Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- Action Potential (1)
- Acute exercise (1)
- Adenylyl cyclase (1)
- Age (1)
- Aging (1)
-
- Cardiovascular Disease (1)
- Cardiovascular system (1)
- Concurrent stressors (1)
- Decomposition based quantitative electromyography (1)
- Diet manipulation (1)
- Dorsiflexors (1)
- Electromechanical Delay (1)
- Exercise performance (1)
- Exercise physiology (1)
- Firing rates (1)
- First dorsal interosseous (1)
- Handgrip exercise (1)
- Heart rate (1)
- Heart rate variability (1)
- Insula cortex (1)
- Interval training (1)
- Lengthening contractions (1)
- MANOVA (1)
- Motor unit recruitment (1)
- Muscle Sympathetic Nerve Activity (1)
- O2 uptake kinetics; near-infrared spectroscopy; NIRS; metabolism; intramuscular metabolites (1)
- Oxygen uptake (1)
- Self-regulation (1)
- Smoking (1)
- Somatosensory stimulation (1)
Articles 1 - 9 of 9
Full-Text Articles in Life Sciences
A Six Week Modified Sprint Interval Training Program Incorporating Extended Exercise Bouts Does Not Increase Maximal Cardiac Output, Alan R. Smith
A Six Week Modified Sprint Interval Training Program Incorporating Extended Exercise Bouts Does Not Increase Maximal Cardiac Output, Alan R. Smith
Electronic Thesis and Dissertation Repository
Sprint interval training (SIT) improves maximal oxygen uptake (V̇O2max) and exercise performance but not maximal cardiac output (Q̇max). The brevity of typical SIT bouts (30-seconds) might hinder improvements in Q̇max. The purpose of this study was to determine whether extended duration SIT (up to 45 second bouts) improves Q̇max. Pre-/Post-SIT (or control) V̇O2max, Q̇max, maximum stroke volume (SVmax), maximum heart rate, arterial-mixed venous oxygen difference, and 5-minute run distance were measured. SIT progressed from 4x30s to 7x45s “all-out” efforts (4 min recovery) over 6 wk (3x/wk) …
A Quantitative Emg Assessment Of Motor Unit Recruitment In Patients With Ulnar Neuropathy, Kayla N. Ryan
A Quantitative Emg Assessment Of Motor Unit Recruitment In Patients With Ulnar Neuropathy, Kayla N. Ryan
Electronic Thesis and Dissertation Repository
The aim of the current study was to assess the test – retest reliability of motor unit firing rates with the use of decomposition based quantitative electromyography, and to quantify motor unit firing rates in the first dorsal interosseous of patients with ulnar neuropathy. 8 healthy subjects (mean age 35 ± 10 years) and 8 patients (mean age 48 ± 10 years) with ulnar neuropathy participated in the study. Following the acquisition of a maximum M wave, needle and surface detected EMGs were collected simultaneously during 30-second contractions performed at threshold (1-2% maximum voluntary contraction (MVC)) and 10% MVC- RMS …
Electromechanical Delay Of The Dorsiflexors In Young And Old Women, In H. Choi
Electromechanical Delay Of The Dorsiflexors In Young And Old Women, In H. Choi
Electronic Thesis and Dissertation Repository
PURPOSE: The aim of the current study was to examine the effect on electromechanical delay (EMD) in the dorsiflexors of young and old women during maximal isometric voluntary and electrically evoked contractions, and after a bout of lengthening contractions. METHODS: Nine young (25.1±1.3 years) and nine old (68.3±6.1 years) women performed baseline isometric contractions with evoked twitches followed by a series of dynamic lengthening contractions using a Biodex multi-joint dynamometer. Maximal isometric voluntary and evoked contractions were measured to assess EMD. Time points were recorded at baseline, mid-point of the intervention, post-task termination, and during recovery at 0.5, 2, 10, …
The Effect Of Low And High Carbohydrate Diets On Pulmonary Oxygen Uptake And Muscle Deoxygenation Kinetics During Exercise Transitions Into The Heavy-Intensity Domain, John Leckie
Electronic Thesis and Dissertation Repository
The purpose of this study was to determine the effects of a high carbohydrate (HCHO) and low carbohydrate (LCHO) diet on the adjustment of pulmonary oxygen (O2) uptake ( ) and muscle deoxygenation ([HHb]) during transitions to heavy intensity exercise. Young, healthy, male subjects aged (24+/-3) underwent a 4 day LCHO followed immediately by a 4 day HCHO diet, with each diet preceded by a glycogen depletion protocol. This protocol was designed to alter PDH activity. Subjects completed 3 step transitions to a work rate corresponding to 35% of the difference between their lactate threshold and peak for …
Role Of Adenylyl Cyclase S674 In Central And Forearm Vasomotor Control, James Corkal
Role Of Adenylyl Cyclase S674 In Central And Forearm Vasomotor Control, James Corkal
Electronic Thesis and Dissertation Repository
