Exercise Physiology Commons^™

Lactate's Role In Appetite Suppression, Seth Mccarthy

Theses and Dissertations (Comprehensive)

Once considered metabolic waste produced during exercise, lactate is now known to have diverse roles in biology. Muscle-derived lactate can travel through the bloodstream and be taken up by other tissues and i) oxidized, ii) converted to glucose via gluconeogenesis, or iii) bind to its receptor to trigger molecular signaling cascades. Lactate has been described as a “myokine” capable of inter-organ crosstalk and compelling evidence demonstrates lactate’s role as a signalling molecule in pathways related to the regulation of appetite. The purpose of this dissertation was to further elucidate lactate’s role in appetite regulation using series of studies aimed at …

Modulation Of Persistent Inward Currents With Changes In Posture And Cutaneous Sensory Input, Ryan William Weller

Theses and Dissertations (Comprehensive)

Spinal motor neuron (MN) persistent inward currents (PIC) increase and sustain the MN output. PIC is amplified by descending monoamines and reduced by afferent inhibition. There is strong coupling between plantar cutaneous sensory input and lower limb MNs. Given that monoaminergic drive is altered with postures and motor tasks, our purpose was to assess posture-dependent plantar cutaneous sensory modulation of tibialis anterior (TA) MNs. We hypothesize that: 1) a supine position will suppress PIC, 2) removing the load from the bottom of the heel will inflate PIC, and 3) cutaneous stimulation of the plantar aspect of the heel will reduce …

Role Of Training Mode On Individual And Group Responses To Sprint Interval Training, Lauren T. Digby, Seth F. Mccarthy, Claudia Jarosz, Derek P.D. Bornath, Jessica A.L. Tucker, Tom J. Hazell

Theses and Dissertations (Comprehensive)

Improvements in V̇O_2peak decrease the risk of heart disease and all-cause mortality, and is predictive of overall health. This study compared the group and individual responses of V̇O_2peak, as well as group responses of aerobic performance and anaerobic capacity following running and cycling sprint interval training (SIT) to determine the optimal modality. Twenty-three recreationally active young adults (males: n = 16, BMI = 27.5±4.9; females: n = 7, BMI = 23.6±3.0) completed 3 training sessions/week for 3 weeks (9 sessions). Pre- and post-testing measures included: aerobic capacity (V̇O_2peak), aerobic performance (time trial), and anaerobic capacity …

Examining The Effects Of Interleukin-6 On Appetite Regulatory Peptides In Lean And Obese Sedentary Males, Greg L. Mckie

Theses and Dissertations (Comprehensive)

Acute moderate-intensity exercise transiently suppresses appetite via fluctuations in the appetite-regulatory peptides acylated ghrelin (AG), peptide tyrosine-tyrosine_3-36 (PYY_3-36), and active glucagon-like peptide-1 (GLP-1). Importantly, these effects do not lead to compensatory changes in energy intake in normal weight or obese individuals, highlighting the potential for exercise to induce acute energy deficits. One potential mechanism for these effects is increased post-exercise plasma concentrations of interleukin (IL)-6, as IL-6 has demonstrated appetite-inhibitory effects in animal and cell culture models. Given obesity is characterized by a state of chronic low-grade inflammation and associated with upregulated IL-6, this study sought to …

The Effects Of Exercise Intensity On Acylated Ghrelin, Active Glucagon-Like Peptide-1, And Appetite: Examining The Potential Involvement Of Interleukin-6, Hashim Islam

Theses and Dissertations (Comprehensive)

Interleukin-6 (IL-6) stimulates the release of appetite-regulating hormones in animals and associates with decreased energy intake in humans. Thus, IL-6 may contribute to the intensity- dependent effects of exercise on appetite-related parameters. The purpose of this study was to examine the effects of exercise intensity on IL-6, appetite-regulating hormones, and appetite perceptions. Eight active young males completed four sessions: 1) Moderate-intensity continuous training (MICT; 30 min running, 65% VO2max); 2) High-intensity continuous training (HICT; 30 min running, 85% VO2max); 3) Sprint interval training (SIT; 4 x 30 sec “all-out” running bouts separated by 4 min recovery); 4) Control (CTRL; no …

Estimates Of Persistent Inward Current In Human Motor Neurons During Postural Sway, Ryan Foley, Jayne M. Kalmar Dr.

Theses and Dissertations (Comprehensive)

Persistent inward current (PIC) is a membrane property critical for increasing gain of motor neuron output. In humans, most estimates of PIC are made from plantarflexor or dorsiflexor motor units with the participant in a seated position with the knee flexed. This seated and static posture neglects the task-dependent nature of the monoaminergic drive that modulates PIC activation. Seated estimates may drastically underestimate the amount of PIC that occurs in human motor neurons during functional movement. The current study estimated PIC using the conventional paired motor unit technique which uses the difference between reference unit firing frequency at test unit …

The Effect Of Cadmium Exposure On Repeat Swimming Performance And Recovery In Rainbow Trout (Oncorhynchus Mykiss), Brown Trout (Salmo Trutta) And Lake Whitefish (Coregonus Clupeaformis), Jessie L. Cunningham

Theses and Dissertations (Comprehensive)

Swim performance provides a measure of the integrated metabolic costs of sub-lethal exposure to stressors, including Cd. While the impacts to sustained swimming performance in Cd exposed fish have already been characterised, effects to repeat swimming ability have not. This thesis identifies the effects of sub-lethal waterborne Cd exposure on ionoregulatory function, repeat swimming ability, anaerobic metabolism and stress response in rainbow trout (Oncorhynchus mykiss), brown trout (Salmo trutta) and lake whitefish (Coregonus clupeaformis).

Repeat swim trials included an initial swim to 85% of the U_crit of control fish and a recovery period …