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Morning, day, or evening chronotypes differ by the circadian timing of alertness and the preferred timing of sleep. It has been suggested that evening chronotype is associated with low physical activity (PA) and high sedentary time (SED). Our aim was to investigate whether such an association is confirmed by objectively measured PA and SED. In 46-year follow-up of the Northern Finland Birth Cohort 1966 study, total PA (MET min/day) and SED (min/day) among 5156 participants were determined using wrist-worn accelerometers for 14 days. We used the shortened Morningness-Eveningness Questionnaire to define participants' chronotypes. As covariates, we used self-reported physical strenuousness of work, health, and demographics, and clinical measures. We used adjusted general linear models (B coefficients with 95% confidence intervals, CI) to analyze how chronotype was related to total PA or SED. As compared to evening chronotype, men with day and morning chronotypes had higher total PA volumes (adjusted B 75.2, 95% CI [8.1, 142.4], P = .028, and 98.6, [30.2, 167.1], P = .005). Men with day and morning chronotypes had less SED (-35.8, [-53.8, 17.8], P < .0001, and - 38.6, [-56.9, -20.2], P < .0001). Among women, morning chronotype was associated with higher total PA (57.8, [10.5, 105.0], P = .017), whereas no association between chronotype and SED emerged. Evening chronotype was associated with low objectively measured PA in both sexes and with high SED in men, even after adjustments for established potential confounders. Chronotype should be considered in PA promotion.

Purpose: To compare training load and energy expenditure during an 8-week military BT period among individuals having different fitness level using objective measurements in an authentic environment. Methods: Thirty-four voluntary male conscripts (age 19.1±0.3 years) were divided into three training groups (inactive, moderate, active) by their reported physical activity (PA) level evaluated by the International Physical Activity Questionnaire (IPAQ) prior to military service. Maximal oxygen uptake (VO2max) and heart rate (HR) were determined by maximal treadmill test in the beginning and after 4 and 7 weeks of BT. During BT, HR monitors and accelerometers were used to measure PA and energy expenditure. HR data were used to calculate the training load (TRIMP, training impulse) for each day, week and the whole BT period. Results: Training load of BT was comparable to training of competitive athletes at the highest level. The training groups differed (p

ObjectivesThis is the first general population study to evaluate whether evening chronotypes (E) have poorer work ability (WA) and higher probability for early disability pensions (DPs) than morning types (M) in middle age.MethodsAmong non-retired individuals (n=5831; 2672 men, 3159 women) of the Northern Finland Birth Cohort 1966, chronotype was determined at the age of 46 years with shortened Morningness–Eveningness Questionnaires in 2012. The outcomes were poor WA in 2012, indicated by scores 0–7/10 of Work Ability Score, and registered emergence of DPs in 2013–2016. Multivariate logistic and Cox regression analyses were separately adjusted for factors related to sleep, health and behaviours, sociodemographic and economic factors, or working times.ResultsE-types represented 10% (n=264) of men and 12% (n=382) of women. Compared with M-types, the unadjusted ORs with 95% CIs of poor WA for E-type men and women were 2.24 (95% CI 1.62 to 3.08) and 2.33 (95% CI 1.74 to 3.10), respectively. The odds remained statistically significant and approximately twofold in all separate adjustment models tested. During 2013–2016, 8 (3.0%) E-type men and 10 (2.6%) E-type women were granted DP, which, compared with M-types, represented a higher HR that was statistically significant for men (HR 3.12, 95% CI 1.27 to 7.63) and remained significant except when multiple sleep variables or working times were adjusted for.ConclusionsEveningness appears a previously unrecognised risk factor for poor WA and early disability. We suggest that individual chronotype be considered in attempts to lengthen work careers.

