Want to sleep better - take a warm bath before bed

July 29, 2019

That's it. It's all in the title. If you want to sleep better at night, take a warm bath 1-2 hours before bed.

Ok, how does it work? This is a bit counterintuitive. Your natural 24-hour circadian cycle has a lower temperature at night at part of that rhythm. In some folks, it can be as much as a couple of degrees. You sleep better in a cool room because it helps cool you down. And in these lazy dog days of summer, you may have a bit of trouble sleeping well when it stays too warm at night.

How does a warm bath cool you off? That's the interesting puzzle. When you warm up your skin with a shower, you dilate all your blood vessels over the surface of your body. Then, as you dry off you radiate off all your inner heat. The net effect, you are cooler an hour or so later. The fives minutes of warming is made up for by the hour of cooling.

How big an impact does it have? Well, if you take zolpidem every night to sleep, it allows you to fall asleep 16 minutes faster. And then you are addicted and can't get off of it. Take a warm bath and you fall asleep 7 minutes faster than controls. Cheaper, less addicting.

Or, you could just try taking some glycine at bedtime too. Glycine, simplest amino acid. Turns out it also helps cool you down at bedtime by its effect on NDMA receptors.

So, there you have it. Two nice strategies to help you get to sleep.

WWW: What will work for me. I've just changed my bath time. I going to try bedtime showering instead of morning. Check-in after a month and I'll let you know if it worked for me. And I ordered some glycine. And, I turned the AC down an extra degree last night.

Pop Quiz

  1. How much sooner do I fall asleep if I take a warm bath in the evening? Answer: About 9 minutes earlier than controls.
  2. How does that work? Answer: Paradoxically by dilating your surface blood vessels which is your natural radiator. You then dump all the heat stored up in your body that you naturally rid yourself of. If you are insulated with a layer of "insulation", it may take you longer to dump the heat.
  3. I thought I had the same temperature all day long? What gives? When is my temperature the highest and the lowest? Answer: It follows your circadian rhythm. You peak cortisol in the morning which generates the access to energy and then you peak your temperature in the afternoon, a couple of hours later. Lowest temps are then in the middle of the night.
  4. What other strategies help me sleep? Answer: Cooler bedroom. Good and dark. Glycine, 500 mg at bedtime. No noise, no nightlight. Precise same time every night. Dim the lights an hour or two earlier. Don't introduce fear into your heart with violent TV just before bed.
  5. Does counting sheep help? Answer: Not to be glib, but yes. You can call it mindfulness, or meditation, or counting......whatever. But there is pretty good evidence that taming your "monkey chatter" by disciplining your brain so a boring, calming, mundane train of thought allows it to then slip into sleep. In the one mile loop in our neighborhood, there are 54 houses on both sides of the road. If I recite them in my head, one by one, I mostly don't make it around the whole loop. You are falling asleep just reading out it.....