Can sports overtraining be prevented?

Department: Human Movement Sciences
Section: Physiology
Research area/-theme: overtraining, training load, sport, burnout
Researcher: Jos de Koning
In collaboration with: Médecins sans Frontières, Tour for Life


Unexplained fatigue and underperformance is a large problem in sports, daily life and work situations. The balance between stress and recovery (i.e. training load versus rest) is important for optimal performance. If the balance between training load and recovery is inappropriate, this might result in persistent physiological and/or psychological maladaptations. In sports literature this phenomenon is known as non-functional overreaching (NFOR) or overtraining syndrome (OTS). In daily life and work situations this imbalance between stress and recovery can manifest as burnout or chronic fatigue.

To investigate the balance between stress and recovery, we performed a large unfunded study using a natural occurring experimental model (measurements before, during and after an 8-day charity cycling tour for Médecins sans Frontières). Cyclists rode from Italy to the Netherlands, while passing the Alps, Jura, Vosges and Ardennes. This event is seen as one of the most physical challenging tours in amateur cycling. Based on testimonial evidence, this ecological sports model appears to simulate the process of overtraining, as many participants reported prolonged fatigue after the conclusion of the tour.

We have built up an extensive database of physiological and psychological data from the Tour for Life, with several subjects presenting evidence of NFOR/OTS. We are analyzing this database, and developing a general model for NFOR/OTS, particularly in terms of preventing NFOR/OTS, understanding who might be at risk, and the potential genetic determinants of risk. This experimental model should, in addition to giving specific insight into an important disorder to athletes, give more general insight into the broader problem of burnout syndrome.