Effects of bright light treatment on psychomotor speed in athletes

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 8–12 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 x 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

Peruskoulutuskauden fyysinen kuormittavuus varusmiespalveluksen aikana

Varusmiespalveluksen peruskoulutuskauden kokonaiskuormittavuudesta ei ole riittävästi tietoa. Verenkierto -ja hengityselimistön kunnon kehittyminen ja ylläpitäminen edellyttää riittävää fyysistä aktiivisuutta. Liiallinen ja pitkittynyt fyysinen kuormittaminen taas johtaa ylikuormitustilaan, josta seuraa suorituskyvyn laskeminen sekä muita fyysisiä ja psyykkisiä oireita. Tämän pro gradu -tutkimuksen tarkoituksena oli määrittää varusmiespalveluksen peruskoulutuskauden kuormittavuutta objektiivisillä mittausmenetelmillä aidoissa olosuhteissa. Kahdeksan viikkoa kestävään tutkimukseen osallistui 34 vapaaehtoista miesalokasta (ikä: 19.1±0.3 v) Kainuun Prikaatin viestikomppaniasta. Tutkittavat jaettiin varusmiespalvelusta edeltävän fyysisen aktiivisuuden perusteella aktiivi-, harraste- ja perustasoryhmään. Tutkimusjaksolla fyysistä kuormittavuutta ja energiankulutusta arvioitiin mittaamalla sykettä ja fyysistä aktiivisuutta. Kokonaiskuormittavuuden arvioimiseksi mitatusta sykedatasta laskettiin rasituskertymää päivä- ja viikkokohtaisesti sekä koko peruskoulutuskauden ajalle. Yksittäisten aktiviteettilajien intensiteettiä arvioitiin sekä sykeettä aktiivisuusmittausten avulla. Peruskoulutuskauden päivittäinen ja viikottainen fyysinen kuormittavuus (TRIMP) oli verrattavissa kestävyysurheilijoiden vastaaviin kokonaiskuormituksiin. Vähiten liikkuneet alokkaat kuormittuivat eniten (TRIMPperus=12393 vs. TRIMPharraste=10252, p<0.05 ja TRIMPaktiivi=8444, p<0.01) tutkimusjakson aikana huolimatta tasoryhmiin jakamisesta. Tämä oli havaittavissa päivä- ja viikkokohtaisissa, sekä koko tutkimusjakson aikaisessa kokonaiskuormituksessa. Intensiteetiltään peruskoulutuskauden aktiviteettilajit kuuluivat joko matalaan tai kohtalaiseen intensiteettiluokkaan (<6MET). Merkittävä kokonaiskuormittavuus aiheutui siten intensiteetin sijaan kuormituksen pitkästä kestosta. Eri mittausmenetelmillä arvioidut intensiteetit erosivat toisistaan suurimmassa osassa aktiviteettilajeja. Tutkimustulosten perusteella tasoryhmien kokonaiskuormituksen optimointi ei ollut peruskoulutuskauden aikana riittävää. Tasoryhmien fyysistä harjoittelua tulisi erilaistaa aiempaa voimakkaammin. Lisäksi varusmiespalveluksen kuormittavuutta tulisi jatkossa mitata myös palveluksen aikana, jotta fyysinen harjoittelu voitaisiin yksilöidä paremmin erikuntoisille alokkaille. Fyysisen aktiivisuuden ja sykemittauksen yhdistäminen antaisi mahdollisesti luotettavimman arvion energiankulutuksesta ja kokonaiskuormituksesta kenttäolosuhteissa.The amount of training load and energy expenditure during military basic training period is poorly known. In order to enchance and maintain aerobic performance, certain amount of physical activity is demanded. On the other hand, excessive and prolonged physical activity leads to overreaching state, which is followed by decresed physical performance and other physiological and psychological symptoms. The purpose of this study was to measure training load and energy expenditure during military basic training period using objective measurements in authentic environment. Thirtyfour voluntary male conscrispts (age: 19.1 ± 0.3 years) from Kainuu Pricade participated in this eight week study. Subjects were divided into three fitness groups (pro, semi, basic) by their physical activity state prior military service. During the study period heart rate monitors and accelerometers were used to evaluate physical activity and energy expenditure. Heart rate data was used to calculate the training load (TRIMP, training impact) for each day, week and the whole basic training period. The intensity of single activity was evaluated using both physical activity measurements. Training load of basic training period was remarkable and paralled with the training load of elite athletes during the training and competition period. The conscripts in the basic group were most loaded during the study period (TRIMPbasic=12393 vs. TRIMPsemi=10252, p<0.01 ja TRIMPpro=8444, p<0.05). The intensity of different physical activities during the basic training period were low or moderate (<6MET). Thus, the remarkable training load was rather due to extended duration of activity than high intensity. According to this study, the optimizing of training load into different fitness groups was not sufficient during the basic training period. Thus, the differentiation in training loads ought to be even stronger. In the future, measuring the training load during the military service is recommended in order to individualise the training load for each conscript. Combining of heart rate and physical activity measurements might give the best estimate of energy expenditure in field conditions

