Beware the morning light. Yes, you read that right.
Your body clock doesn’t read the wall clock. For several days after the “time change”, it still runs an hour ahead. Cortisol rises early, so you wake at 5:30 instead of 6:30. Melatonin arrives early, so you’re fading by 9 instead of 10.
So how can your body catch up?
Meet the PHASE RESPONSE CURVE (PRC)
The PRC is one of the most useful things to know about your sleep. It shows that the timing of your light can move your body clock earlier or later.
- Evening light shifts your clock LATER
- Early morning light shifts your clock EARLIER
Remember our summer post on why it’s so hard to fall asleep on long summer nights where Dr. Ivanhoe explained that late evening light pushes your clock later.
After we fall back, it’s the opposite. Your body needs to shift later and evening light is what helps.
Most advice says to get morning light. That’s right for springing forward, for keeping a steady rhythm, or if you want to shift to an earlier bedtime and wake-up.
But if your rhythm is working for you and you just want it to adjust to the new clock, this week is different.
For fall back, morning light alone can keep you stuck on early wake ups.
What to do this week:
- Get outside in the late afternoon or before sunset
- Keep your evenings a little brighter for the first few nights Sleepy early? Try to hold off until your usual bedtime on the new clock
- Eat dinner at your usual clock time. Meals are a strong body-clock cue too.
Or here’s another option: do nothing.
Your body will adjust on its own in about a week or so. What would it feel like to let it?
How does falling back hit you? Early riser, night owl, or barely notice? Take a moment to journal about it.
