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Factors related to cycling performance

Description: There were two primary goals in this investigation. The first goal was to determine if results from field tests (time-trials and a Conconi incremental test) are related to performance in mass-start long-distance bicycle races. The second goal was to investigate inter-relationships among field test variables. The testing variables measured were critical velocity (CV), Conconi anaerobic threshold (AT) velocity, 4mM AT velocity, fatigue index, peak blood lactate, and anaerobic work capacity. Participants were USCF 30 category 1 through 5 cyclists. Participants performed one 20.75 km and two 10.37 km all-out tests in the field. They also performed an incremental test. The tests were performed at one-week intervals. Results from the field tests were compared to recent mass-start racing performance. Results indicated that Conconi AT velocity was related to performance in a 161-km race. There was also a relationship between 4mM AT velocity and CV and between Conconi AT velocity and 4mM AT velocity. It was concluded that field tests might provide information about performance ability in mass-start long-distance bicycle races.
Date: May 2001
Creator: Naukkarinen, Vesa
Partner: UNT Libraries

Use of repeated tests and rolling breath averages affects the precision of quantifying the VO2 response profile in moderate intensity cycling.

Description: The purpose of this study was to determine whether working in the field of deaf education, as opposed to general education, results in a higher level of technology integration. A secondary goal was to determine if deaf educators who are deaf integrate technology at a higher level than their hearing counterparts. The instrument chosen for this study was the LoTi Technology Use Profile, a tool used to explore the role of technology in the classroom. A total of 92 participates were included in the study of which 48 were regular educators and 44 were deaf educators. The participants were selected from a population pool whereby teachers were presumably pre-disposed to using technology based upon their attendance at a technology training session in the form of a conference or a class. Deaf educators as a whole did not perform as well as general educators on the LoTi scales. Given the fact that the technology-minded general educators who comprised the sample population of this study scored exceptionally high on the LoTi scales, further research is needed to ensure comparability between the two groups. The findings of the current study do suggest, though, that deaf educators who are deaf have the potential to integrate technology to a greater degree than deaf educators who are hearing. Thus, a primary recommendation is to conduct a national LoTi survey of typical, rather than technology-minded, deaf educators as a comparison to the 2004 national survey of typical general educators.
Date: August 2006
Creator: Pedini, Daniela Marie
Partner: UNT Libraries

VO2 response profile in heavy intensity cycling after heavy intensity arm or leg exercise.

Description: The elevated CO2 levels, elevated temperature, and lower blood pH that may occur during exercise should enhance O2 delivery to the exercising muscles. It was hypothesized that performance of prior exercise (PE) would result in a faster VO2 response, as well as a reduced slow component contribution, in subsequent exercise bouts. Five women (21 ± 1 yr) and 10 men (23 ± 2 yr) performed nine 6-min bouts of heavy intensity cycle ergometer exercise (i.e., above the ventilatory threshold, individually determined by an incremental test). Three bouts were performed without prior heavy exercise (noPE), three were performed 6 min after a 6-min bout of heavy intensity arm cranking (PEA), and three were performed 6 min after a 6-min bout of heavy intensity cycle ergometer exercise (PEL). Breath-by-breath VO2 data from each of the three sets of three tests were combined and fitted to a two-component model, which ignores the cardiodynamic phase. The primary and slow component amplitudes were truncated to reflect actual increases in VO2 in each phase. The effects of PE on the time constant of the primary component were inconsistent. As hypothesized, the amplitude of the slow component was reduced by PE (noPE vs PEA vs. PEL: 25% > 16% < 14%; p < .05). It is concluded that heavy intensity PE affects characteristics of the VO2 profile in a subsequent bout of heavy intensity leg exercise.
Date: December 2006
Creator: Ptak, April Louise
Partner: UNT Libraries

Treadmill validation of the Siconolfi step test.

Description: Maximal oxygen uptake (VO2max) is the internationally recognized measure of a person's cardiorespiratory fitness. Currently the most accurate way of assessing one's true VO2max involves the use of maximal exercise tests, which require the use of specialized equipment, and are time consuming and costly. The purpose of this study was to determine the validity of the submaximal Siconolfi step test to estimate VO2max. A second purpose was to determine if body fat percentage improved the validity. Thirty-six individuals underwent a maximal treadmill test, in which VO2max was directly measured, and the step test. Results indicate that, although VO2max estimates generated by the Siconolfi step test are highly correlated to true VO2max (r =.887; p<.01), the values consistently underestimated a person's aerobic fitness. It was also determined that body fat percentage did not contribute to the prediction of VO2max.
Access: This item is restricted to the UNT Community Members at a UNT Libraries Location.
Date: May 2005
Creator: Harkrider,Tiffani L.
Partner: UNT Libraries