Transcranial bright light:the effect on human psychophysiology

Abstract In addition to the visual information, external light causes non-image-forming (NIF) effects that modulate brain function and induce psychophysiological effects. The light signal is traditionally assumed to only be mediated via the eyes. Recent studies have suggested the existence of putatively light sensitive structures in the rodent and human brain and penetration of light into the skull and brain tissue has been observed. The brain activation observed during transcranial bright light (TBL) exposure indicates a direct light responsivity of brain tissue. The aim of this thesis was to explore the psychophysiological responses related to TBL. The studies comprising this thesis were conducted in healthy subjects and patients suffering from seasonal affective disorder. TBL exposure was administered via the ear canals in all study settings using light-emitting diodes (LEDs). The comparisons in studies I, II, and III were conducted against the inactivated sham device. Study IV explored the effect of TBL dose. Neither melatonin nor cortisol secretions were altered when acutely exposed to nocturnal TBL. Circadian profiles in TBL setting were in parallel to control conditions for both hormones. Intermittent TBL exposure led to alleviation of jet lag symptoms. Overall post-travel jet lag symptoms as well as subjective feelings of fatigue, inertia, and forgetfulness were reduced. The time to execute the motor response i.e. motor time with a visual warning signal was improved by the TBL treatment. TBL alleviated both depressive and anxiety symptoms related to seasonal affective disorder (SAD). A dose-response relationship regarding the intensity of dose administered via the ear canals was not found. Altogether, TBL seems to affect human brain function by alleviating symptoms of jet lag and SAD and improving psychomotor performance. The acute effect is suggested to be mediated via structures unrelated to acute melatonin secretion i.e. the retinohypotalamic tract (RHT). These results support the light sensitivity of the human brain although the mechanism of action is not yet established.Tiivistelmä Visuaalisen informaation lisäksi valo aiheuttaa käytöksellisiä ja fysiologisia vaikutuksia, jotka eivät liity kuvan muodostamiseen. Yleisesti vaikutuksen ajatellaan välittyvän aivoihin ainoastaan silmien kautta. Viimeaikaiset tutkimukset ovat havainneet jyrsijöiden ja ihmisten aivoissa mahdollisesti valolle vasteellisia rakenteita. Valon on osoitettu lisäksi läpäisevän kallon ja saavuttavan aivokudoksen. Aivojen aktivoituminen kallon läpi annettavan valoaltistuksen aikana viittaa myös suoraan aivojen valovasteellisuuteen. Tämän väitöskirjan tavoitteena oli tarkastella vaikuttaako kallon läpi annettava valo ihmisen psykofysiologiaan. Tähän väitöskirjaan sisällytetyt tutkimukset tehtiin terveillä vapaaehtoisilla tutkittavilla ja kaamosmasennuspotilailla. Ledin avulla tuotettu valo annettiin kaikissa tutkimusasetelmissa korvakäytävien kautta. Tutkimukset I, II ja III tehtiin lumekontrolliasetelmassa. Tutkimuksessa IV tarkasteltiin valon annosvastetta. Akuutin yöaikaisen valoaltistuksen ei havaittu muuttavan melatoniinin tai kortisolin eritystä. Molempien hormonien vuorokausieritysprofiilit olivat kontrolliasetelman kaltaiset. Jaksottaisen valoaltistuksen havaittiin lievittävän aikaerorasituksen kokonaisoireita ja vähentävän väsymystä, inertiaa ja hajamielisyyttä. Motorisen nopeuden havaittiin paranevan kolmen viikon valohoitojakson aikana. Lisäksi neljän viikon valohoitojakso lievitti kaamosmasennukseen liittyviä masennus- ja ahdistusoireita. Vaikutuksessa ei havaittu eroa eri valoannoksen saaneiden ryhmien välillä. Kallon läpi annettava kirkasvalo näyttäisi vaikuttavan ihmisen aivotoimintaan lievittämällä aikaerorasituksen ja kaamosmasennuksen oireita sekä parantamalla psykomotorista suorituskykyä. Vaikutus ei ole yhteydessä akuuttiin melatoniinin erityksen estämiseen. Tämän tutkimuksen tulokset tukevat ajatusta aivojen valovasteellisuudesta. Kallon kautta annettavan valon vaikutusmekanismia ei kuitenkaan tiedetä vielä

