Effectiveness of endurance training guided by oxidative stress analysis

Introduction: The purpose of this study was to assess the effectiveness of endurance training guided by oxidative stress analysis. Methods: Twenty-three endurance athletes were randomized into an oxidative stress guided training group (guided, n = 12) and a control predefined training group (control, n = 11). At the end of a baseline week, a performance pre-test was performed before starting a 4-wk protocol followed by a post-test. Sleep duration, O2 score, subjective fatigue, training load and stress score were recorded daily. Heart rate variability (HRV) was measured three times a week. The training adjustment in the guided group was based on individual changes in O2 score values combined with the subjective fatigue. If the O2 score value was higher or lower than the individual recovery zone (calculated by the redox sensor) combined with a high total score of fatigue, a lower training load or rest was prescribed. The control group followed the standard predefined training program. Results: There was a significant (F = 2.45; P = 0.02) group x time interaction for O2 score. The average training volume was lower in the guided group in comparison to the control group (w3: P = 0.029, w4 P= 0.008). O2 scores were in both groups correlated with the training volume (R = 0.82, P < 0.05), RMSSDSU (R = 0.69, P < 0.05) and HRSU (R = -0.91, P < 0.001). However, no performance change was observed in both guided and control groups (pre-to-post- change 0.4 vs. -0.2%). Conclusion: As expected, daily individualized adjustment of the training loads based on oxidative stress stabilized the O2 score in the guided group while it continued to increase in the control group. Aerobic performance remained unchanged in both groups despite a lower training volume in the guided group. Of interest is the correlation between the O2 score values and the training volume. These two parameters are also related with some HRV parameters. Overall, the O2 score seems sensitive to training volume and direct or indirect markers of fatigue. Therefore, the redox sensor may be a practical tool for monitoring endurance training.

This thesis assesses endurance training effectiveness using oxidative stress analysis.