Podcast No. 97: How Daylight Savings Affects Your Body

Understanding your circadian rhythm and how to prevent Daylight Savings from throwing your body off.

VP of Performance Kristen Holmes and VP of Data Science and Research Emily Capodilupo return to the WHOOP Podcast for an in-depth look at how the end of Daylight Saving Time messes with your circadian rhythm. This is everything you need to know about how your body’s internal clock can be altered by even just the change of one hour. Emily and Kristen dive deep on the physiology and the science behind it all and share their tips and tricks for how your body can avoid falling behind when we fall back this weekend. Stay healthy and stay in the green!  

Circadian Rhythm & Daylight Savings Podcast Show Notes:

4:37 - Studying the Differences Between Daylight Time and Standard Time. “You see very different physiological impacts and it creates a really interesting case study looking at shifting your clocks by an hour and what the effect is of changing your sleep by an hour.” 5:20 - Daylight Savings Proves Bad for the Heart. A Swedish study found that the rate of heart attacks increases immediately after the daylight savings shift. 6:41 - Understanding Your Circadian Rhythm. “Our bodies have an internal clock that keeps track of days. It’s called our circadian rhythm. It governs, most famously, our sleep-wake cycle. … When your circadian rhythms get thrown off, all of our systems are in this adjustment mode instead of in that nice ‘cruise control’ mode.” 8:22 - Clock Changes and Mental Health. Kristen and Emily discuss the mental and emotional toll changing the clocks can have on us. Kristen points out that emergency room visits related to mental health issues go up following the time change. “That increase is not casual at all,” Emily notes. Kristen and Emily also discuss Seasonal Affective Disorder. 11:39 - Sleep Consistency. Emily highlights 2019 WHOOP research on the importance of sleep consistency, and notes that on average your sleep consistency score on WHOOP takes a 5-point hit when the clocks change for daylight saving time. “We found that changing your sleep consistency by about 5 points has statistically meaningful impacts on sleep efficiency. We expect you to spend more of your time in bed awake. It also decreases REM sleep and slow-wave (deep) sleep. Because of the hit to sleep efficiency, you’re going to get less sleep overall.” 16:01 - Preparing Your Body for Restorative Sleep. “We saw that sleep consistency can explain up to a 36-minute sleep difference in average REM sleep per night, as well as a 15-minute difference in slow-wave sleep per night,” Emily says. “[Sleep consistency] is a behavior. It’s something within our control.” 18:39 - Finding Light. Kristen and Emily discuss how light exposure can help you shake off grogginess. “Try to give your body that sun exposure that says, ‘It’s daytime now.’ It might feel a little bit silly to go stand on your porch and take a couple of deep breaths, but you deserve that minute to ground yourself and expose your circadian rhythm to the sun. It has measurable physiological benefits in terms of aligning the circadian rhythm.” Kristen notes that sun exposure ‘will help you get on track faster,’ and advises people working from home to take advantage and get outdoors if they’re experiencing more flexibility in their workday schedule. 22:23 - Circadian Rhythm and Food. “People tend to think about [the circadian rhythm] as being about sleep. People think about the disruption that daylight savings causes as disrupting sleep, but it’s our whole circadian rhythm. One of the things that I think is somewhat under-appreciated is that the same way that our body tries to produce sleep-promoting hormones when it's anticipating sleep … It’s the same thing with digestion. We anticipate food at certain times throughout the day and we start to produce digestive enzymes in anticipation of receiving that food. If we don’t receive that food, our bodies can feel thrown off. When we fuel at times when our bodies are not anticipating it, because they’re not as ready for that food, we don’t digest it quite as smoothly.” 26:19 - Foods to Boost Vitamin D. Kristen and Emily talk about some of their favorite Vitamin D-rich foods, including fatty fish (salmon, tuna mackerel) dairy products, many breakfast cereals, and tofu. 31:31 - The Sleep Cocktail. Kristen shares a combination of recommended foods for people who need to eat shortly before bed:

• Cottage cheese (1/4-1/2c) is ideal before bed because it includes lots of casein protein, which releases slowly into the body. This ensures a steady supply of amino acids through the night.
• Cherries (1/4-1/2c) are high in serotonin which is a precursor to melatonin.
• Collagen (1-2 scoops) can help accelerate recovery by reducing inflammation & promoting sleep.
• Raw Unfiltered Honey (1 tbsp) taps your liver glycogen before hitting your muscle glycogen (stored sugar in your muscles), so having a little extra sugar before bed can help your brain function better at night and promote sleep.
• Walnuts (1/4 c). Quality fats (short-chain and medium-chain triglycerides) are the perfect energy source to sustain detox and recovery while you sleep.

36:09 - Evening Workouts. Kristen and Emily cite recent research that end-of-day workouts might not be as counterproductive as some have suggested. “[Researchers] showed that exercise before bed, specifically looking at about 90 minutes before bed, did not negatively impact sleep.” 39:22 - Key Takeaways. “To sum this up: The best thing we can do is to establish really clear routines and behaviors associated with sleep-wake timing, light exposure, fueling, and exercise. Those are the big core anchors that the body is going to respond to. Establishing those routines is really going to help our body understand what to expect next.” 39:58 - Prepping for the Time Change. Kristen details how she prepares for the time change. “I start to peel back my time to bed by 10 minutes, which moves my dinner, exercise, everything just ends up getting pushed back just slightly. By the time I hit [2 am on November 1st], I’m pretty well-positioned to manage this change.”