owl or lark?

Chronobiology provides us with many important insights into

• what influence (social) jetlag has on our endgenous clock,
• how the times of performance peaks and performance troughs differ individually, and
• what options are there to harmonize the performance peak as best as possible with the required time of successful delivery of maximum performance.

What chronotype are you?

In order to find out which sleep type you belong to, you first have to know when chronobiologists speak of an owl and when of a lark. There are a few clues to this.
You are considered to be in the range of “lark” chronotypes if during vacation

• You wake up and are fit at six o'clock in the morning,
• Experience your peak performance between 3:00 p.m. and 5:00 p.m.
• Prefer to go to bed around 10:00 p.m.

You are considered to be an “owl” chronotype if during vacation

• You prefer to get up at 9:00 a.m. or later
• Reach your peak performance between four in the afternoon and nine at night.
• You are regularly awake until 1 a.m. or later.

Why is the time of day crucial for your competition performance and for your training?

Depending on your chronotype, you have your cognitive and physical highs at different times of the day, and your lows at other times of the day. Everyone has certainly already noticed at some point in their own lives that performance during training at 6 a.m. is different than at 5 p.m. The background to this is the physiological and biochemical processes in our body that depend on the time of day and are driven by an internal circadian clock (see: chronobiology): the concentration of important hormones in our body is also subject to a rhythm that is dependent on the time of day:

• cortisol rises in our blood even before we wake up, even during sleep, so that we are fit quickly after we get up. As a catabolic hormone, cortisol promotes, among other things, the breakdown of proteins and thus gluconeogenesis, which is so important for our sporting activities and which provides our body with sufficient amounts of glucose during training and competitions.
   
• Testosterone is a sex hormone found in different amounts in both women and men. It has a daytime high in the morning. As an anabolic hormone, it increases the build-up of muscle mass, among other effects.
   
• Melatonin is only formed immediately before and during the night, induces sleepiness and thus tells the body, among other things, when sleep is due.
   
• Growth hormones play a major role especially during human development, but are still prevalent in adults where they increase in particular during the night.

A disruption of the circadian rhythms of these hormones, e.g. due to jetlag, will inevitably lead to reduced performance on the day of the competition. Since the phase of the hormone rhythms also depends on your chronotype, you should know whether you are a lark or more of an owl and adjust the phase of your body clock accordingly to the start time, if you want to train efficiently and get your maximum performance on the day of the competition.

Get up early on Sunday and soak up the sun - Interview with Prof. Jörg Stehle on changing to daylight-saving-time.