Chronobiology is the scientific discipline that studies the rhythms and “internal clocks” of the human body (body-clocks), this is, our temporal organization as the alterations and mechanisms regulating it. These rhythms and clocks are sleep-wake cycles, mood and performance states.
Sports chronobiology is the area that investigates the moments of the day where we get our best performance. For example, some of us have a better performance in the morning than the afternoon, since our physiological and psychological functions fluctuate in relation to the different moments of the day. These variations also affect sports performance interfering in motor executions.
According to Reilly & Waterhouse (2009), the factors influencing sports performance would be:
- External factors: such as temperature, physical or psychological stimulation of the environment.
- Internal factors (physiological): as biological rhythm, lifestyle factors (psycho-biological) such as the preference of activities timetable, sleep patterns, and sleep inertia.
During the day there are normally two periods where our functional skiing capacity increases, which are from around 10 a.m. and 1 p.m., and from 3 p.m. to 5 p.m. Performance partially deteriorates after lunch even without having digested food. Cappaert (1999) proposes that peak performance is reached in the afternoon, coinciding with our body temperature apex.
Some authors mention that in sports with fine motricity and greater control as skiing, performance is better in the morning because of our lower arousal. Others emphasize that during mornings, short-term memory has greater reach and is consistent with the period of higher alert.
Also, several studies agree that it is during the afternoon when our performance reaches its peak along with body temperature. The significance of our body temperature follows the idea that the best results are obtained by an appropriate warm-up before skiing. In general, performance is lower in the first hours of the day and the last of the afternoon. I observed that most skiers experience a better mental and physical state in the morning until performance slowly decreases.
It has been investigated how circadian rhythm influences our physical performance due to hormonal changes and body temperature. Our functioning parameters such as body temperature, hormone concentration, blood pressure, and muscle strength are not constant throughout the day since they vary according to cycles that recur every day. The variable aspects are movement amplitude, muscle power, cardio-respiratory resistance, and muscular endurance. This has been proven because sports world records are normally reached in the afternoon, a time that coincides with the highest point of body temperature.
The alert state is an attentional control attitude that includes, among other aspects, selective attention, vigilance, and observation. The opposite is the fatigue state referring to the loss of desire and/or ability to continue with the activities.
Although these are generalizations, paying attention to our personal fluctuations in energy and alertness during different day times helps us to recognize and to adjust our performance patterns, optimizing skiing time.
Synchrony effect
According to May & Hasher (1998), there would be a performance benefit by coordinating activities with the optimal daytime. These authors refer to the synchrony effect where our performance is optimal when activities coincide with peak stimulation periods of our own circadian rhythm.
According to this approach, optimal and non-optimal moments exist in daily skiing activities. During optimal moments, we tend to use more difficult decision patterns including analysis and evaluations. In non-optimal moments we are likely to have less control over our attentional process, the ability to ignore distractions and assess appropriate responses is reduced, there is a tendency to have difficulty in remembering and using simple and more accessible decision patterns.
