Balancing stress and recovery in sports

To reach elite level in sports, athletes have to start their intensive and time-consuming training at an early stage. The road to the top is a stressful one, not only due to the physiological stress of training, but also caused by psychological and social stress. In order to improve performance athletes continuously challenge their personal boundaries. This may lead to a local or general overload of the human body that results into injuries, illnesses and overtraining. Overtraining is characterized by an unexplained decrement in sport-specific performance and is often coupled with symptoms such as increased fatigue, poor concentration, disturbed mood, and altered eating and sleeping patterns. Full recovery may take months to years. Monitoring stress and recovery may help to optimize performance and prevent a local or general overload. Clinical measurements showed that mood state and hormonal responses to a double maximal exercise protocol provided valuable information to confirm the diagnosis of overtraining.

Formative feedback for the coach reduces mismatch between coach and players’ perceptions of exertion

Objective: The aim of the present study was to investigate the influence of formative feedback for the coach on the agreement between intended, observed and perceived exertion in soccer. Methods: A quasi-experimental study design was conducted using a feedback intervention. Agreement between coach and players was assessed with and without feedback. The coach filled in the Rating of Intended Exertion (RIE) before training and the Rating of Observed Exertion (ROE) after the training for all individual players. Twelve U23 (age 20.3 ± 1.5; height 180.5 ± 4.8 cm; weight 74.8 ± 6.6 kg) soccer players registered Rate of Perceived Exertion (RPE). Furthermore, training duration (minutes), total distance (km), average speed (km·h−1), number of sprints, distance >14.4 km·h−1 (km), TRIMP and time >85% maximal heart rate (min) were collected. Results: About 231 RPEs were collected and paired with RIE and ROE of the coach. The average discrepancy between ROE and RPE, decreased from 1.0 ± 0.89 without feedback to 0.7 ± 0.73 with feedback (p < 0.003, ES 0.4). Further analyses revealed that this reduction in mismatch was particularly present in hard training sessions (p < 0.004, ES 0.6), but not for easy and intermediate sessions. The mismatch between RIE and RPE did not improve. Conclusions: The results indicate that feedback improves the ability of a soccer coach to observe individual player exertion for most players, with small to moderate effect sizes. The mismatch between intended and perceived exertion did not improve with feedback. The use of formative feedback about load to coaches is recommended, particularly after hard sessions

Anticipating Injuries and Health Problems in Elite Soccer Players Using Dynamic Complexity

BACKGROUND/AIM: Injuries and health problems of soccer players may appear abruptly and are often unexpected. However, hypotheses from complex systems theory suggest that these events can be preceded by certain Early Warning Signals (EWSs).1 We tested whether injuries and health problems can be anticipated with a specific type of EWS, that is, an increase in dynamic complexity (DC).2METHODS:Over two competitive seasons, we collected psychological and physiological self-reports (i.e., self-efficacy, motivation, mood, rating of own performance, enjoyment, and recovery) and data from heart rate sensors on every training and match day from 14 youth soccer players. We recorded time-loss injuries daily and players filled in the Sports Trauma Research Center Questionnaire on Health Problems (OSTRC-H2) once a week. We then calculated the DC of the self-reports and sensor data in a seven-day window to test for increased variability and complexity over time before injuries and health problems.RESULTS:Players experienced 5.6 injuries and 8.4 health problems on average across two seasons (range=1-18 and range=2-26, respectively). Results showed that increases in DC could often anticipate the occurrence of injuries and health problems. In 55% and 37% of the players DC increased up to five days before injuries and health problems, respectively (SD=39% and SD=25%, Min=0% and Min=0%, Max=100% and Max=83%).CONCLUSIONS:Results of this study suggest that EWSs can be used for real-time anticipation of injuries and health problems in daily soccer practice. Future research should test for the robustness of these results within and between individuals and perform sensitivity and specificity tests. In addition, finding out how warning signals can be communicated to soccer players and staff is an interesting avenue.REFERENCES1. Den Hartigh RJR, Meerhoff LRA, Van Yperen NW, et al. Resilience in Sports: A Multidisciplinary, Dynamic, and Personalized Perspective. Int Rev Sport Exerc Psychol. 2022. doi:https://doi.org/10.1080/1750984X.2022.20397492. Olthof M, Hasselman F, Strunk G, et al. Critical Fluctuations as an Early-Warning Signal for Sudden Gains and Losses in Patients Receiving Psychotherapy for Mood Disorders. Clin Psychol Sci. 2020;8(1):25-35. doi:10.1177/2167702619865969<br/