Rapid travel over multiple time zones usually results in transient de-synchronization between environmental time and the biological clock of the individual. Common symptoms are increased daytime sleepiness, reduced sleep duration and quality, and performance impairments. Exposure to ocular bright light is known to alleviate jet lag symptoms and facilitate adaptation to a new time zone. Recently, transcranial bright light (TBL) via the ear canals has been shown to have antidepressant, anxiolytic, and psychomotor performance-enhancing effects. In this case we studied whether intermittent TBL exposure can alleviate jet lag symptoms in a randomized, double-blind, placebo-controlled study.Intermittent light exposures (4 × 12 min; day 0: 08:00, 10:00, 12:00, 14:00; days 1-6: 10:00, 12:00, 14:00, 16:00) were administered during the 7-d post-travel period after an eastward transatlantic flight. The symptoms of jet lag were measured by the Visual Analog Scale (VAS), the Karolinska Sleepiness Scale (KSS), and the Profile of Mood States (POMS).We found a significant reduction of overall jet lag symptoms (VAS), subjective sleepiness (KSS), and the fatigue, inertia, and forgetfulness subscales of the POMS when comparing the active TBL treatment group (N = 30) to the placebo group (N = 25). For example, the normalized values of VAS in the TBL, but not the placebo, group returned to pre-travel levels by the final post-travel day (6.16 vs. 15.34).Results suggest a cumulative effect of TBL, as the effects emerged on post-travel days 3-4. Intermittent TBL seems to alleviate jet lag symptoms.

We investigated whether transcranial bright light (TBL) affects nocturnal melatonin and cortisol secretion in sham-controlled crossover trial. Young healthy adults were exposed in random order to 24 minutes of TBL or sham exposure via ear canals at 01:10 h. Saliva and urine samples were collected hourly between 21 h-03 h and 06 h-09 h. There were no significant differences in melatonin or cortisol concentrations between TBL and sham exposures at any sampling point indicating that TBL via ear canals does not suppress nocturnal melatonin secretion. Thus, non-visual effects of TBL are mediated via a pathway not involving melatonin suppression.

Purpose: A recent study suggests that transcranial brain targeted light treatment via ear canals may have physiological effects on brain function studied by functional magnetic resonance imaging (fMRI) techniques in humans. We tested the hypothesis that bright light treatment could improve psychomotor speed in professional ice hockey players. Methods: Psychomotor speed tests with audio and visual warning signals were administered to a Finnish National Ice Hockey League team before and after 24 days of transcranial bright light or sham treatment. The treatments were given during seasonal darkness in the Oulu region (latitude 65 degrees north) when the strain on the players was also very high (10 matches during 24 days). A daily 12-min dose of bright light or sham (n = 11 for both) treatment was given every morning between 8 and 12 am at home with a transcranial bright light device. Mean reaction time and motor time were analyzed separately for both psychomotor tests. Analysis of variance for repeated measures adjusted for age was performed. Results: Time × group interaction for motor time with a visual warning signal was p = 0.024 after adjustment for age. In Bonferroni post-hoc analysis, motor time with a visual warning signal decreased in the bright light treatment group from 127 ± 43 to 94 ± 26 ms (p = 0.024) but did not change significantly in the sham group 121 ± 23 vs. 110 ± 32 ms (p = 0.308). Reaction time with a visual signal did not change in either group. Reaction or motor time with an audio warning signal did not change in either the treatment or sham group. Conclusion: Psychomotor speed, particularly motor time with a visual warning signal, improves after transcranial bright light treatment in professional ice-hockey players during the competition season in the dark time of the year.

Bright light therapy (BLT) is widely accepted as first-line treatment of seasonal affective disorder (SAD). However, the mechanism of action of BLT is still widely unknown. On the other hand, in mammals, light penetrates the skull bone and reaches the brain, and extra ocular transcranial phototransduction has physiological influences such as changed reproductive cycles and increased brain serotonin levels. Therefore, we challenged the existing conceptual framework that light therapy would only be mediated through the eyes. Consequently, we run a pilot study on the putative effect of transcranial bright light in the treatment of SAD. The light was produced using light-emitting diodes (LEDs), which were attached to earplugs. The amount of photic energy was 6.0-8.5 lumens in both ear canals, and the length of treatment was 8 or 12 min five times a week during a four-week study period. Subjects were recruited through advertisements in the city of Oulu, Finland (latitude 65°01'N) during 14 January 2009-03 February 2009. The final patient series consisted of 13 (aged 37.1 ± 7.2 years) physically healthy indoor workers suffering from SAD according to DSM-IV-TR criteria. Severity of depressive symptoms was assessed using the 17-item Hamilton Depression Rating Scale (HAMD-17) and Beck Depression Inventory (BDI)-21. Furthermore, severity of anxiety symptoms was measured by the 14-item Hamilton Anxiety Rating Scale (HAMA). The HAMD-17 mean sum score at screening was 23.1 ± 1.6. Ten out of 13 SAD patients (76.9%) achieved full remission (i.e., HAMD-17 sum score ≤ 7), and 92.3% (12/13) at least 50% reduction in HAMD-17 sum scores at "Week 4". By using a mixed regression model of repeated measures (AR-1) controlling for age, gender, and HAMD-17 mean sum score at screening, significant differences were found comparing the HAMD-17 mean sum scores of "Week 0" with the corresponding scores at the "Week 3" (t=-2.05, p=0.045) and "Week 4" visit (t=-2.77, p=0.008). Correspondingly, significant differences were found comparing the BDI-21 mean sum scores (15.2 ± 6.7) of "Week 0" with the corresponding scores at the "Week 3" (t=-2.37, p=0.021) and "Week 4" visit (t=-3.65, p