Evaluating the Pulse Sensor as a Low-Cost and Portable Measurement of Blood Pulse Waveform

Description: This study was aimed at determining whether the digital volume pulse waveform using the Pulse Sensor can be used to extract features related to arterial compliance. The Pulse Sensor, a low-cost photoplethysmograph, measures green light reflection in the finger and generates output, which is indicative of blood flow and can be read by the low-cost Arduino UNO™. The Pulse Sensor code was modified to increase the sampling frequency and to capture the data in a file, which is subsequently used for waveform analysis using programs written in the R system. Waveforms were obtained using the Pulse Sensor during two 30-s periods of seated rest, in each of 44 participants, who were between the ages of 20 and 80 years. For each cardiac cycle, the first four derivatives of the waveform were calculated and low-pass filtered by convolution before every differentiation step. The program was written to extract 19 features from the pulse waveform and its derivatives. These features were selected from those that have been reported to relate to the physiopathology of hemodynamics. Results indicate that subtle features of the pulse waveform can be calculated from the fourth derivative. Feature misidentification occurred in cases of saturation or low voltage and resulted in outliers; therefore, trimmed means of the features were calculated by automatically discarding the outliers. There was a high efficiency of extraction for most features. Significant relationships were found between several of the features and age, and systolic, diastolic, and mean arterial blood pressure, suggesting that these features might be employed to predict arterial compliance. Further improvements in experimental design could lead to a more detailed evaluation of the Pulse Sensor with respect to its capability to predict factors related to arterial compliance.
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Date: May 2016
Creator: Smithers, Breana Gray
Partner: UNT Libraries

The Effect of Mode and Intensity on Vo2 Kinetics in the Severe Intensity Domain

Description: The purpose of this study was to evaluate the effect of mode and intensity on VO2 kinetics in the severe intensity domain. Seventeen participants completed 3-7 tests each on a cycle ergometer and treadmill. For each test, Tfatigue, VO2max, Tmean response, VO2GAIN, TVO2max and T@VO2max were determined. Linear regression techniques were used to describe the relationship between TVO2max and Tfatigue . VO2max values were higher in running. The VO2 response profile was faster for running than cycling and faster at higher intensities. The faster VO2 response in running may be associated with larger active muscle mass or differences in muscle activation patterns. The faster response at higher intensities may suggest that VO2 response is driven by O2 demand.
Date: May 2000
Creator: Updyke, Rhonda S.
Partner: UNT Libraries

The Effect of Steroid Dose Regimen on the Relationship Between Lower Extremity Muscle Function and Cardiac Function in Post Heart Transplant Patients

Description: Differences in cardiovascular/aerobic function in heart transplant patients might be attributed to the rate of corticosteroid withdrawal and/or to skeletal muscle function. This hypothesis was tested among nine male, cardiac transplant recipients. Prednisone dosage was monitored, and isokinetic strength testing was performed at 4 different time periods throughout the first year post-transplantation. Cardiovascular/aerobic measurements were obtained at the fourth time period. Pre-surgery characteristics were obtained from the patient's medical record. Significant Pearson-product moment correlations were only found between muscle function and aerobic function and between pre-surgery characteristics and cardiovascular/aerobic performance. The results of this study show no evidence that rapid reduction of prednisone dosage enhances aerobic function by benefiting skeletal muscle function.
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Date: May 2001
Creator: Galatas, Mary V.
Partner: UNT Libraries

Minimum levels of physical activity and perceived quality of life.

Description: The purpose of this study was to examine the association between engaging in minimum levels of physical activity as defined by ACSM and perceived quality of life. A total of 43 college students were included in a repeated measures, quasi-experimental design research study that produced an overall retention rate of 65%, which resulted in 15 students being placed in the treatment group, and 28 students being placed in the control group. Analysis of variance with repeated measures was used to compare the quality of life mean scores over three administrations of the Quality of Life Inventory (QOLI), which resulted in no significant main effects for either the time measure or the group measure, but did produce a significant interaction effect. Post hoc analyses showed there was a significant difference between the treatment and control groups' quality of life mean scores only during the second administration of the instrument. Further analysis showed that the control group had significantly higher quality of life domain scores for six of the 16 quality of life domains. There were no significant differences between groups across any of the physiological measures. These findings did not support previous research that increasing individuals' level of physical activity will enhance their perceived quality of life. Instead, this study only provokes more questions about the connection between physical activity and perceived quality of life.
Date: May 2008
Creator: Carothers, Cathleen de Souza Lourenco
Partner: UNT Libraries

