Sport activities can be considered either in terms of sport consumption or sport dependence characterizing a behavioral addiction [1–3]. The objective of this study concerned the effects of exercise-induced sport dependence on soldiers stress resistance in the context of a six months deployment in Afghanistan.

In an anonymous prospective cohort study we assessed before during and six months after deployment Extra Regimental Sport consumption (ERS), exercise dependence (ED; 2,5), anxiety and depression diseases, perceived stress, and mood of Tension/Anxiety. Plasmatic Brain Derived Neurotrophic Factor (BDNF), considered as a good marker of central nervous system plasticity, was assessed before and after.

Among the 397 young soldiers evaluated before and during the deployment, 131 had been assessed six months after. Before deployment, 65% of soldiers have ERS consumption. 42% presented ED, which was not related with higher ERS consumption. Levels of perceived stress, anxiety and depression diseases were higher for ED subjects and were not influenced by ERS consumption. In soldiers without ED, perceived stress and mood of tension/anxiety were higher in subjects without ERS. Neither ERS consumption, nor ED altered BDNF concentration. During deployment, the percentage of ED was not modified, but the distribution in sport dependence group was modified: 64% of soldiers with ED were not identified as addicted before. After 3 months, soldiers presenting ED had a higher Mood of tension/anxiety level. After deployment, both a higher BDNF concentration and anxiety disease score were observed in soldiers developing ED refer to those who did not develop ED.

ED seems to present: (1) a relation with a high “anxiety”, (2) a liability in chronic stress environment. However, ED could be considered as an efficient strategy referred to the high level of BDNF after the mission. A follow-up is ongoing 18 months after the deployment to confirm this assumption.