Abstract
The purpose of this investigation was to compare the effects of vibrations experienced
during off-road and road cycling. It was hypothesised that additional damping will
be expressed through a greater work demand and increased physiological markers when
travelling at the same speed over an identical terrain profile. Participants ascended
a tar-sealed road climb and a single-track off-road climb at a predetermined speed.
Time, speed, power, cadence, heart rate and V̇ O2 were sampled and logged every second while tri-axial accelerometers recorded accelerations
(128 Hz) to quantify vibrations experienced. Statistical analysis indicated accelerations
to be greater during the off-road condition (p<0.0001) with post-hoc analysis exposing
differences (p<0.001) for handlebar, arm, leg and seat post but not the lower back
or head. The increased accelerations during off-road riding are associated with the
increased vibrations and rolling resistance experienced. This led to increases in
the work done (road: 280±69 vs. off-road: 312±74 W, p=0.0003) and, consequentially,
a significant increase in the physiological markers V̇ O2 (road: 48.5±7.5 off-road 51.4±7.3 ml·kg−1·min−1, p=0.0033) and heart rate (road: 161±10 off-road 170±10 bpm, p=0.0001) during the
off-road condition. Such physiological differences and their causes are important
to understand in order to provide suitable training recommendations or technological
interventions for improving competitive performance or recreational enjoyment.
Key words
mountain biking - accelerometers - rolling resistance - cycling economy - performance
