{"id":{"repo_id":"montana-tech","oai_identifier":"oai:scholarworks.umt.edu:etd-2183"},"canonical_url":"https://search.dev.ndltd.org/etd/montana-tech/oai:scholarworks.umt.edu:etd-2183","repository":{"repo_id":"montana-tech","name":"Montana Technology","base_url":"https://scholarworks.umt.edu/do/oai/"},"display":{"title":"Variability of substrate utilization during exercise relative to VO2vt and VO2max","abstract":"Lieberg, Erika M., M.S., May 2007 Health and Human Performance Variability of substrate utilization during exercise relative to VO2vt and VO2max Chairperson: Steven E. Gaskill PURPOSE: The purpose of this study was to determine to the stability of ventilatory threshold (VT) as a set point for prescription of exercise intensity. METHODS: Fifty-eight healthy adults (males n = 28, females n = 30) performed VO2max and steady state testing. The VO2max test used a treadmill ramp protocol to determine VO2max and VO2vt. The results were used to determine workload exercise relative to VO2vt and VO2max (70% VO2vt ? 40% VO2max, 90% VO2vt ? 50% VO2max, 125% VO2vt ? 65% VO2max). During the steady state test, subjects walked for 4 minutes at each of the workloads associated with the six exercise intensities. These stages were sequentially completed in the order of increasing intensity. Ventilation (VE), respiratory gas-exchange ratio (RER), VO2, and VCO2 were measured continuously and heart rate and rate of perceived exertion (RPE) were collected each minute. RESULTS: The mean overall variance of RER at the %VO2vt intensities was significantly less than at the %VO2max intensities (%VO2vt = 0.030±0.025, %VO2max = 0.041±0.029, p<0.001). The mean RER variance was not different between genders relative to %VO2vt (p>0.05). For males and females, the variance in RER was significantly less when evaluated at 70% and 90% of VO2vt than at 40% and 50% of VO2max respectively (p<0.001). When the RER mean variance values were compared at the 125%VO2vt vs. 65%VO2max, RER variance values within subjects (males, females and overall) were not different (p>0.05). Similar patterns in RER variance were seen when compared by body mass index (BMI) or fitness. CONCLUSIONS: Using % VO2vt is a viable method to prescribe exercise intensity during research and/or training, with overall lower RER variance, especially when the intensity of exercise is below the ventilatory threshold.","abstract_html":"Lieberg, Erika M., M.S., May 2007 Health and Human Performance Variability of substrate utilization during exercise relative to VO2vt and VO2max Chairperson: Steven E. Gaskill PURPOSE: The purpose of this study was to determine to the stability of ventilatory threshold (VT) as a set point for prescription of exercise intensity. METHODS: Fifty-eight healthy adults (males n = 28, females n = 30) performed VO2max and steady state testing. The VO2max test used a treadmill ramp protocol to determine VO2max and VO2vt. The results were used to determine workload exercise relative to VO2vt and VO2max (70% VO2vt ? 40% VO2max, 90% VO2vt ? 50% VO2max, 125% VO2vt ? 65% VO2max). During the steady state test, subjects walked for 4 minutes at each of the workloads associated with the six exercise intensities. These stages were sequentially completed in the order of increasing intensity. Ventilation (VE), respiratory gas-exchange ratio (RER), VO2, and VCO2 were measured continuously and heart rate and rate of perceived exertion (RPE) were collected each minute. RESULTS: The mean overall variance of RER at the %VO2vt intensities was significantly less than at the %VO2max intensities (%VO2vt = 0.030±0.025, %VO2max = 0.041±0.029, p&lt;0.001). The mean RER variance was not different between genders relative to %VO2vt (p&gt;0.05). For males and females, the variance in RER was significantly less when evaluated at 70% and 90% of VO2vt than at 40% and 50% of VO2max respectively (p&lt;0.001). When the RER mean variance values were compared at the 125%VO2vt vs. 65%VO2max, RER variance values within subjects (males, females and overall) were not different (p&gt;0.05). Similar patterns in RER variance were seen when compared by body mass index (BMI) or fitness. CONCLUSIONS: Using % VO2vt is a viable method to prescribe exercise intensity during research and/or training, with overall lower RER variance, especially when the intensity of exercise is below the ventilatory threshold.","abstract_has_math":false,"creators":["Lieberg, Erika Marie"],"institution":"University of Montana","degree_name":"Master of Science (MS)","degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2007,"date_issued":"2007-01-01T08:00:00Z","date_published":"2007-01-01T08:00:00Z","updated_at":"2026-07-24T03:14:21Z","subjects":["maximal oxygen consumption","RER","training","ventilatory threshold"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://scholarworks.umt.edu/etd/1164","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Lieberg, Erika