Exercise energy expenditure estimation based on acceleration data using the linear mixed model

This paper introduces a novel algorithm for estimating energy expenditure during physical activity. The estimation is based on acceleration data measured from a wrist-worn accelerometer. Simultaneous measurements of acceleration and oxygen consumption using a biaxial accelerometer and a breath gas analyzer were made during four different ac-tivities: walking, running, Nordic walking and bicycling. A variance feature is used to compress the original accel-eration signals. A linear mixed model is fitted to the data to estimate oxygen consumption based on the acceleration data. Lagged values of acceleration are used to take the de-layed effect of physical activity on oxygen consumption into consideration. The algorithm also uses information on the height of the subjects. Oxygen consumption is estimated at 15-second intervals and energy expenditure is directly cal-culated from the oxygen consumption. Based on the experi-mental data gathered from 10 subjects, a new algorithm for estimating energy expenditure is suggested. It is shown that the method estimates energy expenditure very accurately. In walking, running and Nordic walking the model underesti-mates energy expenditure by 13, 2 and 9 percent, respec-tively, and in bicycling energy expenditure is overestimated by 7 percent. Thus, the new approach is a very promising method for estimating energy expenditure.

Training Load and Energy Expenditure during Military Basic Training Period

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<0.001-0.05) in terms of VO2max to each other (inactive 36±6, moderate 42±6, active 48±6 ml/kg/min). The conscripts in the inactive group were the most loaded during the study period (TRIMPinactive 12393±2989 vs. TRIMPmoderate 10252±1337, p<0.05 and TRIMPactive 8444±2051, p<0.01). The PA intensity of different military tasks during the BT period were low or moderate (<6MET). Conclusion: The remarkable training load during BT period is comparable to the training loads of professional athletes participating three weeks’ cycling competition. The training load in basic training period was, however, primary due to duration of low intensity activities including only some high intensity military activities. In the future, measuring the training load during the military service is recommended in order to customize the physical training for conscripts regarding his/her fitness level as much as possible.peerReviewe

Comparison and agreement between device-estimated and self-reported sleep periods in adults

AbstractObjectives Discriminating sleep period from accelerometer data remains a challenge despite many studies have adapted 24-h measurement protocols. We aimed to compare and examine the agreement among device-estimated and self-reported bedtime, wake-up time, and sleep periods in a sample of adults.Materials and methods Participants (108 adults, 61 females) with an average age of 33.1 (SD 0.4) were asked to wear two wearable devices (Polar Active and Ōura ring) simultaneously and record their bedtime and wake up time using a sleep diary. Sleep periods from Polar Active were detected using an in-lab algorithm, which is openly available. Sleep periods from Ōura ring were generated by commercial Ōura system. Scatter plots, Bland–Altman plots, and intraclass correlation coefficients (ICCs) were used to evaluate the agreement between the methods.Results Intraclass correlation coefficient values were above 0.81 for bedtimes and wake-up times between the three methods. In the estimation of sleep period, ICCs ranged from 0.67 (Polar Active vs. sleep diary) to 0.76 (Polar Active vs. Ōura ring). Average difference between Polar Active and Ōura ring was −1.8 min for bedtimes and −2.6 min for wake-up times. Corresponding values between Polar Active and sleep diary were −5.4 and −18.9 min, and between Ōura ring and sleep diary −3.6 min and −16.2 min, respectively.Conclusion Results showed a high agreement between Polar Active activity monitor and Ōura ring for sleep period estimation. There was a moderate agreement between self-report and the two devices in estimating bedtime and wake-up time. These findings suggest that potentially wearable devices can be interchangeably used to detect sleep period, but their accuracy remains limited.Key MessagesEstimation of sleep period from different devices could be comparable.Difference between sleep periods from monitors and sleep diary are under 20 min.Device-based estimation of sleep period is encouraged in population-based studies

