Aero position : aerodynamic optimization on the bike
BikeBody configuration on the bike aimed at reducing aerodynamic drag, the main resistance factor above 35 km/h.
Aerodynamics accounts for 70-90% of total resistance on the bike above 35 km/h. The aero position (elbows on aero bars, horizontal torso, low head) can save 10-20 minutes on an Ironman compared to an upright position. Key parameters: aero bar height and width, drop (saddle-to-bar height difference), saddle height, torso angle. A professional fitting is recommended before extended aero training periods. Caution: too aggressive a position hurts pedaling efficiency and the run off the bike.
In TriPaced:
In TriPaced, long bike sessions include progressive aero position blocks to accustom the back and hips. The app indicates recommended aero duration based on the training phase.
Source Debraux P. et al., 2011 : Aerodynamic drag in cycling - methods of assessment (Sports Biomechanics)