After my last Booze test I wanted to find out the limit of how much alcohol I could drink and have it not impact my Heart Rate Variability (HRV), Muse % Calm score and Glucose level. In a scientific study I had seen that 2 drinks is a limit of what men can drink and have it not effect their HRV. I thought I would give it a whirl by conducting a randomized test.
If I have three alcoholic drinks in an evening does it significantly change my morning HRV and mental calm readings?
What I Did
For twenty days I would either drink three drinks in an evening, or none. To ensure this was a randomized test I used a randomly generated instruction for which days I would drink and which I would not. It made for some funny Tuesday evenings and some less than social Fridays, but science must be served.
How I Did It
I used a Google Spreadsheet to generate a random list of instructions for the twenty day period with an output of “zero” or “three.” Each evening I would either have the drinks or not.
The following morning I would measure my mental calm using Muse EEG headset and my HRV using a Polar H7 heart rate belt that sent data to an app called the Heart Rate Variability Logger. All data went into the same Google spreadsheet.
At the end of the twenty days, I separated the lists into two arrays based on the amount of alcohol and ran a T-Test using the Google Spreadsheet. For days where there was an unusual circumstance (odd food consumption, travel, drinking neither 3 nor 0) I threw out those measurements.
What I Learned
Drinking three drinks in the evening does not significantly affect my HRV, % Calm or Glucose levels the following morning. After separating the data and running the T Test, here were the resulting p values:
For any of the measures to have been significantly impacted the p value would have needed to be .05. So I found a level at which I could have a social drink and not impact my physiology significantly. Anecdotally, on the mornings after 3 drinks mornings I felt fine so my experience matched the results.
I have had enough people ask me how to start doing these studies that I have created a site specifically to help people do these types of N=1 studies. You can get the basic instructions absolutely free and can pay for coaching if you would like. The mission is to support people in taking their own data and testing the dimensions of their own unique physiology.