This study examined the cardiac and vasomotor responses to submaximal handgrip exercise and beta-adrenergic control in carriers (n = 6) and non-carriers (n = 4) of a genetic variant of adenylyl cyclase 6 (AC S674). Rhythmic handgrip contractions (1 minute bout; 2 second contraction-relaxation period) were performed at three different intensities (20, 40, and 60% of maximal voluntary contraction force) to test the vasodilatory response to exercise. Additionally, two 5 minute infusions of isoproterenol (0.01 and 0.02 µg·kg-1·min-1 diluted in 5% dextrose) and one 10 minute infusion of propranolol (0.1 mg·kg-1 diluted in 0.9% saline) were …
Adjustment Of Pulmonary O2 Uptake, Muscle Deoxygenation And Metabolism During Moderate-Intensity Exercise Transitions Initiated From Low And Elevated Baseline Metabolic Rates, Joshua P. Nederveen
Adjustment Of Pulmonary O2 Uptake, Muscle Deoxygenation And Metabolism During Moderate-Intensity Exercise Transitions Initiated From Low And Elevated Baseline Metabolic Rates, Joshua P. Nederveen
Electronic Thesis and Dissertation Repository
When instantaneous step-wise transitions within the moderate intensity domain are initiated from elevated metabolic rates, the rate of pulmonary oxygen uptake (V̇O2p) adjustment is slowed, and the V̇O2p gain (ΔV̇O2p /ΔWR) is greater. This study sought to determine the relationship between V̇O2p kinetics and metabolic activity and energy status during step transitions from low and elevated metabolic rates within the moderate intensity domain. Ten young men completed six double-step constant load cycling bouts, consisting of step-wise transitions from 20 W to 45% θL and 45% θL [lower step (LS)] to 90% θL …
The Effect Of Exercise On Cravings And Ad Libitum Smoking Following Concurrent Stressors, Angela J. Fong
The Effect Of Exercise On Cravings And Ad Libitum Smoking Following Concurrent Stressors, Angela J. Fong
Electronic Thesis and Dissertation Repository
Quitting smoking itself is a stressor; it is likely that other stressors occur concurrently and deplete self-regulatory resources. Failure to cope leads to smoking relapse. Exercise has been shown to attenuate cravings and withdrawal symptoms in previous research and has yet to be examined following concurrent stressors. This study examined the effect of an acute bout of moderate intensity exercise on psychological withdrawal symptoms (PWS), cravings and ad lib smoking after concurrent stressors (i.e., temporary abstinence and depletion). Twenty-five smokers were randomized into exercise or passive conditions. Results showed PWS were significantly exacerbated after temporary abstinence and again after depletion …
Somatosensory Stimulation Modulates Heart Rate Variability Changes Induced By Isometric Handgrip Exercise, Jacquie Baker
Somatosensory Stimulation Modulates Heart Rate Variability Changes Induced By Isometric Handgrip Exercise, Jacquie Baker
Electronic Thesis and Dissertation Repository
Functional imaging reveals overlapping forebrain and basal ganglia regions associated with heart rate (HR) and heart rate variability (HRV) regulation. Somatosensory stimulation (STIM) and isometric handgrip (HG) were used to test the hypotheses that a) STIM would modulate HG-induced changes to HR and HRV, and b) HG+STIM would produce different cortical activation relative to HG alone (n=12). During STIM, high-frequency (HF)-HRV increased (p<0.05), whereas HR did not change. During HG, HF-HRV decreased (p<0.01) while HR increased (p<0.001). HG+STIM reversed the HG-induced change in HF-HRV (p<0.01). However, the HR response to HG remained unaffected. HG increased insular activation, while ventral medial prefrontal cortex (vMPFC) activity decreased. HG+STIM produced similar vMPFC deactivation. However, insular activation was no longer evident. These data indicate that somatosensory inputs through STIM can modulate HG-induced changes to HF-HRV. Different insular activations during HG versus HG+STIM suggest afferent signals to the insula may inhibit descending motor signals affecting HF-HRV.
Assessing Multi-Unit Muscle Sympathetic Nerve Activity Across Groups: A Multivariate Approach To A Multivariate Concept, Danielle N. Brewer
Assessing Multi-Unit Muscle Sympathetic Nerve Activity Across Groups: A Multivariate Approach To A Multivariate Concept, Danielle N. Brewer
Electronic Thesis and Dissertation Repository
Baseline muscle sympathetic nerve activity (MSNA) comparisons of age (young & old, n=40) and cardiovascular disease (CVD) state (young: Y, old: O, metabolic syndrome: MET, coronary artery disease: CAD, chronic heart failure: CHF, n= 36) groups were made to assess which MSNA variable(s) best describe group differences using a MANOVA-based approach across 10 variables. The hypothesis that action potential (AP) variables would better discriminate between groups than integrated variables was not supported. Burst frequency and incidence together significantly differentiated between groups with variability attributed to spikes/min and spikes/100hb removed. Significant group differences were noted for these variables such that Y