Exercise in a natural environment increases program compliance in people with chronic migraine: A pilot cross-over randomized trial.

Adverse side effects from pharmacological treatments cause people with migraine to delay or avoid taking medication. Exercise is effective, but the effect of environment is unknown. The purpose was to determine if a natural environment affects monthly migraine load. Sedentary individuals (8 female, 1 non-binary) who experienced migraines participated. Participants completed one month of exercise (3 x week, 30-min, 60-70% estimated HRmax) indoors as well as in a natural outdoor environment in a randomized counterbalanced order. Migraine load was determined using the Headache Impact Test (HIT-6) and Migraine Disability Assessment (MIDAS) at the beginning and end of each month. Data were analyzed using repeated measures ANOVA. No interactions were evident for HIT-6 (p = 0.80), MIDAS (p = 0.72), migraine days (p = 0.508), or pain intensity (p = 0.66). No main effects were noted. Compliance was greater in the outdoor environment, with more exercise sessions completed in nature (Indoor = 72%, Outdoor = 90%, p < 0.001). Exercise environment did not impact MIDAS or HIT-6 questionnaire results, number of migraine days, or pain intensity. While there was no reduction in migraine load, it is possible that other health benefits were experienced due to greater compliance in a natural environment.

Social jet lag impairs exercise volume and attenuates physiological and metabolic adaptations to voluntary exercise training.

Social jet lag (SJL) is a misalignment between sleep and wake times on workdays and free days. SJL leads to chronic circadian rhythm disruption and may affect nearly 70% of the general population, leading to increased risk for cardiometabolic diseases. This study investigated the effects of SJL on metabolic health, exercise performance, and exercise-induced skeletal muscle adaptations in mice. Ten-week-old C57BL/6J mice (n = 40) were allocated to four groups: control sedentary (CON-SED), control exercise (CON-EX), social jet lag sedentary (SJL-SED), and social jet lag exercise (SJL-EX). CON mice were housed under a 12:12-h light-dark cycle. SJL was simulated by implementing a 4-h phase delay for 3 days to simulate "weekends," followed by a 4-h phase advance back to "weekdays," for 6 wk. EX mice had free access to a running wheel. Graded exercise tests (GXTs) and glucose tolerance tests (GTTs) were performed at baseline and after intervention to monitor the effects of exercise and social jet lag on cardiorespiratory and metabolic health, respectively. SJL led to alterations in activity and running patterns and clock gene expression in skeletal muscle and decreased average running distance (P < 0.05). SJL-SED mice gained significantly more weight compared with CON-SED and SJL-EX mice (P < 0.01). SJL impaired fasting blood glucose and glucose tolerance compared with CON mice (P < 0.05), which was partially restored by exercise in SJL-EX mice. SJL also blunted improvements in exercise performance and mitochondrial content in the quadriceps. These data suggest that SJL blunted some cardiometabolic adaptations to exercise and that proper circadian hygiene is necessary for maintaining health and performance.NEW & NOTEWORTHY In mice, disrupting circadian rhythms with social jet lag for 6 wk caused significant weight gain, higher fasting blood glucose, and impaired glucose tolerance compared with control. Voluntary exercise in mice experiencing social jet lag prevented weight gain, though the mice still experienced increased fasting blood glucose and impaired exercise performance compared with trained mice not experiencing social jet lag. Social jet lag seems to be a potent circadian rhythm disruptor that impacts exercise-induced training adaptations.

Effects of Acute Sleep Deprivation on the Physiological Response to Woodsmoke and Exercise.

OBJECTIVE: To evaluate sleep deprivation effects on the acute physiological response to a combined stressor of woodsmoke and exercise. METHODS: Ten participants completed two exercise trials (8 hours of sleep vs 4 hours) with woodsmoke. Trials were conducted in a crossover design. Key measures examined before and after each trial included heart rate variability, pulse wave velocity, blood pressure, pulmonary function testing, and oxidative stress. RESULTS: Acute sleep deprivation experienced before exercise and woodsmoke exposure did not impact metrics of heart rate variability, pulse wave velocity, pulmonary function testing, blood pressure, or oxidative stress. CONCLUSIONS: Acute sleep deprivation did not amplify physiologic metrics in response to moderate-intensity aerobic exercise with inhaled woodsmoke. Although findings do not eliminate the negative impacts of inhaling woodsmoke, more research is needed to understand the acute effects of woodsmoke exposure on the cardiovascular system. 1.

Effects of time-restricted exercise on activity rhythms and exercise-induced adaptations in the heart.

Circadian rhythms play a crucial role in the regulation of various physiological processes, including cardiovascular function and metabolism. Exercise provokes numerous beneficial adaptations in heart, including physiological hypertrophy, and serves to shift circadian rhythms. This study investigated the impact of time-restricted exercise training on exercise-induced adaptations in the heart and locomotor activity rhythms. Male mice (n = 45) were allocated to perform voluntary, time-restricted exercise in the early active phase (EAP), late active phase (LAP), or remain sedentary (SED) for 6 weeks. Subsequently, mice were allowed 24-h ad libitum access to the running wheel to assess diurnal rhythms in locomotor activity. Heart weight and cross-sectional area were measured at sacrifice, and cardiac protein and gene expression levels were assessed for markers of mitochondrial abundance and circadian clock gene expression. Mice rapidly adapted to wheel running, with EAP mice exhibiting a significantly greater running distance compared to LAP mice. Time-restricted exercise induced a shift in voluntary wheel activity during the 24-h free access period, with the acrophase in activity being significantly earlier in EAP mice compared to LAP mice. Gene expression analysis revealed a higher expression of Per1 in LAP mice. EAP exercise elicited greater cardiac hypertrophy compared to LAP exercise. These findings suggest that the timing of exercise affects myocardial adaptations, with exercise in the early active phase inducing hypertrophy in the heart. Understanding the time-of-day dependent response to exercise in the heart may have implications for optimizing exercise interventions for cardiovascular health.

