Training time and adaptation to lack of daylight: a case report

Abstract

A pilot study was conducted to describe the reaction to lack of daylight and different training times of circadian rhythms and sleep in a subject arriving in Alta (Northern Norway) from Milan (Italy) in the darkness period. Monitoring sessions by heart rate (HR) monitor and actigraph were performed after four conditions: MS1, no training in Italy; MS2, no training in Alta (lack of daylight); MS3, evening training in Alta; and MS4, morning training in Alta. Midline Estimating Statistic Of Rhythm (MESOR) for activity was lower in MS2 than in MS1, MS3 and MS4, and decreased progressively for HR. Acrophases were advanced in MS2 and MS4 compared to MS1 and MS3 for both activity and HR. Sleep Efficiency was higher in MS2, MS3 and MS4 compared to MS1, coinciding with low values in the Mean Activity Score and Movement and Fragmentation Index. It could be seen that lack of daylight induced a decrease of the activity state in the subject, advancing the acrophase and leading to increased sleep.After the exercise sessions the activity state of the subject increased and the circadian structure was influenced according to the time at which the training was performed.

Morning or evening exercise: effects on the heart rate circadian rhythm above the Arctic Circle

“…2) showed that in the winter session there was a shift in the HR circadian rhythm with evening exercise, with a delay in the HR acrophase compared with both morning exercise and control (2 h 58 min and 1 h 37 min, respectively; mean acrophase values). This is consistent with the findings of previous studies [25,30]. In contrast, in the May session no shift in rhythm was seen.…”

“…In 2009, we reported the results of a pilot study that took place at 70° North during the sunless winter 10 (January) [30]. The results indicated that periods of outdoor exercise repeated for four consecutive days in two separate time-blocks (0900-1100 hours and 1800-2000 hours) induced a phase shift in the HR circadian rhythm, confirming our previous findings [25].…”

Biological Rhythm and Chronotype: New Perspectives in Health

“…Circadian rhythms of activity levels can be assessed through an objective approach and method: actigraphy [ 40 ]. Actigraphy is based on the use of an actigraph, a device containing a piezoelectric triaxial accelerometer that is able to record movement during the day and sleep parameters during the night [ 17 , 41 , 42 , 43 , 44 ]. An actigraph is similar to a watch and worn on the wrist of the non-dominant hand for at least 7 continuing days.…”

Effects of Sleep Loss and Strenuous Physical Activity on the Rest–Activity Circadian Rhythm

“…Because of its modulating effects on the circadian system, physical activity might influence sleep patterns. However, few data concerning how exercise-induced modifications of the circadian structure influence nocturnal sleep are available (Calogiuri et al, 2009; Mischler et al, 2003).…”