The Deconstructed Dish: Are morning workouts better? 3 Things You Need to Know About Circadian Rhythms

By Jenn Randazzo, MS RD on April 13, 2015 , categorized in Endurance, Strength + Conditioning

Who has time to stay savvy about latest nutrition research these days? Besides, a nutritional breakthrough or wonder food makes headlines every Monday only to be disproved by Tuesday, right?  Even though you may be seconds away from tossing in the kitchen towel and just eating your favorite comfort foods because you’re so frustrated and confused, don’t yet.

Nutrition trends come and go, but I’m here to provide you with evidence-based, sustainable ways to improve your health.  Each month, I’ll focus on a nutritional hot topic, sift through tons of research, separate fact from fiction, and provide realistic solutions to help you improve your life.

I love working out in the morning. Whether it’s 5:00AM or 8:00AM, I’m hitting the pavement (or treadmill if it’s pouring outside) for a solid 40 minutes and enjoying some alone time. Probably, if I’m honest, the most I’ll get for the rest of the day.

If I miss that morning window, it’s so incredibly hard for me to find an alternative time to exercise. Don’t get me wrong: I can make it happened, but it feels so much harder.  To overcome the severe lack of motivation, you can typically see me in the kitchen slamming a shot of Sugar-Free Energizer about 20 minutes before I begin my workout.

Now, cue my sister’s story.  She hates working out in the morning, but every day around 5:00PM, she throws up her hair, laces up her shoes, and energetically hits up her favorite CrossFit or Kaia FIT class.

So, here’s my question: Is it better to exercise in the evening or in the morning? Basically, I’m indirectly asking you, my readers (most of whom I’ve never met), to determine if I am better and wiser that my sister. I know, it’s not fair.

Kidding aside, when should we work out? Does your circadian rhythm, that 24-cycle that helps to regulate our sleep and dietary patterns, influence it at all? If so, how?

Wait, why would my circadian rhythm affect my exercise routine?

Driven by our biological clocks, “Circadian rhythms are physical, mental and behavioral changes that follow a roughly 24-hour cycle, responding primarily to light and darkness in an organism’s environment.1

Circadian rhythms are quite powerful. They can influence a variety of our body’s systems, like sleep-wake cycles, hormone release, and body temperature. When disturbed, the circadian rhythm can increase the risk of a variety of disorders and diseases ranging from insomnia and depression to obesity and diabetes1.

Sifting through the research:

1. Does circadian rhythm determine the best time of day for us to work out?

Although I found a lot of articles that essentially concluded, “some exercise (no matter what time) is better than no exercise” (duh!), I wasn’t satisfied.  After additional digging, I found articles I perceived to be well-done and interesting, despite being done on mice. Here’s one worth specifically noting:

In 2012, researches sought to determine whether scheduled exercise, which happened either in the morning, afternoon, or late evening, influenced circadian rhythm.  After a prolonged period of observation, the findings suggested2:

  • Mice who exercised in the morning or in the afternoon experienced better outcomes (produced more proteins that helped choreograph major organs to sync  with the rest of body in accordance with the biological clock) than mice who remained sedentary.
  • Mice who exercised in the afternoon experienced even better outcomes than those who exercised in the morning.
  • Mice who exercised in the late evening, around 11:00PM, developed significant disruptions in their circadian rhythm2.

2. Can you improve your athletic performance by being in tune with your circadian rhythm?

Many researchers agree that there is a positive correlation between increased body temperature and improved physical performance3.  Too, many researchers who have studied circadian rhythm also agree that typically, our core body temperature is lower in the mornings than it is in the afternoons3.  According to a recent study, investigators examined the effects of the time of day on core temperature and lower body power output in elite rugby players. These players were asked to do the same exercise in the morning and in the afternoon, after both times researchers took their internal temperature. Their findings suggested that their peak power output was significantly higher in the afternoon than it was in the morning; thus, suggesting that their physical performance was better3. In short, waiting until later in the day may allow your body to naturally warm up, resulting in a better athletic performance.

3. Can you actually “fix” or recalibrate your disrupted circadian rhythm by exercising?

Sick of not being able to fall asleep until 2AM despite slipping into your sheets at 9PM? Or, over falling asleep within five minutes of closing your eyes only to wake up at 3AM and not be able to fall back into your REM cycle? Can our circadian rhythms be recalibrated by exercising?