Heart rate processing algorithms and exercise duration on reliability and validity decisions in biceps-worn Polar Verity Sense and OH1 wearables.

Consumer wearable technology use is widespread and there is a need to validate measures obtained in uncontrolled settings. Because no standard exists for the treatment of heart rate data during exercise, the effect of different approaches on reliability (Coefficient of Variation [CV], Intraclass Correlation Coefficient [ICC]) and validity (Mean Absolute Percent Error [MAPE], Lin's Concordance Correlation Coefficient [CCC)] were determined in the Polar Verity Sense and OH1 during trail running. The Verity Sense met the reliability (CV < 5%, ICC > 0.7) and validity thresholds (MAPE < 5%, CCC > 0.9) in all cases. The OH1 met reliability thresholds in all cases except entire session average (ICC = 0.57). The OH1 met the validity MAPE threshold in all cases (3.3-4.1%), but not CCC (0.6-0.86). Despite various heart rate data processing methods, the approach may not affect reliability and validity interpretation provided adequate data points are obtained. It is also possible that a large volume of data will artificially inflate metrics.

Time of Day and Chronotype-Dependent Synchrony Effects Exercise-Induced Reduction in Migraine Load: A Pilot Cross-Over Randomized Trial.

Migraines are the most common cause of chronic pain. Effective, non-pharmacological strategies to reduce migraine load, like exercise, are needed, but it is unclear how exercise timing and chronotype modulate the effects. We sought to determine the effects of time-of-day of exercise, and synchrony with one's chronotype, on migraine load. We performed a pilot cross-over randomized trial where participants with chronic migraine completed two one-month exercise interventions, consisting of either morning exercise (before 09:00 a.m.) or evening exercise (after 7:00 p.m.) in a randomized repeated measures cross-over design (Clinical Trial #NCT04553445). Synchrony was determined by exercise time and chronotype (i.e., a morning type participant exercising in the morning is 'in-sync,' while an evening type participant exercising in the morning is 'out-of-sync'). Migraine burden, and anthropometric assessment occurred before and after each month of exercise. Data was analyzed using repeated measures ANOVA with significance accepted at p < 0.05. When comparing morning and evening exercise, there was no significant improvements in any migraine-related parameters. However, when comparing in-sync and out-of-sync exercise, we found that migraine burden was only improved following in-sync exercise, while no benefits were seen in out-of-sync exercise. Our data suggests that exercise timing has limited impact, but synchrony with chronotype may be essential to decrease migraine load in chronic migraineurs.

Circadian acclimatization of performance, sleep, and 6-sulfatoxymelatonin using multiple phase shifting stimuli.

Misalignment between the environment and one's circadian system is a common phenomenon (e.g., jet lag) which can have myriad negative effects on physical and mental health, mental and physiological performance, and sleep. Absent any intervention, the circadian system adjusts only 0.5-1.0 h per day to a shifted light-dark and sleep-wake schedule. Bright light facilitates circadian adjustment, but in field studies, bright light is only modestly better than no stimulus. Evidence indicates that exercise and melatonin can be combined with bright light to elicit larger shifts but no study has combined all of these stimuli or administered them at the times that are known to elicit the largest effects on the circadian system. The aims of this study are to compare the effects of different treatments on circadian adjustment to simulated jet lag in a laboratory. Following 2 weeks of home recording, 36 adults will spend 6.5 consecutive days in the laboratory. Following an 8 h period of baseline sleep recording on the participant's usual sleep schedule on Night 1 (e.g., 0000-0800 h), participants will undergo a 26 h circadian assessment protocol involving 2 h wake intervals in dim light and 1 h of sleep in darkness, repeated throughout the 26 h. During this protocol, all urine voidings will be collected; mood, sleepiness, psychomotor vigilance, and pain sensitivity will be assessed every 3 h, forehead temperature will be assessed every 90 min, and anaerobic performance (Wingate test) will be tested every 6 h. Following, the circadian assessment protocol, the participant's sleep-wake and light dark schedule will be delayed by 8 h compared with baseline (e.g., 0800-1400 h), analogous to travelling 8 times zones westward. This shifted schedule will be maintained for 3 days. During the 3 days on the delayed schedule, participants will be randomized to one of 3 treatments: (1) Dim Red Light + Placebo Capsules, (2) Bright Light Alone, (3) Bright Light + Exercise + Melatonin. During the final 26 h, all conditions and measures of the baseline circadian protocol will be repeated. Acclimatization will be defined by shifts in circadian rhythms of aMT6s, psychomotor vigilance, Wingate Anaerobic performance, mood, and sleepiness, and less impairments in these measures during the shifted schedule compared with baseline. We posit that Bright Light Alone and Bright Light + Exercise + Melatonin will elicit greater shifts in circadian rhythms and less impairments in sleep, mood, performance, and sleepiness compared with Dim Red Light + Placebo Capsules. We also posit that Bright Light + Exercise + Melatonin will elicit greater shifts and less impairments than Bright Light Alone.