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.
The factors influencing skiing 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.
On-Slope Examples of Skiing Chronobiology
| Concept Name | Academic Core | “On-Slope” Example |
| Sports Chronobiology | The scientific study of how human physiological and psychological functions fluctuate across different times of the day to alter motor execution and athletic capability. | * An instructor notices that a student effortlessly handles technical carved turns at 10:30 AM but exhibits clumsy foot-timing on identical terrain right after lunch. |
| Peak Performance Periods | The two optimal daily intervals—typically from 10:00 AM to 1:00 PM and 3:00 PM to 5:00 PM—where functional skiing capacity naturally rises. | * Skiing down an un-groomed mogul field at 11:30 AM with fluid, automated knee and ankle retraction, feeling strong, centered, and fully alert. |
| Post-Lunch Performance Deterioration | A natural dip in functional physical and mental capacity that occurs early in the afternoon, independent of food digestion. | * Heading back onto the mountain at 1:45 PM and instantly feeling heavy, unmotivated, and prone to back-weighted posture collapses. |
| Body Temperature Apex | The late afternoon physiological peak where maximum body temperature aligns with optimal joint movement amplitude, muscle power, and endurance. | * Ripping down a steep black diamond run at 4:00 PM with immense physical leg power, setting deep, high-angle carves without experiencing thigh burning. |
| Fine Motricity Morning Benefit | The phenomenon where sports requiring high control and precision benefit from the lower autonomic arousal levels found in the morning. | * Executing highly precise, micro-movements of the ankles to cleanly slice across a sheet of smooth morning ice without over-flexing. |
| Alert State | An attentional control attitude encompassing selective focus, vigilant observation, and active hazard anticipation. | * Navigating a highly congested trail intersection while effortlessly tracking the moving paths of multiple skiers across your peripheral vision. |
| Fatigue State | The progressive loss of neurological motivation, focus control, and the physical ability to continue movements safely. | * Skiing toward the end of the day and blindly staring 2 meters ahead of your tips, completely missing an explicit orange “Slow” warning sign. |
| Synchrony Effect | The distinct motor benefit achieved when high-level athletic actions perfectly coincide with the peak stimulation periods of the circadian rhythm. | * Dropping into an unfamiliar, high-consequence off-piste face during an optimal window, seamlessly deploying complex tactical reasoning. |
| Non-Optimal Moments Block | A state where focus control is reduced, the capacity to ignore distractions collapses, and the brain struggles to use simple decision patterns. | * Skiing during a low-energy circadian dip; a sudden external distraction (like someone falling under the lift) completely captures your gaze and causes you to catch an edge. |