During my review of the research that examined the effect of exercise on circadian rhythm, I found varying recommendations. Some suggested working out at 6:30PM while others recommended closer to midnight (who’s doing that!?). Despite the varying recommendations, most researchers were forced to contend with many variables beyond their control. “In these studies, there have been difficulties in controlling the characteristics of the exercise bout, the athletic status of research participants and exposure to other confounding synchronisers,” suggests a recent study found in the European Journal of Applied Physiology. 4 Because of these methodological complications, it is still unclear if exercise can and does have a significant effect on the recalibration of circadian rhythm.

My Suggestions:

1. Exercise at a time that works best for your schedule, just as long as it’s not too close to your bedtime.

Even though the research suggests that working out in the afternoon may be most aligned with your circadian rhythm, don’t quit your day job just to be able to jet over to the gym at 3:00PM.

  • If you don’t have an exercise routine yet, or your current routine is flexible, try moving your body in the afternoon and see how that feels.
  • If your schedule has you in the office at 8:00AM, or you’ve just been someone who has to get her workout in in the morning, then don’t stop working out just because it’s in the morning.

Bottom line: Exercise in a way that feels good when it best fits with your real-world schedule. Just don’t get your sweat on too close to bedtime. You may actually be disturbing your circadian rhythm, rather than showin’ it some extra love.

2. If you exercise in the morning, incorporate at least a 10-minute warm-up.

To increase your body temperature in the morning, incorporate at least 10 minutes of warming up. Whether it be jumping jacks, or a short jog, move your body in a way that will make your internal temperature rise. Since you’re likely not going to be carrying a thermometer with you (even though I would think you’re a rock star if you did!), use the sweat test. Did you break a slight sweat? If so, you’re ready.

3. To recalibrate your circadian rhythm, exercise.

I know it was a while ago, but did you feel your circadian rhythm off for a couple of days after we “sprung forward?” Or, have you recently jetted off to Europe or Hawaii, only to return home with a mad case of jet lag?

Since the research is still unclear whether exercise can help recalibrate and balance your natural circadian rhythm, try these tips to boost your energy throughout the day and get a deep, restful sleep at night:

  1. Since the circadian rhythm dips generally around 1:00PM to3:00PM, have an energizing snack around 2:00PM or 3:00PM. Try my favorite energizing smoothie made with Vega One: Chocolate Hazelnut Smoothie.
  2. Turn off all electronics at least an hour before bedtime and place them in another room. Because our circadian rhythm can be greatly influenced by light exposure, it’s best to keep those cell phones, tablets and other must-have gadgets away from your face while you sleep. Even that small little green light on your laptop can be causing disruptions in your circadian rhythm.
  3. To help increase melatonin production, that hormone that helps with regulating our sleep cycle, try consuming melatonin-supporting whole foods throughout the day, specifically tart cherries, walnuts, orange bell peppers, tomatoes and flaxseeds.

How are YOU going to live your Best Life by tuning into your circadian rhythm? Share your secrets with me by tagging a photo on Instagram with #BestLifeProject!

bestlifeproject

References
1. Circadian Rhythms Fact Sheet. (2015). National Institute of General Medical Sciences. Accessed on March 13, 2015 from http://www.nigms.nih.gov/Education/Pages/Factsheet_CircadianRhythms.aspx.
2. Schroeder A, et al. (2012). Voluntary scheduled exercise alters diurnal rhythms of behaviour, physiology and gene expression in wild-type and vasoactive intestinal peptide-deficient mice. Journal of Physiology. 590(pt 23): 6213- 3. 6226. Accessed on March 11, 2015 from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3530127/.
3. West D et al. (2014). The Influence of the Time of Day on Core Temperature and Lower Body Power Output in Elite Rugby Union Sevens Players. Journal of Strength and Conditioning Research.  28(6): 1524-1528.
4. Atkinson G et al (2006). Exercise as a synchroniser of human circadian rhythms: an update and discussion of the methodological problems. European Journal of Applied Physiology. 99(4): 331-341.

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Jenn Randazzo, MS RD

Jenn Randazzo works at Vega as a National Educator. She is passionate about building relationships that help people take ownership of their health. As a registered dietitian, she specializes in using client-centered techniques to guide people toward realistic and achievable goals. A strong believer in collaboration, she hopes to change the world through plant-based nutrition.

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