Evening chronotype is associated with poor work ability and disability pensions at midlife:a Northern Finland Birth Cohort 1966 Study

Abstract Objectives: This 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. Methods: Among 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. Results: E-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. Conclusions: Eveningness 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

Validation of the Zung self-rating depression scale (SDS) in older adults

Abstract Objective: The main objective of this study was to investigate the psychometric properties of the Zung Self-Rating Depression Scale (SDS) and evaluate screening parameters capability of the SDS with the Beck Depression Inventory (BDI-21) among the elderly population. Design: A population-based study Setting: Community Subjects: 520 adults, aged 72–73 years, living in the city of Oulu, Finland. Main outcome measures: The screening parameters of the SDS questions and BDI-21 for detecting severity of depression. The Mini Neuropsychiatric Interview for diagnosing major depression. Results: The optimal cut-off point for the SDS was 39. The sensitivity and specificity parameters for this cut-off point were 79.2% (95% CI 57.8–92.9) and 72.2% (95% CI 67.9–76.1), respectively. Positive and negative predictive values were 12.5% (95% CI 7.7–18.8) and 98.6% (95% CI 96.7–99.5), respectively. Moreover, there was no statistically significant difference in diagnostic accuracy indices of the cut-off points 39 and 40. In a receiver operating characteristic analysis, the area under the curve was 0.85 (95%CI 0.77–0.92) for the SDS total score and 0.89 (95% CI 0.83-0.96) for the BDI-21 (p = 0.137). Conclusion: Using the traditional cut-off point, the SDS was convenient for identifying clinically meaningful depressive symptoms in an elderly Finnish population when compared with the BDI-21 which is one of the most commonly used depression screening scales. The sensitivity and specificity of these two screening tools are comparable. Based on our study, the SDS is convenient for identifying clinically meaningful depressive symptoms among older adults at the community level

Comparison and agreement between device-estimated and self-reported sleep periods in adults

Abstract Objectives: Discriminating sleep period from accelerometer data remains a challenge despite many studies have adapted 24-h measurement protocols. We aimed to compare and examine the agreement among device-estimated and self-reported bedtime, wake-up time, and sleep periods in a sample of adults. Materials and methods: Participants (108 adults, 61 females) with an average age of 33.1 (SD 0.4) were asked to wear two wearable devices (Polar Active and Ōura ring) simultaneously and record their bedtime and wake up time using a sleep diary. Sleep periods from Polar Active were detected using an in-lab algorithm, which is openly available. Sleep periods from Ōura ring were generated by commercial Ōura system. Scatter plots, Bland–Altman plots, and intraclass correlation coefficients (ICCs) were used to evaluate the agreement between the methods. Results: Intraclass correlation coefficient values were above 0.81 for bedtimes and wake-up times between the three methods. In the estimation of sleep period, ICCs ranged from 0.67 (Polar Active vs. sleep diary) to 0.76 (Polar Active vs. Ōura ring). Average difference between Polar Active and Ōura ring was −1.8 min for bedtimes and −2.6 min for wake-up times. Corresponding values between Polar Active and sleep diary were −5.4 and −18.9 min, and between Ōura ring and sleep diary −3.6 min and −16.2 min, respectively. Conclusion: Results showed a high agreement between Polar Active activity monitor and Ōura ring for sleep period estimation. There was a moderate agreement between self-report and the two devices in estimating bedtime and wake-up time. These findings suggest that potentially wearable devices can be interchangeably used to detect sleep period, but their accuracy remains limited

Chronotypes and objectively measured physical activity and sedentary time at midlife

Abstract 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 &lt; .0001, and − 38.6, [−56.9, −20.2], P &lt; .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.Correction In the abstract, a typo (missing − -sign) was corrected in the sentence : Men with day and morning chronotypes had less SED (−35.8, [−53.8, −17.8], p &lt; 0.0001, and −38.6, [−56.9, −20.2], p &lt; 0.0001)