Since the start of the school year, fatigue has crept in gradually, often without you noticing. It is there the moment you get out of bed and lingers until evening, when you nod off in front of a film or while reading a book. Add the mid-afternoon slump at work, and the simplest tasks become a struggle. Alongside this exhaustion, a touch of the blues can make the seasonal shift even harder to bear.
This passing fatigue, combined with a dip in mood, is relatively common and is explained by the change of season, according to nurse Rebecca Kaplan of Hartford Hospital in Connecticut. Once autumn sets in, she says, it is normal to feel a drop in energy, particularly once the days really start to shorten. “Changes in light, sleep schedules and daily habits can all influence your energy level,” the health professional explains.
Shorter Days Disrupt the Body’s Internal Clock
The reason the drop in light during autumn is so tiring lies in the way it disrupts our internal clock, which regulates our cycles of wakefulness and rest.
In the evening, when the sun sets earlier, “the lack of stimulation from sunlight triggers the early release of melatonin, the hormone that prepares the body for sleep. It is hardly surprising that we want to curl up on the sofa,” explained general practitioner and psychotherapist Adrian Chaboche.
In the morning, the lack of light is also to blame for our difficulty waking up, as it upsets the production of cortisol, the hormone that helps the body shake off the torpor of sleep. As a result, “our rhythm is thrown off, and we feel tired for longer in the morning,” said Julie Salomon, a pediatrician at Necker-Enfants Malades hospital and medical director of the Qare platform.
To regain energy, Kaplan advises getting outside early in the morning to make the most of the first rays of sunlight, and paying attention to sleep hygiene, since keeping regular bedtimes and wake-up times is the best way to adapt to the changing season.
The Time Change Makes Fatigue Worse
Not everyone is affected equally by this seasonal fatigue. While some feel it as soon as September arrives, others mainly notice the effects when the clocks change.
The switch to winter time — set for the night of October 25 to 26 — is another challenge for the body, not only because of reduced light but also because the new schedule generally forces us to go to bed later. It can cause “a feeling of drowsiness, apathy, stress and fatigue for a period of time,” explained a professor of environmental health at Rutgers University in New Jersey in 2024. “Sometimes fatigue is simply due to a lack of regular, restorative sleep,” Kaplan adds. “If you go to bed late but get up early, those lost hours of sleep can add up.”
As if the drop in light and the time change were not enough, autumn is also the season when colds, flu, stomach bugs and Covid reappear — all of which can add to our fatigue. “Your body uses a lot of energy when fighting an infection,” Kaplan says. “It is normal to feel tired during an illness or for some time afterward.”
Eat Well and Sleep Well to Recover
To combat seasonal fatigue, it is important to take care of yourself — and above all, of your sleep. In addition to keeping a regular bedtime and wake-up schedule, doctors recommend listening to your body and going to bed at the first signs of tiredness, such as stinging eyes or yawning.
“Rest is beneficial because it allows the body to regenerate. It is thanks to sleep that we gain energy and that our body recovers from the efforts of the day. It is also when we digest what we have learned and consolidate our memories,” Dr. Chaboche noted earlier this year.
Dr. Salomon also advises “eating a balanced diet to vary your intake, with seasonal fruits and vegetables, oily fish, nuts and legumes,” and not forgetting to get regular physical activity.
Sometimes, however, fatigue sets in for the long term and is not relieved by restorative sleep and a healthy lifestyle. In that case, it is important not to hesitate to seek medical advice. “Persistent fatigue is a problem that only your doctor can help you identify. If rest does not relieve you and you do not feel well, speak up,” Kaplan advises.
