Effect of Cadence on Respiratory Response During Unloaded Cycling in Healthy Individuals

• Main Authors: Jastrzębska Agnieszka D., Kowalski Marcin
• Format: Article
• Language: English
• Published: Termedia Publishing House 2015-03-01
• Series: Human Movement
• Subjects: breathing pattern; cycling; work rate; ergoreceptors
• Online Access: http://www.degruyter.com/view/j/humo.2015.16.issue-1/humo-2015-0025/humo-2015-0025.xml?format=INT

Purpose. The aim of the study was to establish the respiratory response to unloaded cycling at different cadences. Methods. Eleven healthy participants performed a maximal graded exercise test on a cycle ergometer to assess aerobic fitness (maximal oxygen consumption: 46.27 ± 5.41 ml · min-1 · kg-1) and eight 10-min unloaded pedaling (0 W) bouts at a constant cadence (from 40 to 110 rpm). Respiratory data were measured continuously during each effort and then averaged over 30 s. Blood samples were collected before and 2 min after each effort to monitor changes in acid-base balance. Results. The efforts were performed at an intensity of 16.5-37.5% VO2peak. Respiratory response was not differentiated in cadences of 40, 50, 60 rpm. From 70 rpm, an increase in cadence was significantly associated with increased minute ventilation (F = 168.11, p < 0.000) and oxygen consumption (F = 214.86 p < 0.000) and, from 80 rpm, respiratory frequency (F = 16.06, p < 0.001) and tidal volume (F = 54.67, p < 0.000). No significant changes in acid-base balance were observed as a result of difference cadences. Conclusions. Unloaded cycling at a cadence of 70 rpm or above has a significant effect on respiratory function and may be associated with the involvement of large muscle ergoreceptors (mechanoreceptors) stimulated by the frequency of muscle contractions.