Changes in Choice Reaction Time During and After 8 Days Exhaustive Cycling are not Related to Changes in Physical Performance

PURPOSE: Reaction time has been proposed as a training monitoring tool, but to date results are equivocal. Therefore, it was investigated whether reaction time can be used as a monitoring tool to establish overreaching.

METHODS: The study included 30 subjects (11 female/19 male, age: 40.8±10.8 y, VO2max: 51.8±6.3 ml/kg/min) who participated in an 8-day cycling event. The external exercise load increased approximately 900% compared to the preparation period. Performance was measured before and after the event using a maximal incremental cycling test. Subjects with decreased performance after the event were classified as functionally overreached (FOR), others as acutely fatigued (AF). A choice reaction time test was performed 2 weeks before (pre), 1 week after (post) and 5 weeks after (follow-up), as well as at the start and end of the event.

RESULTS: Fourteen subjects were classified as AF and 14 as FOR (2 subjects were excluded). During the event, reaction time at the end was 68 ms (95% CI [46, 89]) faster than at the start. Reaction time post event was 41 ms (95% CI [12, 71]) faster than pre, and follow-up 55 ms faster (95% CI [26, 83]). The time by class interaction was not significant during (p=.26) and after (p=.43) the event. Correlations between physical performance and reaction time were not significant (all p>.30).

CONCLUSIONS: No differences in choice reaction time between AF and FOR subjects were observed. It is suggested that choice reaction time is not valid for early detection of overreaching in the field.