It is unclear how timing of exercise relative to meal ingestion influences substrate balance and metabolic responses. The present study aimed to compare the effects of exercise performed before or after breakfast on fat balance and postprandial metabolism. A total of ten sedentary overweight men (aged 28·1 (SEM 10·7) years, BMI 29·0 (SEM 2·8) kg/m 2 ) underwent three trials in random order involving: (1) performing no exercise (CON), or walking for 60 min at 50 % maximal O 2 uptake either (2) before (Ex-Meal) or (3) after (Meal-Ex) consuming a standardised breakfast meal. In each trial an ad libitum lunch was provided 3·5 h after breakfast. Substrate utilisation was assessed by indirect calorimetry and blood was taken at regular intervals over an 8·5 h observation period. At the end of the observation period, fat balances in the Ex-Meal (21043 (SEM 270) kJ) and Meal-Ex (2697 (SEM 201) kJ) trials were both significantly lower than CON (204 (SEM 165) kJ) and fat balance in the Ex-Meal trial was significantly lower than in the Meal-Ex trial (all P , 0·0001). Compared with the CON trial, the 8·5 h postprandial TAG response was only significantly lowered in the Ex-Meal trial (217 %, P ¼ 0·025) and not in the Meal-Ex trial (211 %, P ¼ 0·20). Both the Ex-Meal and Meal-Ex trials showed significantly lowered insulin responses relative to the CON trial (by 19 and 24 %, respectively, P , 0·01 for both). There were no differences in lunch energy intake between trials. The present findings suggest that there may be an advantage for body fat regulation and lipid metabolism in exercising before compared with after breakfast. However, further study is needed to determine whether the present findings extend over the long term under free-living conditions. Key words: Exercise: Postprandial metabolism: Fat balance: Appetite: Energy balance: Ad libitum energy intake Loss of body fat requires the imposition of a negative fat balance, which is achieved when fat oxidation exceeds fat intake (1) . Exercise provides a potent means of increasing fat oxidation, both during the exercise itself and in the hours afterwards (2) , and thus can potentially contribute to the formation of a negative fat balance. However, as exercise can also influence food intake (3) and the metabolism of ingested food (4,5) , it is necessary to also consider the interactions between exercise and food intake to fully evaluate the overall effects of exercise on fat balance. It is well-known that consuming a meal prior to exercise reduces fat, and increases carbohydrate oxidation during the exercise period (6,7) , whereas a post-exercise meal can attenuate the shift from carbohydrate to fat oxidation that normally follows exercise (8) . Thus, the timing of exercise relative to meal ingestion influences the pattern, and potentially the extent, of the exerciseinduced increase in fat oxidation. Studies comparing the effects of exercise before or after a single meal have reported greater total fat oxidation over observation periods of 2 -8 h when exercise was u...

(1) Background: The Pittsburgh Sleep Quality Index (PSQI) is a useful tool for the assessment of subjective sleep quality in non-clinical and clinical settings. This study aimed to determine sleep quality in a general Malaysian adult population using a validated Malay version of the Pittsburgh sleep quality index (PSQI-M); (2) Methods: The original PSQI was translated into Malay following forward and backward translation guidelines. The final Malay version was administered to a sample of healthy working adults (n = 106; mean age: 35.3 ± 7.6 years) without history of sleep disorders. Reliability and agreement were assessed using Cronbach’s alpha, intra-class correlations coefficient (ICC), standard error of measurement (SEM), and Bland–Altman plot. Convergent validity of PSQI-M was examined with the Malay version of Epworth sleepiness scale (ESS-M) using Pearson’s correlation coefficient; (3) Results: Overall mean PSQI global score was 5.25 ± 1.85. About 45% of the sample had PSQI global score >5, indicating poor sleep quality. Total sleep duration per night was 5.95 ± 1.05 h, below the recommended amount. Sleep quality seems to be affected by age but not gender. Internal consistency as measured by Cronbach’s alpha in the whole sample was 0.74, with test–retest reliability (ICC) of 0.58 and SEM of 1.34. The PSQI test–retest scores indicated that most of the respondents (90%) lay within the 95% limits of agreement. The PSQI-M also showed significant correlation with ESS-M scores (r = 0.37, p < 0.01); (4) Conclusion: The PSQI-M showed acceptable reliability and is valid to be used in a general Malaysian adult population. Findings also indicate that a majority of the adults in our sample were experiencing inadequate sleep, thus further research is needed to identify the factors associated with poor sleep quality.

Previous exercise attenuates the lipemic response to ad libitum meals, suggesting that exercise's TG-lowering effect will extend into "real-world" settings where food intake is not carefully controlled. This response is not augmented by exercising on repeated days.

Background: The effect of circadian disruption on the bio-psychological clock system has been widely studied. However, the mechanism and the association of circadian rhythm disruption with mental health and physiological responses are still unclear. Therefore, this study was conducted to investigate the effects of circadian rhythm disruption on mental health and physiological responses among shift workers and the general population. Methods: A total of 42 subjects participated in this quasi-experimental study. Participants were divided into a group of shift workers (n = 20) and a general population group (n = 22). Polysomnography tests, blood tests (cortisol, triglycerides and glucose), and psychological tests (Abbreviated Profile of Mood States, General Health Questionnaire-28, Working Memory and Processing Speed Indexes of the Wechsler Adult Intelligent Scale (WAIS-IV) were used to examine the effects of circadian rhythm disruption. Results: The results showed a significant relationship between circadian rhythm disruption and mood (r = 0.305, p < 0.05). The findings of this study also indicated that there was a significant effect of circadian rhythm disruption on mood (F(2,40) = 8.89, p < 0.001, η2 =0.182), processing speed (F(2,40) = 9.17, p < 0.001, η2 = 0.186) and working memory (F(2,40) = 4.963, p < 0.01, η2 = 0.11) in shift workers and the general population. Conclusions: Our findings showed that circadian rhythm disruption affects mood and cognitive performance, but it does not significantly affect psychological wellbeing and physiological responses. Future studies are warranted to examine moderator and mediator variables that could influence the circadian rhythm disruption.