Effect of overreaching on cognitive performance and related cardiac autonomic control O. Dupuy 1,2 , M. Lussier 3,4 , S. Fraser 3,4 , L. Bherer 3,4 , M. Audiffren 1 , L. Bosquet 1,2,3 1 Faculty of Sport Sciences, University of Poitiers, Poitiers, France, 2 Department of Kinesiology, University of Montreal, Montreal, QC, Canada, 3 Research Center, Montreal Institute of Geriatrics, Montreal, QC, Canada, 4 Department of Psychology, University of Quebec at Montreal, Montreal, QC, Canada Corresponding author: Laurent Bosquet, PhD, Faculty of Sport Sciences, University of Poitiers, 8 Jean Monnet Road, 86000 Poitiers, France. Tel: +33 (0) 549 453 340, Fax: +33 (0) 549 453 396, E-mail: laurent.bosquet@univ-poitiers.fr Accepted for publication 9 March 2012 The purpose of this study was to characterize the effect of a 2-week overload period immediately followed by a 1-week taper period on different cognitive processes including executive and nonexecutive functions, and related heart rate variability. Eleven male endurance ath- letes increased their usual training volume by 100% for 2 weeks, and decreased it by 50% for 1 week. A maximal graded test, a constant speed test at 85% of peak tread- mill speed, and a Stroop task with the measurement of heart rate variability were performed at each period. All participants were considered as overreached. We found a moderate increase in the overall reaction time to the three conditions of the Stroop task after the overload period (816  83 vs 892  117 ms, P = 0.03) followed by a return to baseline after the taper period (820  119 ms, P = 0.013). We found no association between cognitive performance and cardiac parasympathetic control at baseline, and no association between changes in these measures. Our findings clearly underscore the relevance of cognitive performance in the monitoring of overreach- ing in endurance athletes. However, contrary to our hypothesis, we did not find any relationship between executive performance and cardiac parasympathetic control. Nonfunctional overreaching (NFOR) in sport is a complex state, which appears when an imbalance exists between training/non-training stress and recovery. It is characterized by a transitory decrease in sport perform- ance and may eventually lead to the development of an overtraining syndrome (OTS) if training load is not adjusted to the level of fatigue. Early detection repre- sents therefore a cornerstone in the monitoring of NFOR. Unfortunately, the etiology is still poorly under- stood and there is no pathognomonic marker that is widely accepted by physicians and sport scientists (Meeusen et al., 2006). Besides the decrease in sport performance, one of the most accessible and relevant symptoms of NFOR or OTS is a psychological disturbance characterized by negative affective states (Morgan et al., 1987; O’Connor et al., 1989; Raglin et al., 1991). The Profile Of Mood States (POMS) (Mac Nair et al., 1971) and the Recovery–Stress Questionnaire (RESTQ) are two valid and commonly used psychological tools (Kellmann & Kallus, 2001) that consistently showed a dose–response relationship between observed scores and training load as well as a close association with performance (Dupuy et al., 2010). While psychological symptoms have been early recognized as possible signs of training maladap- tation, the role of the central nervous system and higher brain centers in the development of fatigue and NFOR has received little attention (Meeusen, 1999). Psychomotor speed and cognitive performance are considered as indirect measures of cerebral functioning, and have been proposed as early markers of NFOR and OTS (Nederhof et al., 2006). The study by Rietjens et al. (2005), provided some support to this hypothesis, because they found increased reaction time (RT) in seven well-trained cyclists after a 2-week period of overload. However, these cyclists could not be consid- ered as overreached, because their performance during the graded exercise test or during the constant intensity test was not altered by the overload period. Nederhof et al. (2007) measured RT before and after a ~9-day training camp in 12 well-trained cyclists. Five of them were considered as functional overreached based on physiological and subjective measures, while the seven remaining cyclists were considered as well-trained. Nederhof et al. (2007), observed an increased RT in overreached cyclists, but the difference was not statis- tically significant. Hynynen et al. (2008), reported a larger number of errors during the Stroop color word test in 12 athletes suffering from NFOR or OTS when compared with their 12 well-trained counterparts. Scand J Med Sci Sports 2012: ••: ••–•• doi: 10.1111/j.1600-0838.2012.01465.x © 2012 John Wiley & Sons A/S 1