Effects of “living high-training low and high” on sleep, heart rate variability and psychological responses in elite female cyclists

“Living High-Training Low and High” (LHTLH) is a training method used to improve physical performance at sea level. The main concept is based on the combination of physiological adaptations related to chronic “Living High-Training Low” altitude residence with additional “Repeated-Sprint training in Hypoxia” (RSH). While the effects of hypoxia on psychophysiological responses and heart rate variability (HRV) are well documented for “Living High-Training High” or “Living High-Training Low”, there is a lack of knowledge for LHTLH, more specifically in elite female athletes. The aim of the present study was to investigate the effects of LHTLH on sleep, HRV, and psychological responses. Ten elite level female cyclists (mean age: 17.3 ± 1.2 years, VO2max: 54.9 ± 6.9 ml.min.kg-1) were monitored for 19 days divided into 3 periods: i) normoxia (5 days preceding LHTLH), ii) early acclimatization phase (day 1 to 4 of LHTLH) and iii) middle acclimatization (day 5 to 14) performed in hypoxic rooms (FiO2 = 15.09%). Sleep disturbance, sleep architecture, HRV, and psychological responses (stress, emotions, perseverance of effort and consistency of interest) were recorded during the 3 periods. The results found that, during the early acclimatization period, there was no significant difference in total sleep time, sleep efficiency, latency or waking, but a significant increase in the level of effort, sleep disturbance, alterations of HRV and sleep architecture with an increase in stages 1 and 2 of sleep. During the middle acclimatization period, the athletes had restorative sleep, but HRV remained altered, with an increase in external tension.