Marie"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:publisher","label":"Institution","values":["University of Montana"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science (MS)"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["maximal oxygen consumption","RER","training","ventilatory threshold"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://scholarworks.umt.edu/etd/1164"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Lieberg, Erika M., M.S., May 2007 Health and Human Performance Variability of substrate utilization during exercise relative to VO2vt and VO2max Chairperson: Steven E. Gaskill PURPOSE: The purpose of this study was to determine to the stability of ventilatory threshold (VT) as a set point for prescription of exercise intensity. METHODS: Fifty-eight healthy adults (males n = 28, females n = 30) performed VO2max and steady state testing. The VO2max test used a treadmill ramp protocol to determine VO2max and VO2vt. The results were used to determine workload exercise relative to VO2vt and VO2max (70% VO2vt ? 40% VO2max, 90% VO2vt ? 50% VO2max, 125% VO2vt ? 65% VO2max). During the steady state test, subjects walked for 4 minutes at each of the workloads associated with the six exercise intensities. These stages were sequentially completed in the order of increasing intensity. Ventilation (VE), respiratory gas-exchange ratio (RER), VO2, and VCO2 were measured continuously and heart rate and rate of perceived exertion (RPE) were collected each minute. RESULTS: The mean overall variance of RER at the %VO2vt intensities was significantly less than at the %VO2max intensities (%VO2vt = 0.030±0.025, %VO2max = 0.041±0.029, p<0.001). The mean RER variance was not different between genders relative to %VO2vt (p>0.05). For males and females, the variance in RER was significantly less when evaluated at 70% and 90% of VO2vt than at 40% and 50% of VO2max respectively (p<0.001). When the RER mean variance values were compared at the 125%VO2vt vs. 65%VO2max, RER variance values within subjects (males, females and overall) were not different (p>0.05). Similar patterns in RER variance were seen when compared by body mass index (BMI) or fitness. CONCLUSIONS: Using % VO2vt is a viable method to prescribe exercise intensity during research and/or training, with overall lower RER variance, especially when the intensity of exercise is below the ventilatory threshold."]},{"key":"dc:title","label":"Title","values":["Variability of substrate utilization during exercise relative to VO2vt and VO2max"]}]}],"canonical_facts":{"dc:creator":["Lieberg, Erika Marie"],"dc:description.abstract":["Lieberg, Erika M., M.S., May 2007 Health and Human Performance Variability of substrate utilization during exercise relative to VO2vt and VO2max Chairperson: Steven E. Gaskill PURPOSE: The purpose of this study was to determine to the stability of ventilatory threshold (VT) as a set point for prescription of exercise intensity. METHODS: Fifty-eight healthy adults (males n = 28, females n = 30) performed VO2max and steady state testing. The VO2max test used a treadmill ramp protocol to determine VO2max and VO2vt. The results were used to determine workload exercise relative to VO2vt and VO2max (70% VO2vt ? 40% VO2max, 90% VO2vt ? 50% VO2max, 125% VO2vt ? 65% VO2max). During the steady state test, subjects walked for 4 minutes at each of the workloads associated with the six exercise intensities. These stages were sequentially completed in the order of increasing intensity. Ventilation (VE), respiratory gas-exchange ratio (RER), VO2, and VCO2 were measured continuously and heart rate and rate of perceived exertion (RPE) were collected each minute. RESULTS: The mean overall variance of RER at the %VO2vt intensities was significantly less than at the %VO2max intensities (%VO2vt = 0.030±0.025, %VO2max = 0.041±0.029, p<0.001). The mean RER variance was not different between genders relative to %VO2vt (p>0.05). For males and females, the variance in RER was significantly less when evaluated at 70% and 90% of VO2vt than at 40% and 50% of VO2max respectively (p<0.001). When the RER mean variance values were compared at the 125%VO2vt vs. 65%VO2max, RER variance values within subjects (males, females and overall) were not different (p>0.05). Similar patterns in RER variance were seen when compared by body mass index (BMI) or fitness. CONCLUSIONS: Using % VO2vt is a viable method to prescribe exercise intensity during research and/or training, with overall lower RER variance, especially when the intensity of exercise is below the ventilatory threshold."],"dc:identifier":["https://scholarworks.umt.edu/etd/1164"],"dc:publisher":["University of Montana"],"dc:subject":["maximal oxygen consumption","RER","training","ventilatory threshold"],"dc:title":["Variability of substrate utilization during exercise relative to VO2vt and VO2max"],"dc:type":["Thesis"],"thesis:degree_name":["Master of Science (MS)"]},"updated_at":"2026-07-24T03:14:21Z"}