Abstract
Twenty-two male soccer players (mean age 21.3yrs) performed an incremental, multistage
bicycle ergometer exercise test with work load increasing by 50W, until volitional
exhaustion. The exercise stages lasted 3 min and were separated by 1 min resting periods.
Before exercise and during each load an audio-visual five-choice reaction task was
administered to assess subjects' psychomotor performance. During resting intervals
venous blood samples were taken for lactate (LA), adrenaline (A) and noradrenaline
(NA) determinations. It was found that reaction time (RT) decreased gradually during
exercise reaching its minimum (approx. 87% of pre-exercise value) at load 236W (approx.
75% V̇O2max, HR 164 beats/min). Then, it increased rapidly, exceeding the resting level by
18%). The work load and heart rate (HR) associated with the minimal RT were higher
(p<0.001) than work load and HR associated with the LA threshold (by 46W and 17 beats/min,
respectively). Plasma A and NA showed an exponential increase during exercise with
thresholds at 204 and 208W, respectively (HR 149 and 154 beats/min). Work load at
which plasma NA threshold occurred was significantly higher than the LA threshold
but it did not differ from the work load associated with the minimal RT. Conversely,
plasma A threshold was lower than the load of the minimal RT but did not differ significantly
from LA threshold. It is concluded that young athletes continue to improve their psychomotor
performance during exercise even at heavy work loads exceeding anaerobic, and plasma
adrenaline thresholds. A relationship between reaction time and plasma catecholamines
fits the U-shape curve.
Key words
Psychomotor performance - exercise - anaerobic threshold - blood lactate - plasma
catecholamines
