 498.7 ± 23.1; Endurance: 497.5 ± 17.6). There were no significant within or between group differences in VO2 peak post-intervention (mean ± SD; HIIT: 44.8 ± 4.0; Endurance: 45.8 ± 5.6). The current study suggests four-weeks of HIIT training can yield similar adaptations in performance when compared to endurance training.
ContributorsCarr, Natasha (Author) / Chisum, Jack (Thesis advisor) / Campbell, Kathryn (Committee member) / Woodruff, Larry (Committee member) / Arizona State University (Publisher)
Created2011
Description
Cardiovascular disease and diabetes are major health burdens. Diabetes is a primary risk factor of cardiovascular disease, and there is a strong link between obesity and risk of developing diabetes. With the prevalence of prediabetes highest among overweight/obese individuals, investigation into preventative strategies are needed. Aerobic exercise is a potent stimulus for both insulin and non-insulin dependent glucose uptake into the skeletal muscle. A single exercise session can improve insulin sensitivity within hours after exercise. The effects of intensity, type, and volume of exercise on glucose homeostasis have been studied extensively; however, controlling for muscle contraction frequency with a constant exercise intensity and workload has not been examined. The purpose of this study was to compare muscle contraction frequency during aerobic exercise by altering cycling cadence on insulin sensitivity and vascular health. Eleven obese males (age=28yr, BMI=35kg/m2) completed three conditions in random order: 1) control-no exercise; 2) 45-min cycling at 45 revolutions per minute (45RPM) at 65-75%VO2max; 3) 45-min cycling at 90RPM at 65-75%VO2max. Glucose control and insulin sensitivity were assessed with oral glucose tolerance tests (OGTT) 4 hours post-exercise. Vascular health was assessed via flow-mediated dilation (FMD) pre-exercise, 1-hr and 2-hr post exercise and ambulatory blood pressure was assessed pre-exercise, and continually every 15 min post-exercise. Linear mixed models were used to compare the mean differences in outcome variables. There were no significant differences found between control and both exercise conditions for all OGTT outcomes and no differences were found between control and exercise in FMD (all, p>0.05). Significant effects for exercise were found for both brachial and central blood pressure measures. Brachial systolic blood pressures were lower at 2- and 4-hr post-exercise by approximately -10 and -8mmHg, respectively (p<0.001 and p=0.004) versus control. Central systolic blood pressures were lower at 2-, 3-, and 4-hr post-exercise by approximately -8, -9 and -6mmHg, respectively (p<0.001, p=0.021 and p=0.004) versus control. In conclusion, aerobic exercise, regardless of muscle contraction frequency, were unable to effect glucose control and insulin sensitivity. Similarly, there was no effect on vascular function. However, there was a significant effect of aerobic exercise on reducing post-exercise blood pressure.
ContributorsJarrett, Catherine Lee (Author) / Gaesser, Glenn A (Thesis advisor) / Angadi, Siddhartha S (Committee member) / Dickinson, Jared M (Committee member) / Whisner, Corrie M (Committee member) / Todd, Michael W (Committee member) / Arizona State University (Publisher)
Created2017
Description
Background: Stroke is a leading cause of long-term disability in the United States (US). Assisted Cycling Therapy (ACT) incorporates the use of an electric motor to enhance the rotations per minute (rpm). ACT of about 80 rpm, has been associated with improvements in motor, cognitive, and clinical function. The acute effects of ACT on motor and cognitive function of persons with stroke induced deficits have not been investigated.
Purpose: To compare the acute effects of ACT, voluntary cycling (VC), and no cycling (NC) on upper and lower extremity motor function and executive function in adults with chronic stroke (age: 60 ± 16 years; months since stroke: 96 ± 85).
Methods: Twenty-two participants (gender: female = 6, male = 16; types: ischemic = 12, hemorrhagic = 10; sides: left lesion = 15, right lesion = 7) completed one session of ACT, one session of VC and one session of NC on separate days using a 3 x 3 crossover design.
Results: ACT lead to greater improvements in lower and upper extremity function on the paretic and non-paretic side than VC or NC (all p < 0.05), except in the non-paretic lower extremity where ACT and VC produced similar improvement (both p < 0.05). ACT and VC, but not NC, were associated with improvements in inhibition (p < 0.05). A positive relationship between cadence and motor function (P < 0.05) was found. Ratings of perceived exertion shared an inverted-U shaped relationship with measures of processing speed (p < 0.05) and a negative linear relationship with measures of executive function (p < 0.05).
Conclusion: ACT appears to benefit paretic and non-paretic motor function globally whereas the benefits of VC are more task specific. Faster cycling cadence was associated with greater improvements in global motor function. ACT and VC seem to carry similar acute benefits in inhibition.
Purpose: To compare the acute effects of ACT, voluntary cycling (VC), and no cycling (NC) on upper and lower extremity motor function and executive function in adults with chronic stroke (age: 60 ± 16 years; months since stroke: 96 ± 85).
Methods: Twenty-two participants (gender: female = 6, male = 16; types: ischemic = 12, hemorrhagic = 10; sides: left lesion = 15, right lesion = 7) completed one session of ACT, one session of VC and one session of NC on separate days using a 3 x 3 crossover design.
Results: ACT lead to greater improvements in lower and upper extremity function on the paretic and non-paretic side than VC or NC (all p < 0.05), except in the non-paretic lower extremity where ACT and VC produced similar improvement (both p < 0.05). ACT and VC, but not NC, were associated with improvements in inhibition (p < 0.05). A positive relationship between cadence and motor function (P < 0.05) was found. Ratings of perceived exertion shared an inverted-U shaped relationship with measures of processing speed (p < 0.05) and a negative linear relationship with measures of executive function (p < 0.05).
Conclusion: ACT appears to benefit paretic and non-paretic motor function globally whereas the benefits of VC are more task specific. Faster cycling cadence was associated with greater improvements in global motor function. ACT and VC seem to carry similar acute benefits in inhibition.
ContributorsHolzapfel, Simon D (Author) / Ringenbach, Shannon D (Thesis advisor) / Bosch, Pamela R (Committee member) / Lee, Chong D (Committee member) / Der Ananian, Cheryl A (Committee member) / Hooker, Steven P (Committee member) / Arizona State University (Publisher)
Created2017