AUTHOR=Evans Stuart A. , James Daniel , Rowlands David , Lee James B. 

TITLE=Variability of the Center of Mass in Trained Triathletes in Running After Cycling: A Preliminary Study Conducted in a Real-Life Setting

JOURNAL=Frontiers in Sports and Active Living

VOLUME=Volume 4 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/sports-and-active-living/articles/10.3389/fspor.2022.852369

DOI=10.3389/fspor.2022.852369

ISSN=2624-9367

ABSTRACT=While short-distance (sprint) triathlon provides an opportunity to research the effect of the center of mass (CoM) when cycling and running, much remains to be done. The literature has failed to consistently or adequately report changes to hand position while cycling and the consequential effects to running. 
The data indicate that the cycle to run transition (T2) is important for overall race success. While many age-groupers participate in sprint distance triathlon, the lack of T2 based research make comparisons difficult. Unobtrusive wearable sensors have proven to be an informative resource to monitor the magnitude of CoM accelerations in running. However, the extent to which they are used in triathlon is unclear. Therefore, the aim of the present study was to analyse the magnitude of CoM acceleration when cycling position and cadence is changed and to analyse these effects during running after cycling. Ten recreational triathletes completed two 20 km cycling trials at varied cadence in a CycleDrops and CycleAero position followed by a 5 km run at self-selected pace. Torso kinematics were captured in a typical training setting using a triaxial accelerometer. CoM acceleration was quantified in m/s² and variability measured by the coefficient of variation (CV) and root mean square (RMS). Results from CycleAero indicated that longitudinal CoM acceleration (CV = 1%) and mediolateral acceleration (CV = 3%) was significantly reduced (p < 0.0001) compared to CycleDrops. As for RPE, a significant difference was observed with higher values observed in CycleAero alongside greater acceleration anteroposterior magnitude. The CoM varied significantly from RunAero as the trajectory consisted of less longitudinal (CV = 0.2, p < 0.0001) and mediolateral acceleration (CV = 7.5%, p < 0.0001) compared to RunDrops. Although greater longitudinal acceleration was observed in the initial 1 km epoch of RunAero, triathletes then seemingly adjusted their CoM trajectory to record lower magnitudes until completion of the 5 km run, completing the run quicker compared to RunDrops (22.56 min¹ ± 0.2, 23.34 min¹ ± 0.5, p < 0.0001, CV = 1.3%). The practical implication is that CoM variance inherent to the cycling position influences running to varying capacities.