Momoko Kayaba

Exercise Increases 24-h Fat Oxidation Only When It Is Performed Before Breakfast.

Background As part of the growing lifestyle diversity in modern society, there is wide variation in the time of day individuals choose to exercise. Recent surveys in the US and Japan have reported that on weekdays, more people exercise in the evening, with fewer individuals exercising in the morning or afternoon. Exercise performed in the post-prandial state has little effect on accumulated fat oxidation over 24 h (24-h fat oxidation) when energy intake is matched to energy expenditure (energy-balanced condition). The present study explored the possibility that exercise increases 24-h fat oxidation only when performed in a post-absorptive state, i.e. before breakfast. Methods Indirect calorimetry using a metabolic chamber was performed in 10 young, non-obese men over 24 h. Subjects remained sedentary (control) or performed 60-min exercise before breakfast (morning), after lunch (afternoon), or after dinner (evening) at 50% of VO2max. All trials were designed to be energy balanced over 24 h. Time course of energy and substrate balance relative to the start of calorimetry were estimated from the differences between input (meal consumption) and output (oxidation). Findings Fat oxidation over 24 h was increased only when exercise was performed before breakfast (control, 456 ± 61; morning, 717 ± 64; afternoon, 446 ± 57; and evening, 432 ± 44 kcal/day). Fat oxidation over 24 h was negatively correlated with the magnitude of the transient deficit in energy and carbohydrate. Interpretation Under energy-balanced conditions, 24-h fat oxidation was increased by exercise only when performed before breakfast. Transient carbohydrate deficits, i.e., glycogen depletion, observed after morning exercise may have contributed to increased 24-h fat oxidation.

Association between sleep and residential environments in the summertime in Japan

OBJECTIVES We aimed to identify the effect of environmental factors on sleep in the summertime in Japan. METHODS A self-reported questionnaire survey was conducted in Japan. Age of participants ranged from 20 to 70 years. RESULTS The mean Pittsburgh Sleep Quality Index (PSQI) score was 4.9 (±2.7), and 123 (35.0%) participants had scores of >5. According to the results of multivariate logistic regression analysis, the adjusted odds ratio (aOR) for PSQI scores of >5 without installation of air conditioner was 1.8 (95% confidence interval [CI], 1.0-3.3; P<.05), use of a light bulb was 3.7 (95% CI, 1.1-12.6; P<.05), and noise was 2.1 (95% CI, 1.1-4.1; P<.05) after controlling for several confounding variables. Difficulty initiating sleep (DIS) was associated with installation of an air conditioner (1 [reference] to 3 [aOR, 2.5 {95% CI, 1.2-5.1}] and 4 [aOR, 2.8 {95% CI, 1.1-7.1}]) and noise (1 [reference] to 3 [aOR, 2.4 {95% CI, 1.0-5.9}] and 4 [aOR, 8.8 {95% CI, 3.1-25.0}]). Difficulty maintaining sleep (DMS) was associated with installation of a fan (1 [reference] to 2 [aOR, 0.4 {95% CI, 0.2-0.8}] and noise (1 [reference] to 3 [aOR, 2.3 {95% CI, 1.0-5.3}]) after controlling for several confounding variables. CONCLUSIONS Our finding using analysis of the association between residential environments and subjective sleep statuses, which determined that the installation of an air conditioner and lighting equipment might affect sleep, may be useful to discuss sleep environments and improve sleep quality.

Erratum to: The effect of nocturnal blue light exposure from light-emitting diodes on wakefulness and energy metabolism the following morning.

Sleep TIB, min 480.0 480.0 TST, min 448.1 ± 3.3 452.9 ± 3.6 NS SE, % 93.4 ± 0.7 94.5 ± 0.8 NS Stage 1, min 49.4 ± 6.0 41.6 ± 4.8 NS Stage 2, min 248.9 ± 12.1 250.7 ± 14.7 NS SWS, min 54.2 ± 8.0 59.6 ± 7.8 NS REM, min 96.9 ± 13.4 103.2 ± 12.8 NS NREM, min 351.2 ± 13.8 349.7 ± 12.9 NS WASO, min 21.1 ± 2.4 18.2 ± 3.2 NS SL, min 8.6 ± 2.8 5.9 ± 1.4 NS RL, min 96.1 ± 12.1 108.2 ± 19.2 NS In the following morning Stage 1 and 2, min 26.0 ± 9.8 6.3 ± 2.7 \0.05

Energy metabolism differs between sleep stages and begins to increase prior to awakening

