| Sleep heart rate has been suggested to provide a physiological marker for the detection of fatigue states associated with overtraining (Jeukendrup, Hesselink, Snyder, Kuipers, & Keizer, 1992). The large inter-individual variation in this measure indicates that a group research design may not be the most appropriate methodology for studying the effects of overtraining on the sleep heart rate.;It is concluded that the use of sleep heart rate is altered following over-reaching, but not during the actual process of over-reaching. Therefore, monitoring sleep heart rate alter a period of increased training may reveal when an athlete may return to training. Further research involving longer recovery phases and other physiological parameters that supplement sleep heart rate are required in order to determine the ultimate benefits from monitoring sleep heart rate in an over-reaching environment.;The purpose of this study was to examine the effects of an increased training load on the sleep heart rates of elite triathletes using a single-participant research design to determine their value in the detection of the early stages of overtraining. Training load was expressed as a daily training impulse (TRIMP) and increased 266% during an intervention phase compared to baseline. Sleep heart rate was recorded each night and was not altered during the intervention phase compared to a baseline phase. During the recovery phase, sleep heart rate was decreased compared to both baseline and intervention, suggesting that the participants developed the parasympathetic form of overtraining. |