Introduction Bright light therapy acutely reduces anxiety in patients suffering from Seasonal Affective Disorder (SAD) and in low anxious subjects. Further evidence suggests it might also be effective in highly anxious subjects. Transcranial bright light (TBL) seems to alleviate depressive symptoms in SAD patients. Objectives Depression and anxiety commonly co-occur, hence TBL might also have anxiolytic effects. Aim To test the acute anxiolytic effects of TBL exposure. Methods Twenty-eight participants (F=19, M=9, mean age ± SD: 44 ± 14 years) with moderate anxiety and depressive symptoms (Beck Anxiety Inventory: mean ± SD: 19 ± 9; Beck Depression Inventory-II: mean ± SD: 21 ± 9) were randomly assigned to either 12 minutes of TBL or sham exposure (double-blind) under laboratory conditions between 9am and 12am. Acute anxiety symptoms were measured using the Spielberger State-Trait Anxiety Inventory (STAI-Y1) 5 minutes prior and 10 minutes after the exposure. Results Mean anxiety symptoms (STAI-Y1 score) in the TBL group decreased by 12.1 ± 7.3% from 43.7 ± 2.0 to 38.1 ± 1.4 (p Conclusion This is the first randomized, sham-controlled study showing that TBL acutely alleviates anxiety symptoms. Further studies on long-term efficacy of TBL therapy for anxiety symptoms are warranted.

Bright light treatment is effective for seasonal affective disorder (SAD), although the mechanisms of action are still unknown. We investigated whether transcranial bright light via the ear canals has an antidepressant effect in the treatment of SAD. During the four-week study period, 89 patients (67 females; 22 males, aged 22-65, mean ± SD age: 43.2 ± 10.9 years) suffering from SAD were randomized to receive a 12-min daily dose of photic energy of one of three intensities (1 lumen/0.72 mW/cm2; 4 lumens/2.881 mW/cm2; 9 lumens/6.482 mW/cm2) via the ear canals. The light was produced using light-emitting diodes. The severity of depressive symptoms was assessed with the Hamilton Depression Rating Scale – Seasonal Affective Disorder (SIGH-SAD), the Hamilton Anxiety Rating Scale (HAMA), and the Beck Depression Inventory (BDI). Cognitive performance was measured by the Trail Making Test (TMT). The within-group and between-group changes in these variables throughout the study were analysed with a repeated measures analysis of variance (ANOVA), whereas gender differences at baseline within the light groups were analysed using Student’s t-tests. Patients in all three groups showed significant decreases in their BDI, HAMA, and SIGH-SAD scores. Response rates, i.e., an at least 50% decrease of symptoms as measured by the BDI, were 74%-79% in the three treatment groups. Corresponding variations for the SIGH-SAD and the HAMA were 35-45% and 47-62%, respectively. No intensity-based dose-response relationships in the improvement of anxiety and depressive symptoms or cognitive performance between treatment groups were observed. Approximately one in four patients experienced mild adverse effects, of which the most common were headache, insomnia, and nausea. These results suggests that transcranial bright light treatment may have antidepressant and anxiolytic effect in SAD patients, as both self- and psychiatrist-rated depressive and anxiety symptoms decreased in all treatment groups. These improvements are comparable to findings of earlier bright light studies that used conventional devices. The lack of dose response may be due to a saturation effect above a certain light intensity threshold. Further studies on the effects of transcranial bright light with an adequate placebo condition are needed. NCT01293409 , ClinicalTrials.gov