Associations of Anxiety, Insomnia, and Physical Activity during the COVID-19 Pandemic.

PURPOSE: Anxiety, insomnia, and physical activity (PA) are interrelated, but the bi-directional relationships between these three variables are not well understood. Less is known of these relationships in settings of disrupted daily activities and acute stress. This study aimed to characterize and examine relationships between insomnia, anxiety, and PA throughout the first year of the COVID-19 pandemic, when many lifestyle behaviors were disrupted. METHODS: Participants comprised a convenience sample of 204 adults (55.4% female; 43.85 ± 15.85 years old) who completed the Generalized Anxiety Disorder Questionnaire (GAD-7), Insomnia Severity Index (ISI), and the International Physical Activity Questionnaire (IPAQ) at three time points through the first year of the COVID-19 pandemic. A cross-lagged panel model was used to evaluate these variables' concurrent, autoregressive, and cross-lagged relationships across time. Follow-up dynamic panel modeling using maximum likelihood and structural equation modeling was employed. RESULTS: Approximately 64% of participants reported their work/occupation as affected by the pandemic. At baseline, associations between anxiety and insomnia were observed (ß-coefficient: 15.87; p < 0.001). Insomnia was a positive future predictor of anxiety (ISI time point 2: 7.9 ± 5.6 points; GAD-7 at time point 3: 4.1 ± 4.2 points; ß-coefficient: 0.16; p < 0.01). No associations were observed between PA and anxiety or insomnia (all p > 0.05). CONCLUSIONS: Insomnia and anxiety were interrelated, and effects were cross-lagged. These data can inform future work focused on improving anxiety in settings of acute stress and disruptions to daily life, such as changes in occupational structure and stability. Specifically, targeting sleep parameters may be of interest to elicit downstream positive health behaviors.

Finding balance: understanding the energetics of time-restricted feeding in mice.

Over the course of mammalian evolution, the ability to store energy likely conferred a survival advantage when food became scarce. A long-term increase in energy storage results from an imbalance between energy intake and energy expenditure, two tightly regulated parameters that generally balance out to maintain a fairly stable body weight. Understanding the molecular determinants of this feat likely holds the key to new therapeutic development to manage obesity and associated metabolic dysfunctions. Time-restricted feeding (TRF), a dietary intervention that limits feeding to the active phase, can prevent and treat obesity and metabolic dysfunction in rodents fed a high-fat diet, likely by exerting effects on energetic balance. Even when body weight is lower in mice on active-phase TRF, food intake is generally isocaloric as compared with ad libitum fed controls. This discrepancy between body weight and energy intake led to the hypothesis that energy expenditure is increased during TRF. However, at present, there is no consensus in the literature as to how TRF affects energy expenditure and energy balance as a whole, and the mechanisms behind metabolic adaptation under TRF are unknown. This review examines our current understanding of energy balance on TRF in rodents and provides a framework for future studies to evaluate the energetics of TRF and its molecular determinants.

The Effects of an Acute Bout of Aerobic or Resistance Exercise on Nonexercise Physical Activity.

Introduction/Purpose: A reduction in nonexercise physical activity (NEPA) after exercise may reduce the effectiveness of exercise interventions on weight loss in adults with overweight or obesity. Aerobic exercise (AEx) and resistance exercise (REx) may have different effects on NEPA. The purpose of this secondary analysis was to examine the effect of a single bout of AEx or REx on NEPA and sedentary behavior in inactive adults with overweight or obesity. Methods: Adults with overweight or obesity (n = 24; 50% male; age, 34.5 ± 1.5 yr; body mass index, 28.5 ± 0.9 kg·m-2) not meeting current physical activity guidelines completed a single 45-min bout of AEx, REx, or a sedentary control on different days in random order. After each condition, participants' NEPA was recorded for 84 h by accelerometer. Time spent sedentary and in light, moderate, and vigorous physical activity; steps; metabolic equivalent of task (MET)-hours; and sit-to-stand transitions were calculated using activity count data. Results: No differences were observed in the percent of waking time spent sedentary and in light, moderate, and vigorous activity between conditions (P > 0.05). No differences were observed in steps, MET-hours, or sit-to-stand transitions between conditions (P > 0.05). NEPA responses were variable among individuals, with approximately half of participants reducing and half increasing NEPA over the 84 h after each exercise condition. Conclusion: NEPA was not reduced after an acute bout of AEx or REx in a sample of inactive adults with overweight or obesity.

Challenges and Opportunities for Applying Wearable Technology to Sleep.

Wearable technology has a history in sleep research dating back to the 1970s. Because modern wearable technology is relatively cheap and widely used by the general population, this represents an opportunity to leverage wearable devices to advance sleep medicine and research. However, there is a lack of published validation studies designed to quantify device performance against accepted gold standards, especially across different populations. Recommendations for conducting performance assessments and using wearable devices are now published with the goal of standardizing wearable device implementation and advancing the field.

The effects of acute exercise on appetite and energy intake in men and women.

PURPOSE: To compare energy intake (EI) and appetite regulation responses between men and women following acute bouts of aerobic (AEx), resistance exercise (REx), and a sedentary control (CON). METHODS: Men and women (n = 24; 50% male) with overweight/obesity, matched on age (32.3 ±â€¯2 vs. 36.8 ±â€¯2 yrs, p = 0.14) and BMI (28.1 ±â€¯1.2 vs 29.0 ±â€¯1.5 kg/m2, p = 0.64) completed 3 conditions: 1) AEx (65-70% of age-predicted maximum heart rate for 45 min); 2) REx (1-set to failure on 12 exercises); and 3) CON. Each condition was initiated in the post-prandial state (35 min following consumption of a standardized breakfast). Appetite (visual analog scale for hunger, satiety, and prospective food consumption [PFC]) and hormones (ghrelin, PYY, and GLP-1) were measured in the fasted state and every 30 min post-prandially for 3 h. Post-exercise ad libitum EI at the lunch meal was also measured. RESULTS: Men reported higher levels of hunger compared to women across all study conditions (AEx: Men: 7815.00 ±â€¯368.3; Women: 5428.50 ±â€¯440.0 mm x 180 min; p = 0.025; REx: Men: 7110.00 ±â€¯548.4; Women: 6086.25 ±â€¯482.9 mm x 180 min; p = 0.427; CON: Men: 8315.00 ±â€¯429.8; Women: 5311.25 ±â€¯543.1 mm x 180 min; p = 0.021) and consumed a greater absolute caloric load than women at the ad libitum lunch meal (AEx: Men: 1021.6 ±â€¯105.4; Women: 851.7 ±â€¯70.5 kcals; p = 0.20; REx: Men: 1114.7 ±â€¯104.0; Women: 867.7 ±â€¯76.4 kcals; p = 0.07; CON: Men: 1087.0 ±â€¯98.8; Women: 800.5 ±â€¯102.3 kcals; p = 0.06). However, when adjusted for relative energy needs, there was no difference in relative ad libitum EI observed between men and women. No differences in Area Under the Curve for Satiety, PFC, ghrelin, PYY, and GLP-1 were noted between men and women following acute exercise (all p > 0.05). CONCLUSIONS: These data suggest that women report lower ratings of appetite following an acute bout of exercise or sedentary time when compared to men, yet have similar relative EI. Future work is needed to examine whether sex-based differences in appetite regulation and EI are present with chronic exercise of differing modalities.