The effect of ventilatory threshold in endurance and resistance training

Abstract

PURPOSE: With the growing rate of physical inactivity in the United States and around the world, the study of how to improve performance and increase the health benefits that come with exercise is increasing. There are many questions asked about the ventilatory threshold such as what point in time does the ventilatory threshold take place and how long is an individual able to exercise at a certain intensity before major fatigue happens? This brings me to my question, how is the ventilatory threshold affected when doing endurance or resistance exercise training? I looked at VO2 max stress test data to find where the ventilatory threshold occurs. I wanted to see if there is an increase in the ventilatory threshold of an individual through bouts of resistance and aerobic training. I am looking at the ventilatory threshold through different modes of exercise to see if it is an accurate indicator of one's cardiorespiratory fitness and what is the best method of calculating one's ventilatory threshold. This could also be vital knowledge during rehabilitation for a participant recovering from an injury or a participant wanting to improve their cardiorespiratory fitness level. The second purpose of this study was to determine whether there was a significant difference in the determination methods of finding the ventilatory threshold. METHODS: Three training groups: Sedentary, highly active Resistance Trained, and highly Active Endurance Trained performed a CPET on a cycle ergometer, and gas exchange was measured using a metabolic cart. Using the metabolic cart files, the ventilatory threshold was determined using the Ventilatory Equivalent method as the primary determinate with the secondary determinates being the V-Slope method, % VO2 max, and % maximal work rate (w). Once the VT was determined, four methods of determining VT were calculated in GraphPad Prism. The four determining methods that were calculated included the Ventilatory Equivalent, V-Slope, VE, and VCO2 methods. RESULTS: 59 participants participated in the CPET test and had their VT determined. There was a significant difference when comparing the Ventilatory Equivalent and VE methods for % VO2 max in the HART group. When comparing the group's % VO2 max, there was a significant difference using the Ventilatory equivalent method between all three groups. There was a significant difference between the Sedentary and HAET groups when doing a group comparison when looking at the % VO2 max using the VCO2. After comparing the groups using the % maximal work rate, there was a significant difference between all three groups for all four methods of determining the ventilatory threshold. CONCLUSION: The primary findings of the current study after observing the results of comparing the % VO2 max, the HART and HAET group had a higher % VO2 max. When comparing the % maximal work rate between the groups, the HAET group had a higher % maximal work rate compared to the sedentary and HART groups. When comparing what methods of determining VT, there was no significant difference between the methods. This states that any of the four methods could be a viable source to determine one's VT and participating in regular bouts of endurance or resistance training has improvements in VO2 max and CRF.