Change of rhythm in the summer

On the night from Saturday to Sunday, the hour hand on a watch simply jumps one step further. We runners will notice that at the beginning of the week.

Does the transfer of the one hour of daylight from the morning to the evening hours throw us out of rhythm? Does the one hour less sleep that we have to put up with this coming weekend affect us in the following days? If we are active in running, says a study published in 2021 by the University of Georgia, definitely yes!

On race days on the first day of daylight saving time, marathon runners ran around twelve minutes slower on average. For the study, the research team evaluated the results of 18 races on time change weekends in the period from 2000 to 2018 and compared the marathon and half marathon performances with the results of control events. This resulted in a somewhat imprecise comparison, also because external weather influences, for example, were not calculated as a factor. The conclusion of study co-author Patrick O'Connor: "Our bodies function best when our internal clock is in sync with environmental factors."

out of rhythm

The fact that runners run slower on average after the time change in spring is due to the supposedly marginal effect of an hour on our biorhythm. We humans are creatures of habit and are strongly influenced by rhythms. Among other things, our body learns when and under what conditions we are most efficient in sports. The change in time throws him out of rhythm, until after a few days he has realigned and settled in. Also, the importance of good sleep as our main source of regeneration cannot be overstated.

The often underestimated influence of the time change twice a year (in North America, by the way, not at the same time as in Europe, summer time is longer there) is also an indication of what traveling between time zones does to us. "If these arrhythmias are repeated constantly and over a long period of time, it can lead to serious illnesses," warns Dr. Maximilian Moser, one of the leading local scientists in chronobiology, in an interview with the running magazine RunUp in 2018 ("In the rhythm of life") and proves this with study findings.

meaningful adaptation processes

Running, especially marathon running, was before the pandemic, and likely will be again in the future, also a tourism travel business with the run as part of an experience package. When traveling to the New York City Marathon, for example, you need to plan for jet lag. In such cases, Moser recommends that you be prepared for the destination time of your whereabouts when you leave the airport at the latest. In top-class sport, the findings from chronobiology have long been an important part of the overall concept, as the preparations for the Olympic Games in Tokyo last summer showed.

Individually, the effect can be mitigated by targeted adaptation strategies. In the example of the time change, a gentle adjustment to going to bed earlier can ease the transition from winter to summer time. Anyone who has small children who do not adhere to technical time specifications, but who have just learned their day-night rhythm naturally, may be familiar with these gentle adaptation processes as a strategy. Diet can also support the adjustment process of the circadian rhythm. For example, late-morning caffeine or late-night alcohol are generally not conducive to good sleep, especially if you're planning on going to bed earlier than usual -- even if it's just 20 minutes.

Running pleasure in the summer time

If you are planning a run on Sunday, prepare carefully and get enough sleep the night before. If things don't run quite so smoothly, the time change may be a contributing factor. Enjoy your run at the start of summer anyway!

Reading Tips:

RunUp interview with the Austrian chronobiologist Dr. Maximilian Moser: "In the rhythm of life"

University of Georgia study