Chronotype and response to training during the polar night: a pilot study

Abstract

Background: An individual’s chronotype influences his or her physiological rhythms. Some studies have looked at the effect of time of day on the responses to exercise, but studies on the effect of long-term training are lacking.Objective: To report the effects of an 8-week training period during the polar night in non-athletes of different chronotypes living at 70°N.Design: In all, 10 morning (M), 10 neither (N) and 10 evening (E) types were recruited, and their aerobic capacity (VO2max), strength, flexibility and balance before and after the training period were tested.Results: 3 E-types, 5 N-types and 6 M-types completed the protocol. An increase in VO2max and strength was observed for the whole group. The best negative correlation (r=–0.5287) was found between the Morningness–Eveningness Questionnaire (MEQ) score and the increase in VO2max, and the best positive correlation (r=0.4395) was found between MEQ and the increase in strength. Changes in balance and flexibility did not show any clear trends.Conclusion: In an environment with no outdoor daylight, it seems that the response to 8 weeks of aerobic training is larger in the E- than in the M-types, although the M-types showed a larger improvement in strength.

Biological rhythms, chronodisruption and chrono-enhancement: The role of physical activity as synchronizer in correcting steroids circadian rhythm in metabolic dysfunctions and cancer

“…It is crucial, in future longitudinal studies, to control for potential confounding factors, such as competing synchronizers, noncontrolled diet, environmental conditions, exercise characteristics (time of day, mode, intensity and duration), and inter-individual variability with the aim to reduce the methodological bias. With reference to the inter-individual variability, it results essential to highlight that the subjects' chronotype is able to largely influence and affect behavioural, physiological, and bio-psychological characteristics and, consequently, the circadian system in general (Adan et al, 2012;Bonato et al, 2017a;Bonato et al, 2017b;Montaruli et al, 2017;Rossi et al, 2015;Roveda et al, 2017a;Vitale et al, 2013;Vitale et al, 2015;Vitale et al, 2017a;Vitale et al, 2017b;Vitale et al, 2017c;Vitale et al, 2017d). The correct chronobiologic approach to the problem and the standardization of all confounding factors are needed to reach more clear evidence-based results.…”

Effects of altitude on chronotype orientations in relation to cardiorespiratory and hematological quantities of college students in Ethiopia

“…Our finding further reported no significant difference on Vo 2 Max and hematological quantities between I-type and M-type chronotype among students from low altitude living in a tropical setting. However, previous studies reported a better VO 2 max in E-types than M-types [68,70–72]. This might be reflective of better aerobic participation in energy metabolism during the evening time, leading to both mental and physical activeness among E-type than other chronotype [16,36,73].…”

Sleep quality and athletic performance according to chronotype

“…Everyone has a biological or circadian rhythm, determined by various hormones [ 4 ]. Regulates the sleep/wake system and many other features such as blood pressure, hormone levels, body temperature, physical performance, alertness, mood, and intellectual ability to fluctuate during the day [ 5 ].…”