Award Date

December 2023

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Interdisciplinary Programs

First Committee Member

John Mercer

Second Committee Member

Julia Freedman Silvernail

Third Committee Member

James Navalta

Fourth Committee Member

Nancy Lough

Number of Pages

76

Abstract

Introduction: Bicycles have been around since the early 19th century. Since the invention of the bicycle, it has taken on several purposes. People have used bicycles as a means of transportation, leisure, exercise, and sport. The number of individuals who participate in a cycling event per year has increased. With the increase in popularity, research related to cycling has also increased. Research related to the physiology and biomechanics of cycling are of particular areas of interest. Balance is a crucial component of understanding why we cycle a certain way. Some research has labeled balancing on a bicycle as cycling sway. However, limited research has examined the influence of balance on the physiology or biomechanics of cycling. Therefore, the purpose of this study was to understand whether or not the potential to sway influences physiological and biomechanical measures. Methods: Thirteen participants (age = 24.9 ± 6.5 years; height = 1.7 ± 0.1 m; body mass = 64.7 ± 11.2 kg; mean ± SD) volunteered for the study. The participants completed two submaximal-graded cycling tests on a stationary smart bike placed on a rocker board. One condition allowed the participants to cycle freely and maneuver the bike side-to-side (unblocked). The second condition had blocks placed in the rocker board to keep the bike stationary (blocked). The order of the conditions was counterbalanced. Prior to completing the two cycling protocols, participants performed a preferred power phase. During this phase, participants were informed of the rate of perceived exertion (RPE) scale. Participants were instructed that during this phase, their power output for an RPE of 11 (‘fairly light’), 13 (‘somewhat hard’), 15 (‘hard’), and 17 (‘very hard’) would be determined. To accomplish this, the researcher increased and/or decreased the power until the resistance felt fairly light (RPE 11) while the participant cycled for roughly one to two minutes at this power while the board was unblocked. Once the power was determined, the participants repeated this two additional times for fairly light and the researcher averaged the three trials. This process was repeated for the other three RPE intensity levels. During the two conditions, participants performed each level of intensity for three minutes and continuously (12 minutes per condition). During each condition, heart rate (bpm), rate of oxygen consumption (V̇ O2; ml·kg1·min-1), sway (radians), cadence, speed, power, and RPE (11, 13, 15, 17) were measured. For heart rate and V̇ O2, the last minute of the three minutes was averaged. For sway data, 30 seconds were recorded for each intensity. From the 30 seconds, local maximums in each direction (i.e., right, left rotations) were identified for each intensity level. The right and left sway maximums were each averaged. Results: Sway reported a statistically significant difference in the main effect of condition (p<.001). The rate of oxygen consumption, heart rate, and speed reported statistically significant differences in the main effect of intensity levels (p<.001). For sway, the VO2, heart rate, speed, distance, and cadence, there was no statistical interaction between condition and intensity (p>.05). Conclusions: Physiological measures were not influenced by the ability to sway with power matching. Sway was different between SWAY conditions regardless of INTENSITY. For the rate of oxygen consumption, heart rate, speed, and distance, values increased between INTENSITY levels (RPE 11, 13, 15, 17) for each condition. These findings are reasonable due to the graded cycling protocol and the blocked/unblocked conditions. Sway was different between conditions since the blocked condition restricted the bike’s lateral movement and the unblocked allowed sway movement. Power increased between each intensity level and since the intensity levels were performed continuously, adapting to the change in power led to increases in physiological demand. While this study allowed for any experience of cyclists, the majority of subjects were novices. Future studies should consider examining different levels of experienced cyclists to see if they respond similarly.

Keywords

Balance; Endurance; Sports

Disciplines

Biomechanics | Medical Physiology | Physiology

Degree Grantor

University of Nevada, Las Vegas

Language

English

Rights

IN COPYRIGHT. For more information about this rights statement, please visit http://rightsstatements.org/vocab/InC/1.0/

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