acta facultatis educationis physicae universitatis comenianae

Assessment of pedalling techniques on a bicycle depending on intensity of training load
45
Testing was realized in laboratory conditions on the bicycle ergometer Ergocycle that
allows monitoring of tangential driving forces at frequency of 100 Hz. In the examinations
we used isokinetic mode. This regime is characterized by a constant speed ensured by the
special electromagnetic brake control system, which instantly adjusts resistance force acting
on the pedals so that the pedalling rate remains, regardless of the pedal force, constant.
For each individual we set saddle position and handlebars. Proband stood next to the
saddle, picked up the leg from the ground, so that the leg was in a horizontal position.
According to the upper edge, we set the seat height. Then he sat on the bike and seat height
was checked or adjusted to the upper thigh leg outstretched in the position of deadlock pedal
in a way so that it reached 145 to 155 degree angle (chosen limb slightly bent at the knee
joint). The handlebars were adjusted to the same height as the saddle; in case of the higher
subjects it was 2 – 5 cm below.
Both groups completed tests in sport footwear, which were mounted to the pedal with
the help of clips and baskets. To ensure standard conditions they performed tests of load in
saddle. Within the actual testing the probands went through one-minute load at a frequency
of 90 revolutions per minute gradually in the wattage of 100 watts, 200 watts and 300 watts.
Since performance in isokinetic mode depends on the subjective effort, selected intensity
load was maintained by adjusting (increasing or decreasing) of individual effort based on
immediate information on performance of subjects updated after each rotation on the ergometer
monitor. Finally, test subjects underwent a 10-second maximum effort load at a
frequency of 90 revolutions per minute.
For every one-minute load we used the software Ergocycle and this way we obtained
average minimum force (N), maximum force (N) and average force (N) of 360-degree cycle
of pedal revolution. When we subtracted the minimal force from the maximum force we got
the difference of force (N). When the average force divided the difference we got ratio that
we expressed in percentage (%) and called it equality pedalling coefficient. We compared
the differences between the two groups in the equality-pedalling coefficient, with the parametric
unpaired T-test.
Results and discussion
The results showed that the equality-pedalling coefficient of cyclists and non-cyclists
at load of 100 watts did not show significant differences (Fig. 4). We assume that this could
be due to too low intensity loads that cyclists hardly every use in training.
At the 200-watt load, we found significant difference (p < 0.05), where the cyclists
reached a coefficient of 120 ± 20 % and 138 ± non-cyclists 19 % (Fig. 4). It is this load that
is essential for cyclist's training. Average performance cyclist aerobic threshold is around
200 watts and the optimal frequency of revolutions around the 90 th .
Load at 300 watts confirmed a significant difference (p < 0.05) when the cyclists reached
the coefficient of 116 ± 17% and non-cyclists 134 ± 24 % (Fig. 4). For this load non-cyclists
have to spend a huge effort and are not able to maintain it for longer time. However, for the
performance cyclists this intensity presents anaerobic threshold, in which they spent most
time when racing or during time trials and training. (Vogt et al., 2006, Smith et al., 2001).
At 10-second maximum pedalling efforts no significant differences (p < 0.05) between cyclists
and non-cyclists (Fig. 4) were confirmed.
Acta Facultatis Educationis Physicae Universitatis Comenianae LII/I