Limited observational studies have described the relationship between sleep duration and overall diet. The present study investigated the association between sleep duration on weekdays or social jetlag and empirically derived dietary patterns in a nationally representative sample of UK adults, aged 19–64 years old, participating in the 2008–2012 UK National Diet and Nutrition Survey Rolling Programme. Survey members completed between three to four days of dietary records. Sleep duration on weekdays was categorized into tertiles to reflect short, normal, and long sleep duration. Social jetlag was calculated as the difference between sleep duration on weekends and weekdays. The association between sleep duration/social jetlag and dietary patterns, derived by principal components analysis, was assessed by regressing diet on sleep, whilst accounting for the complex survey design and adjusting for relevant confounders. Survey members in the highest tertile of sleep duration had on average a 0.45 (95% Confidence Interval (CI) −0.78, −0.12) lower healthy dietary pattern score, compared to middle tertile (p = 0.007). There was an inverted u-shaped association between social jetlag and the healthy dietary pattern, such that when sleep on weekends exceeded weekday sleep by 1 h 45 min, scores for indicating a healthy dietary pattern declined (p = 0.005). In conclusion, long sleep duration on weekdays and an increased social jetlag are associated with a lower healthy dietary pattern score. Further research is required to address factors influencing dietary patterns in long sleepers.

Walsh, JA, Sanders, D, Hamilton, DL, and Walshe, I. Sleep profiles of elite swimmers during different training phases. J Strength Cond Res 33(3): 811–818, 2019—This study aims to describe the sleeping patterns during different training phases in competitive swimmers. Twelve national- and international-level swimmers (3 females and 9 males) were monitored during 4 different phases, consisting of a preparation training phase, a taper phase, a competition phase, and a rest phase. Sleep parameters were assessed using wrist activity monitors and self-reported sleep diaries. There was a moderately higher (d = 0.70–1.00) sleep onset latency during the competition phase compared with taper, train, and rest phases. Trivial to small differences were observed for total sleep time between phases (d = 0.05–0.40). Sleep efficiency was moderately higher (d = 0.60–0.75) in the training and taper phases compared with competition and rest. Restfulness and fragmentation index (FI) were lowest in the rest with differences between phases being small (d = 0.43–0.51) for restfulness and small to moderate (d = 0.43–0.62) for FI. Time in and out of bed was very largely later (d = 1.96–2.34) in rest compared with the other phases. Total nap time was moderately lower in rest (d = 1.13–1.18) compared with the training and competition phases, whereas there was a small difference (d = 0.46) compared with taper. To conclude, while there were trivial to small differences in sleep quantity between phases, there are small to moderate differences in other sleep parameters. Specifically, sleep onset latency was higher during the competition phase. In addition, this study highlights the substantial between-individual variations in sleep responses during different training phases.

Tart cherry (TC) consumption has become a popular nutritional strategy for recovery, particularly for the attenuation of markers associated with muscle damage. However, there are relatively few studies that have examined an acute dosing strategy. The aim of this pilot study was to explore the feasibility of using powdered Vistula TC for recovery following a bout of muscle-damaging exercise. Twenty-two recreationally active participants (mean ± SD age, stature, and mass were 23 ± 3 years old, 173 ± 10 cm, and 74 ± 17 kg, respectively) performed 40 (5 sets of 8 repetitions) maximal lengthening contractions of the elbow flexors. The participants were randomised to receive either a spray-dried TC extract or a calorie-matched placebo (12 TC, 10 placebo) for 4 days in total, starting on the day of exercise. Dependent measures of maximal voluntary contraction (MVC), muscle soreness (assessed via visual analogue scales; VAS), pain pressure threshold (PPT), range of motion (ROM), and upper arm limb girth were taken at baseline (pre), 24, 48, and 72 h post damaging exercise. There were significant changes over time among all the variables (MVC, VAS, PPT, ROM, and girth, p ≤ 0.014). There were no significant differences between the conditions for any of the variables (MVC, VAS, PPT, ROM, and girth, p > 0.3). The TC group did not recover at an accelerated rate compared to the placebo. This study provides initial insights into the use of powdered Vistula TC and its effect following strenuous (damaging) exercise bouts. Vistula TC did not improve recovery when taken acutely following a bout of damaging exercise to the elbow flexors.