Oxygen Uptake Kinetics in Severe Intensity Exercise

Description: The purpose of this study was to describe mathematically the oxygen uptake kinetics during cycle ergometry, and to examine the effect of intensity on the kinetic responses within the severe domain. Sixteen volunteers performed a series of exercise tests at a range of intensities selected to elicit fatigue in ~3 to 10 min. A simple mono-exponential model effectively described the response across all intensities. There was a positive correlation between the response time and the time to fatigue, demonstrating that the maximal oxygen uptake was achieved faster at higher intensities within the severe domain. Models incorporating two components effectively described the responses only in tests lasting 8 min or more. It was concluded that there is a second, slow component in the oxygen uptake response only at the lower intensities within the severe domain.
Date: May 2000
Creator: Blumoff, Sonja
Partner: UNT Libraries

Effect of Chronic Alcohol Abuse and Resistance Training on the Skeletal Muscle Androgen Receptor Concentration of Rats

Description: The purpose was to examine the effect of chronic alcohol abuse on the androgen receptor content (AR) in skeletal muscle, and to determine if this effect was influenced by resistance training. Thirty-four male rats (456 ± 1 g; mean ± SE) were divided into 4 groups: Sham exercise-Ethanol, Sham exercise-Normal diet, Exercise-Ethanol, and Exercise-Normal diet. Both Exercise groups underwent a 6-week "squat" resistance training protocol and both Ethanol groups received an alcohol-rich diet throughout the 6-week period. Western blot analysis showed no effect of alcohol or resistance training on the AR of the extensor digitorum longus. For the rectus femoris, alcohol caused a decline in the AR (p=0.01). This reduction was not attenuated by resistance training. The AR of the soleus was not affected by chronic alcohol abuse alone; however, the resistance training induced increase in the AR was prevented by chronic alcohol abuse (p=0.03).
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Date: August 2004
Creator: Vingren, Jakob L.
Partner: UNT Libraries

The Acute Hormonal Response to the Kettlebell Swing Exercise

Description: The purpose of this investigation was to examine the acute hormonal response to a bout of kettlebell swing exercise. Ten healthy men (19-30 y, 23.6 ± 3.5 y, 174.6 ± 5.7 cm, 78.7 ± 9.9 kg) who were engaged in resistance training at least twice per week but were inexperienced with kettlebell swings participated in this study. Participants were familiarized with the kettlebell swing exercise during an initial visit. During the subsequent experimental protocol visit, participants performed 12 rounds of 30 seconds of 16-kg kettlebell swings alternated with 30 seconds of rest. Heart rate (HR) and rating of perceived exertion (RPE) were measured at the end of every round of swings. Fasted blood samples were collected pre-exercise (PRE), immediately post (IP), 15 minutes post (P15), and 30 minutes post exercise (P30) and analyzed for total testosterone (T), growth hormone (GH), cortisol, and lactate concentrations. Participants completed a total of 227 ± 23 swings (average swings per round: 19 ± 2). HR and RPE increased significantly (P < 0.05) throughout the exercise protocol. Lactate concentrations were significantly increased at all post exercise time points compared to PRE. T was significantly increased at IP compared to PRE. GH was significantly increased at IP, P15, and P30 compared to PRE. Cortisol was significantly increased at IP and P15 compared to PRE. 12 rounds of 30 seconds of kettlebell swing exercise induced an acute increase in T, GH, and cortisol concentrations in resistance trained men. Additionally, this exercise protocol induced a large increase in HR and lactate concentration. Thus, the kettlebell swing exercise might provide an effective method for simultaneous endurance and resistance training.
Date: December 2013
Creator: Budnar Jr., Ronald Gene
Partner: UNT Libraries

