For access to all of our training, gear, and race coverage, plus exclusive training plans, FinisherPix photos, event discounts, and GPS apps, sign up for Outside+.
When Jan. 1 rolls around, we are often full of good intentions in our bid to be better, fitter, healthier humans. One goal that seems to be remarkably common, especially this year, is Dry January. After several weeks of excessive alcohol consumption over the holidays, giving up booze for the first month of the year is often considered a great way to reset, detox, and kickstart your year. This could be particularly true in 2021 with statistics from the first lockdown in the U.S. showing a 54% increase in alcohol sales. In my native Australia, one study found one in five people reported increased alcohol intake during lockdown.
While I won’t be partaking in Dry January this year, I did complete a month of no drinking back in October. The goal was a month of zero alcohol for no reason other than wanting to challenge myself after lockdown. What I did not realize was the impact it would have on several parameters of health that I had been tracking with my Oura ring for several months prior. I was remarkably surprised to see just how much it affected my training, performance, sleep, recovery, energy levels, and mental clarity. For those of you aiming to complete Dry January—and for those of you who might be on the fence—keep reading to see the benefits it can reap. Some of this data might help keep you on the wagon a little longer!
Resting Heart Rate
Resting heart rate is a good indicator of overall health and, typically, a lower resting heart rate is better and a good indication of cardiovascular health. During the months leading up to October, my resting heart rate was steady, averaging 42-43 bpm. Throughout October, there was a noticeable reduction in resting heart rate with the average for the month being 39 bpm. Depending on that day’s exercise volume and intensity there were days when it was consistently 36 bpm. This came as a surprise to see such a steady drop in heart rate.
What was more of a surprise was that in the month of November, as I began to resume drinking alcohol, my average resting heart rate bounced back to 42 bpm. While the amount being consumed was certainly not large (and usually restricted to a Friday or Saturday evening), this is still some significant extra work for the heart, which, when you extrapolate out over the course of a year equates to 1,576,800 extra beats per minute. That’s a lot of extra workload for the heart.
HRV (heart rate variability) is the measure of the fluctuations of the heart, beat to beat, (or R to R intervals) to assess cardiac autonomic nervous system (ANS) regulation. As such, HRV represents the ability of the heart to respond to a variety of physiological and environmental stresses and stimuli. It is proposed as a measure of recovery and ability to cope with stress (mental and physical) imposed on the body. A low HRV may reflect the body’s inability to cope with internal and external stressors. It is not universally agreed upon in terms of its importance due to limitations in the literature, yet it is agreed that HRV is impacted by stress and therefore can be used as one objective marker to quantify stress on the body.
As you can see from the two graphs below, my HRV peaked during the month of October when no alcohol was being ingested and actually had a sharp drop off once I recommenced drinking in November. You can also see the direct impact, much like the impact on resting heart rate, although it is an inverse of that relationship, with HRV dropping sharply to reflect very little beat to beat variation.
Probably the most disturbing insight into acute alcohol consumption was its effect on my resting heart rate overnight when overconsumption occurred. The following graph was after a Saturday evening out with friends. The evening involved drinking and eating at an event (beer and wine were consumed along with food). Estimated consumption was in the region of five or six beers and a bottle of wine, which is obviously above the recommended amount of alcohol. This intake resulted in a 27% increase in resting heart rate, which is considerable. When you look at that alongside the sleep data and the HRV data too, it becomes very clear that (excessive) alcohol is not a tonic you want to be reaching for on a regular basis
Alcohol’s Impact on Sleep
Alcohol consumption is a universal health behavior that is associated with poor sleep. It will cause a dose-dependent effect on heart function due to its impact on the automatic nervous system (ANS), along with disturbing recovery, sleep ability, and stages of sleep. Poor sleep will also have a negative effect on the ANS and this will impair regenerative processes, recovery from training, metabolic homeostasis and be associated with poor health outcomes.
While singular metrics do not provide much insight and certainly singular points in time provide little insight, tracking over the longer term (with a tracker such as the Oura ring) is great as you can see constant data in a simple to digest format and start to learn the impact that certain aspects of life can have on what it is recording. With alcohol intake, for example, I could see how a chicken/egg scenario begins to develop: alcohol results in poor sleep which leads to fatigue and can increase the likelihood of reaching for a glass of wine or two the following day to help relax without fully appreciating that this is only serving to perpetuate the problem. The best solution for a truly restful night’s sleep? Avoid alcohol altogether.
As interesting as it is to view statistics that reveal apparent improvements in health, I would also argue that some of the anecdotal findings are worth discussing as well. During the month of October my training was considerably better and more consistent, with a minimum of 60 minutes training every day and often two workouts a day. This may not sound like much (especially to triathletes), but the intensity of the sessions was consistently high (HIIT and strength work, primarily) to maximize the benefits from minimal training duration.
Increased energy levels were the other noticeable difference: I was able to jump out of bed with a far greater degree of energy, as well as enhanced clarity of thought and processing. I do believe that even with a small reduction of alcohol over a small period of time that my mental clarity, thought processing, and decision-making improved significantly.
Contrary to my previously held opinions, I do not believe alcohol has any place in a program designed to maximize health and performance. While there are some arguments for how red wine can have health benefits, I actually found it to have the biggest negative impact on my sleep quality and duration, HRV, and resting heart rate. I have not drunk red wine since.
There are obviously other factors to take into consideration when it comes to alcohol intake. For those truly looking to maximize training, health, performance, and sleep, I cannot advocate for it. But for many of us (me included), I can tolerate drops in some metrics and still enjoy alcohol in a social setting. That said, this experiment has led me to reduce my overall alcohol intake and I plan on a three-month spell of abstinence to further assess the impact. While alcohol can be enjoyed in moderation—and it often plays a big part in many aspects of our cultural and social lives—its wider impact, especially when consumed in excess, can have far-reaching implications. If you are interested in reducing or eliminating alcohol with a view to better health and fitness, I urge you to experiment—and, like me, you’ll likely be incredibly surprised by the results.
Scott Tindal is a performance nutrition coach with 20 years of experience working with pro and amateur athletes. He has a Masters degree in sports medicine and a post-graduate diploma in performance nutrition. He is the co-founder of FuelIn, an app-based personalized nutrition coaching program.