Author(s): DI PINTO, G., SARTOR, F., MARCELLI, L., BERTOLLO, M., DI FRONSO, S., CURZI, D., Institution: UNIVERSITÀ DEGLI STUDI GABRIELE D'ANNUNZIO CHIETI - PESCARA, Country: ITALY, Abstract-ID: 2121

INTRODUCTION:
Sleep monitoring is widely used in elite sport and is considered relevant for recovery and performance [1, 2]. In soccer, the demands of matches and busy schedules can negatively affect sleep, especially during competitive periods [3]. However, it remains unclear which objective actigraphy-based sleep features are most strongly associated with perceived sleep quality (SQ) and perceived recovery (TQR) across a season [1, 2]. The aim of this study is to identify actigraphy-based sleep metrics associated sleep and recovery perception and to compare outcomes across rest (R), training (T) and match days (MD).
METHODS:
In this longitudinal study, 19 elite female players monitored over three months of the regular season using actigraphy to assess sleep, while they provided daily morning ratings of Sleep Quality (SQ; 1-5) and Total Quality Recovery (TQR; 6-20) [4]. Actigraphy-based sleep features included total sleep time (TST, i.e., the time spent sleeping), sleep onset latency (SOL, i.e., the time required to fall asleep), number of awakenings (i.e., the count of awakening after falling asleep), and sleep regularity index (SRI, i.e., the possiblity of being in the same sleep-wake state at the same time on consecutive days) [5, 6]. Linear mixed models with athletes as random intercept tested all sleep features and day type (R; T; MD) as fixed effects. Predictors were centered around the sample median, and post-hoc comparisons were performed using Tukey’s adjustment.
RESULTS:
Higher SQ ratings were associated with longer TST (b=0.0041 per min, 95% CI 0.0030 to 0.0051, p<0.001) and SOL (b=0.0033 per min, 95% CI 0.0014 to 0.0052, p<0.001), with no evidence for awakenings or SRI. SQ was lower on MD than R and T (R-MD=0.366, p=0.012; T-MD=0.537, p<0.001). Higher TQR ratings were associated with higher TST (b=0.0058 per min, 95% CI 0.0033 to 0.0083, p<0.001), and SOL (b=0.0059 per min, 95% CI 0.0015 to 0.0104, p=0.009) and higher number of awakenings (b=0.047, 95% CI 0.0108 to 0.0832, p=0.011), while evidence for SRI was weak (p=0.073). TQR was lower on MD compared to both R and T (R-MD=1.580, p<0.001; T-MD=1.322, p<0.001).
CONCLUSION:
Across a season in elite female soccer, actigraphy-based sleep duration and latency were associated with daily ratings of SQ and TQR. Moreover, soccer players showed the lowest recovery and SQ perception during match days. TST emerged as a consistent correlate of both SQ and TQR. This supports specific planning to promote sleep opportunities and facilitate sleep initiation around match days, complemented by combined objective and subjective monitoring [1, 2, 5].
References
1 Fullagar et al., 2015 https://doi.org/10.1007/s40279-014-0260-0
2 Halson, 2014 https://doi.org/10.1007/s40279-014-0147-0
3 Thomas et al., 2021 https://doi.org/10.1123/ijspp.2020-0706
4 Kentta & Hassmen, 1998 https://doi.org/10.2165/00007256-199826010-00001
5 Leeder et al., 2012 https://doi.org/10.1080/02640414.2012.660188
6 Phillips et al., 2017 https://doi.org/10.1038/s41598-017-03171-4