Hormonal Response to Free Weight and Machine Weight Resistance Exercise

Description: No study has examined the effect of exercise modality (free weight vs. machine weight) on the acute hormonal response using similar multi-joint exercises. The purpose of this investigation was to examine the effect of resistance exercise modality on acute hormonal responses by comparing the squat and leg press which are multi-joint, and similar in action and lower-body muscle involvement. Ten resistance trained men (21-31 y, 24.7 ± 2.9 y, 179 ± 7 cm, 84.2 ± 10.5 kg) participated in the study. Sessions 1 and 2 determined the participants’ 1-RM in the squat and leg press. During acute heavy resistance exercise testing visits (AHRET), sessions 3 and 4, participants completed 6 sets of 10 repetitions with an initial intensity of 80% of their 1-RM for the squat and leg press exercises. There was a 2 minute rest period between each set. Blood samples were collected before, immediately after, and 15 and 30 minutes after exercise via intravenous catheter during the AHRET visits and were analyzed for testosterone, cortisol, and growth hormone. Lactate, plasma volume change, heart rates and ratings of perceived exertion were also measured. Total work was calculated for external load only and for external load and the body mass used in the exercises. The 4 sessions were counterbalanced and randomized for exercise mode. Testosterone for the squat (Pre: 23.9 ± 8.7 nmol•L-1; IP: 31.4 ± 10.3 nmol•L) and leg press (Pre: 22.1 ± 9.4 nmol•L-1; IP: 26.9 ± 7.8 nmol•L) increased but more significantly after the squat. Growth hormone increased in both the squat (Pre: 0.2 ± 0.2 µg/L; IP: 9.5 ± 7.3 µg/L) and the leg press (Pre: 0.3 ± 0.5 µg/L; IP: 2.8 ± 3.2 µg/L). The increase was significantly higher after the squat compared to the leg press. Cortisol also increased after performing the squat (Pre: ...
Date: August 2012
Creator: Shaner, Aaron Arthur
Partner: UNT Libraries

Mechanisms Affecting Bench Press Throw Performance while Using a Counter-Balanced Smith Machine

Description: The use of a counter-balance weight system of a Smith machine affects measures of bench press throw performance. Twenty-four men performed bench press throws at 30% of their one-repetition maximum under four different conditions: 1) counter-balance and rebound movement (RC), 2) no counter-balance and rebound movement (RNC), 3) counter-balance and concentric only movement (CC), and 4) no counter-balance and concentric only movement (CNC). Peak power, force, and concentric and eccentric velocities were measured using a linear accelerometer; and peak ground reaction force (GRF) was measured using a forceplate. Peak measures for concentric and eccentric velocities showed that NCB> CB and RBT > CBT. Peak GRF measures showed CB > NCB and RBT > CBT. The lower performance measures for CB were likely due to an increase in the net external load when the barbell accelerates faster than the gravitational constant causing the counter-balance weight becomes ineffective.
Date: May 2011
Creator: Buddhadev, Harsh
Partner: UNT Libraries

Effect of Resistance Training on Cytokines in Hiv+ Men with Chemical Dependence

Description: Human immunodeficiency virus (HIV) and substance abuse (drug and/or alcohol) independently impair the immune system; importantly, the combination of HIV infection and substance abuse might produce more than an additive effect on this system. Tumor necrosis factor-alpha (TNF-?) and Interferon gamma (IFN?) are pro-inflammatory cytokines involved in differentiation of Th0 cells into Th1 cells. Interleukin 4 (IL-4) and Interleukin 10 (IL-10) are anti-inflammatory cytokine involved in differentiation of Th0 cells to Th2 cells. Unbalanced Th1 and Th2 cells can lead to immune suppression. Thus, changes in these cytokines could have important implications for people infected with HIV (HIV+). Resistance training can counteract muscle wasting, improve strength, and improve muscle mass. The purpose of this study was to examine the effect of resistance training on resting concentrations of circulating TNF-?, IFN-?, IL-4, and IL-10. Sixteen men (42 ± 11 years, 180.4 ± 9.1 cm, 89.2 ± 20.7 kg) infected with HIV and enrolled in an intensive 60-day in-patient substance addiction/abuse treatment program were recruited shortly after admission to the treatment facility. Participants were assigned to one of two groups using randomization: supervised resistance exercise 3 times per week using a progressive and non-linear periodized program (Exercise) or no exercise training (Non-Exercise) for six weeks. Before (Pre) and after (Post) the 6-week period, resting and fasted blood samples were obtained and analyzed for serum TNF-?, IFN-?, IL-4, and IL-10 concentrations using a high-sensitivity ELISA. TNF-? did not change following the 6-week period for Exercise (Pre: 4.8 ± 2.7 pg·ml-1; Post: 4.6 ± 2.4 pg·ml-1) or Non-Exercise (Pre: 3.0 ± 1.3 pg·ml-1; Post: 2.7 ± 0.8 pg·ml-1). IFN-?, IL-4, and IL-10 concentrations were below detectable limits. No adverse effects of the intervention were reported. A six-week resistance training program does not elicit changes in circulating TNF-? concentrations in men infected with HIV and ...
Date: May 2012
Creator: Curtis, John Harper
Partner: UNT Libraries