The biorhythm keeps time

12. June 2019

Various studies have shown that the performance capability of athletes can vary by up to 25 percent in the course of one day.

It is a well-known phenomenon: there are the «larks» (early risers) among us, who can tear out trees at different times of the day than the «owls», who are either referred to as «night owls» or «morning grouches». However, the two different types say nothing about their respective levels of fitness - the overall constitution of the alleged morning grouch can be just as good as the merry lark - or even better. It’s just that both types perform at completely different times of the day.

Discipline is not always beneficial

It was not so long ago that people thought discipline and the appropriate adjustment period could «change» the biorhythm. In other words: those who find it somewhat hard to get out of bed in the morning only needed a while to «pull themselves together» in order to cheerfully do lengths in the pool at around 6:30 in the morning along with their lark colleagues. And apparently this was and is actually possible for many «owls» too – after all, the will can move mountains.

However, we now know that while the «owls» are able to force their bodies into an unpleasant temporal rhythm, their respective performance capability by no means adapts to the new rhythm. Or, to put it another way: larks remain larks and owls remain owls, regardless of discipline, self-control, and training.


Genetics are decisive

The reason: the biorhythm is genetically anchored and can only be changed from «outside» by a dwindling small amount. The internal clock differs from person to person and is apparently firmly anchored in each individual. The earlier assumption that athletes are capable of peak performances especially in the late afternoon and early evening hours is only partially true, specifically when it comes to the owl type. At this time of day, the performance curve of larks tends to take a steep dive.

In a study by the British biochemist Elise Facer-Child and the German Roland Brandstaetter from the University of Birmingham, they initially determined the biorhythms of test persons by questioning their sleeping and getting-up behaviour as well as their perceived performance peaks during the day. It became clear that – not surprisingly, but scientifically substantiated by the investigations – the individual types clearly displayed significant differences in performance at the respective times of the day depending on their internal clock.

Differences of up 26 percent

It was interesting to note that the timing of the different biorhythm types was also different. The early and medium types reached their peak physical performance around six hours after waking or getting up, thus between noon and the early afternoon. The owls, on the other hand, reached their top form much later on - not until eleven hours after their alarm clocks rang.

In the “Facer-Child/Brandstaetter Study”, the owls also showed the most significant performance differences within one day. Their performance fluctuated by up to 26 percent between low (in the morning) and high (in the evening). In contrast, the performance of the larks and medium types fluctuated by eight and ten percent in the course of one day. The performance of the early risers and medium types (by far the largest percent of the people being tested) is thus more balanced throughout the day.


«Owls» are hardly likely to become world champions

Depending on the competition, this means fatal prospects for an owl athlete. Because the late risers among athletes are clearly disadvantaged in many types of sports. Particularly long endurance sports competitions, such as long triathlons, ultra runs or even marathons or long bike races generally start early in the morning. It’s not that the owls are disadvantaged because they could perhaps oversleep and miss the starting shot, but rather because their performance peaks are spread over unfavourable time periods. If we assume that «owls» with the will to win get up at around four or five in the morning, they will reach their biorhythmic performance peak between 14:00 and 16:00 – which is just right for the final spurt, or the award ceremony...

What does this finding mean for a hobby athlete? «We need to move away from the time of day», recommends Brandstaetter, «and pay more attention to the internal time rhythms». In this respect, it is not about the clock on the wall, but about the clock in us, adds Facer-Child. Training is one thing, the researcher continues, but you also need to know when you can summon your best performance! An insight that could play an important role, especially when it comes to the quality of training. Even for early risers, the morning forest run, very early swim, or «early morning bike tour» are only recommended as a «waker-upper» and for basic training, but not as an efficient key unit.

Credit: Trainer Academy