Evidence suggests reduced glycaemic control following sleep restriction in healthy individuals. However, it remains unknown if impairments in glycaemic control increase with each additional night of sleep restriction in a linear manner. This randomised crossover study aimed to determine if the impairment in glycaemic control increases with each additional night of sleep restriction. Ten healthy individuals underwent 4 nights of control sleep (8 hours in bed) and 4 nights of sleep restriction (4 hours in bed) in a sleep laboratory. An oral glucose tolerance test was conducted each morning. Serum glucose and insulin were measured. Glucose and insulin area under the curve were higher overall in the sleep restriction trial compared with control (p < 0.001 and p = 0.033); however, no effect of day (p = 0.620 and p = 0.863) or interaction effect (p = 0.152 and p = 0.285) were observed. This supports previous literature showing a detrimental impact of sleep restriction on glucose regulation. The present findings, however, suggest the impairment in glycaemic control does not increase in a linear manner with an increasing number of nights of sleep restriction. This may have implications for the design of future studies examining sleep restriction and glycaemic control. Novelty: Four nights of sleep restriction impaired glycaemic control in healthy individuals, but did not do so in a linear manner. No effect of number of nights of restriction was found for glucose or insulin, which may have implications for future studies.

Limited observational studies have described the relationship between sleep duration and overall diet. The present study investigated the association between sleep duration at weekdays and empirically derived dietary patterns in a nationally representative sample of UK adults, aged 19-64 years old, participating in the 2008-2012 UK National Diet and Nutrition Survey Rolling Programme. Survey members completed between three to four days of dietary records. Sleep duration at weekdays was categorised into tertiles to reflect short, normal and long sleep duration. Social jetlag was calculated as the difference between sleep duration at weekends and weekdays. The association between sleep duration/ social jetlag and dietary patterns, derived by principal components analysis, was assessed regressing diet on sleep whilst accounting for the complex survey design and adjusting for relevant confounders. Survey members in the highest tertile of sleep duration had on average 0.45 (95% CI -0.78, -0.12) lower healthy dietary pattern score compared to middle tertile (p =0.007). There was an inverted u-shaped association between social jetlag and a healthy dietary pattern, such that when sleep at weekends exceeded weekday sleep by 1h 45min, scores for indicating a healthy dietary pattern declined (p =0.005). In conclusion, long sleep duration at weekdays and an increased social jetlag are associated with a lower healthy dietary pattern score. Further research is required to address factors influencing dietary patterns in long sleepers.

Purpose: Long-distance running induces marked increases in inflammation and muscle damage. Tart cherries (TC) have become a popular nutritional strategy for exercise recovery, particularly for attenuation of markers associated with muscle damage and inflammation. Research question. The aim of this study was to examine the effect of a yet-to-be-explored cultivar (Vistula) of TC on recovery following a marathon. Methods: Thirty-five recreationally trained marathon runners (mean ± SD age, stature, and mass were 40 ± 10 years old, 176.5 ± 10.2 cm, and 78.8 ± 13.8 kg, respectively) completed an undulating marathon course. Participants were randomised to receive either freeze-dried TC powder or calorie-matched placebo (17 TC, 18 placebo) for 7 days, with the marathon on day 5 of supplementation. Maximal voluntary contractions (MVC), counter movement jumps (CMJ), muscle soreness (DOMS), plasma creatine kinase (CK), and high-sensitive C-reactive protein (hs-CRP) were assessed before, immediately after, and at 24- and 48-h post marathon. Results: There were significant changes over time for all variables ( p < 0.001) indicating muscle damage. There were no treatment or interaction effects for MVC, CMJ, DOMS, and CK ( p > 0.2). However, there was a treatment effect for hs-CRP, where the TC group experienced lower levels of hs-CRP (mean ± SD during recovery: TC 7.9 ± 3.5, placebo 12.5 ± 5.1 mg/L, p = 0.031). Conclusions: The marathon caused changes in muscle damage and inflammation indices. Despite no functional or soreness differences, the TC group showed lower inflammation levels, offering insights into Vistula tart cherries for recovery.