Table 5.

Results concerning sleep and training load.

Study	Aim	Results	Findings
Clemente et al., [42]	To test the associations between wellness and internal and external load variables during two intermittent SSGs.	Large and negative correlations were found between sleep quality and RPE (−0.64, (−0.88; −0.14)) and total accelerations (−0.64, (−0.88; −0.13)) during 6 × 3′ small-sided games.	Sleep was also negatively and largely correlated with RPE during shorter bouts. Thus, coaches should adopt supplementary monitoring methods to avoid erroneous classifications of load rated by players with low sleep quality.
Clemente et al., [43]	To assess differences of playing position on s-RPE and Hooper Index across two different training microcycles (1 vs. 2 competitive games) and to examine the relationship between s-RPE and Hooper Index across an entire season.	Sleep quality was similar in the two different microcycles. Significative correlations between s-RPE and sleep were found (p = −0.109) in 2-matches microcycles.	Sleep was also negatively correlated with s-RPE, especially in microcycles with two matches, thus suggesting that congested periods that increase stress and muscle soreness are more sensitive to affect sleep quality.
Selmi et al., [44]	To assess the influence of well-being indices (sleep, stress, fatigue, and muscle soreness) and the total quality of recovery on technical and physiological measures during soccer SSGs.	No significant correlations were found between well-being indices, total quality recovery, and physiological parameters.	Physiological responses during SSGs (HR and Lactate) and its intensity were not influenced by the variability in sleep.
Watson and Brickson [45]	To determine whether acute TL and sleep are independent predictors of subjective well-being and whether sleep mediates the influence of acute TL on subjective well-being in female youth athletes.	Sleep duration mediated a significant portion of the effect of TL on mood (26.8%, p < 0.001), fatigue (12.6%, p < 0.001), and stress (24.5%, p < 0.001)	Among female youth athletes, decreased sleep duration and increased TL are independently associated with impairments in subjective well-being. In addition, decreased sleep mediates a significant portion of the negative effect of increases in TL on subjective well-being.
Watson et al., [46]	To determine whether acute TL and sleep are independent predictors of subjective well-being and whether sleep mediates the influence of acute TL on subjective well-being in female youth athletes.	Average sleep duration was 7.9 ± 1.4 h during the study period. Sleep duration mediated a significant portion of the effect of TL on mood (26.8%, p < 0.001), fatigue (12.6%, p < 0.001), and stress (24.5%, p < 0.001).	Increased sleep was significantly associated with improved fatigue, mood, and stress. In fact, a significant portion of the effect of TL on subjective well-being was because of TL on sleep.
Wilson et al., [47]	To establish how the timing of sleep was influenced by fasting diurnal requirements and how training practices were altered in professional soccer players by comparing behavior over the RF month to that displayed in the four weeks immediately following.	The TL, as indicated by training impulse scores, did not vary between RF and the following four weeks, although the duration of training sessions was shortened after two weeks of RF. Duration of sleep was prolonged during RF by 99 min on average.	A significant change in the timing of sleep was the main way that a group of professional soccer players adjusted to cope with the RF. Thus, influence of RF on daily activities is more a matter of chronobiology than calorie restriction.

RPE: rated perceived exertion; s-RPE: session rated perceived exertion; HR: heart rate; TL: training load; RF: Ramadan Fasting; SSGs: small-sided games.