PURPOSE Human sleep is generally consolidated into a single prolonged period, and its metabolic consequence is to impose an extended period of fasting. Changes in sleep stage and homeostatic sleep drive following sleep onset may affect sleeping metabolic rate through cross talk between the mechanisms controlling energy metabolism and sleep. The purpose of this study was to isolate the effects of sleep stage and time after sleep onset on sleeping metabolic rate. METHODS The sleeping metabolic rate of 29 healthy adults was measured using whole room indirect calorimetry, during which polysomnographic recording of sleep was performed. The effects of sleep stage and time after sleep onset on sleeping metabolic rate were evaluated using a semi-parametric regression analysis. A parametric analysis was used for the effect of sleep stage and a non-parametric analysis was used for the effect of time. RESULTS Energy expenditure differed significantly between sleep stages: wake after sleep onset (WASO)>stage 2, slow wave sleep (SWS), and REM; stage 1>stage 2 and SWS; and REM>SWS. Similarly, carbohydrate oxidation differed significantly between sleep stages: WASO > stage 2 and SWS; and stage 1>SWS. Energy expenditure and carbohydrate oxidation decreased during the first half of sleep followed by an increase during the second half of sleep. CONCLUSIONS This study identified characteristic phenotypes in energy expenditure and carbohydrate oxidation indicating that sleeping metabolic rate differs between sleep stages.

Effects of subacute ingestion of chlorogenic acids on sleep architecture and energy metabolism through activity of the autonomic nervous system: a randomised, placebo-controlled, double-blinded cross over trial

Chlorogenic acids (CGA) are the most abundant polyphenols in coffee. Continuous consumption of CGA reduces body fat and body weight. Since energy metabolism and sleep are controlled by common regulatory factors, consumption of CGA might modulate sleep. Lack of sleep has been identified as a risk factor for obesity, hypertension and type 2 diabetes. The aim of this study was to determine the effects of ingesting CGA over 5 d on energy metabolism and sleep quality in humans. A total of nine healthy subjects (four male and five female) completed a placebo-controlled, double-blinded, cross-over intervention study. Subjects consumed a test beverage containing 0 or 600 mg of CGA for 5 d. On the fifth night, subjects stayed in a whole-room metabolic chamber to measure energy metabolism; sleep was evaluated using polysomnographic recording. It was found that CGA shortened sleep latency (9 (sem 2) v. 16 (sem 4) min, P<0·05) compared with the control, whereas no effect on sleep architecture, such as slow-wave sleep, rapid eye movement or waking after sleep onset, was observed. Indirect calorimetry revealed that consumption of CGA increased fat oxidation (510 (sem 84) kJ/8 h (122 (sem 20) kcal/8 h) v. 331 (sem 79) kJ/8 h (81 (sem 19) kcal/8 h), P<0·05) but did not affect energy expenditure during sleep. Consumption of CGA enhanced parasympathetic activity assessed from heart-rate variability during sleep (999 (sem 77) v. 919 (sem 54), P<0·05). A period of 5-d CGA consumption significantly increased fat oxidation during sleep, suggesting that beverages containing CGA may be beneficial to reduce body fat and prevent obesity. Consumption of CGA shortened sleep latency and did not adversely affect sleep quality.

Exercise before breakfast increases 24-h fat oxidation in female subjects

Background Exercise performed in a postprandial state does not increase 24-h fat oxidation of male and female subjects. Conversely, it has been shown in male subjects that exercise performed in a postabsorptive state increases 24-h fat oxidation compared with that in sedentary control and that with exercise trials performed after breakfast, lunch, or dinner. There is a paucity of study evaluating the effect of exercise performed in a postabsorptive state in female subjects. Method Nine young female subjects participated in indirect calorimetry measurement over 24-h using a room-size metabolic chamber in which subjects remained sedentary or performed 60 min exercise before breakfast at 50% of V˙O2max. Exercise was accompanied by an increase in energy intake to ensure that subjects were in a similar state of energy balance over 24 h for the two trials. Findings Compared with the sedentary condition, exercise performed before breakfast increased 24-h fat oxidation (519 ± 37 vs. 400 ± 41 kcal/day). Time courses of relative energy balance differed between trials with transient negative energy balance observed before breakfast. The lowest values of relative energy balance observed during the 24-h calorimetry, i.e., transient energy deficit, were greater in exercise trials than in sedentary trials. The transient deficit in carbohydrate balance was also observed before breakfast, and magnitude of the deficit was greater in exercise trial compared to that of sedentary trial. Interpretation Under energy-balanced conditions, exercise performed in a post-absorptive state increases 24-h fat oxidation in female subjects. The effect of exercise performed before breakfast can be attributed to nutritional state: a transient deficit in energy and carbohydrate at the end of exercise.