Sleep & Circadian Rhythms – 6-Tips from World-Experts

Sleep is fundamental to human health and performance.

Over the last decade, the research on sleep and athletic performance has exploded, highlighting the dramatic impact of sufficient rest on an athlete’s ability to train, recover and perform. 

Talk to any strength and conditioning coach and they’ll likely say, ‘for sure, I focus on sleep’. Talk to any nutritionist or practitioner and you’ll probably hear ‘yep, I emphasize sleep with my athletes’. Talk to any athlete and they’ll say ‘yep, I know sleep is important’.

Today, everyone ‘knows’ sleep is good for athletic performance but here is the uncomfortable truth; athletes still aren’t getting enough sleep!

Are Athletes Getting Enough Sleep?

Despite all the science, social media coverage and focus in high performance and clinical circles, athletes are still struggling to achieve sleep recommendations. 

In fact, the research shows athletes are remarkably poor at rating their own sleep quantity and quality. 

In elite national-level athletes, recent study of over 800 participants found 75% were not getting 8 hours of sleep per night, and more alarmingly, 11% were not even getting 6 hours of sleep nightly.(1)

What about Olympic-level athletes? Surely, they optimize sleep to support optimal recovery and performance? Not quite. Olympic athletes consistently show poorer sleep quality and more fragmented sleep than age and sex-matched controls.(2)

Why do athletes still struggle with sleep? Athletes are people too. Balancing training, work commitments, family and personal life takes up a lot of time in the day. Unfortunately, sleep gets the short end of the stick. 

It’s not just athletes. The general population averages 6.5 hours of sleep per night, below the National Sleep Foundations recommendation of 7-9 hours nightly.(3) Even more troubling, 30% of the population gets less than 6 hours of sleep per night. 

The trickle-down effect on health and performance are profound. If you don’t get enough sleep, your physical output is impaired (e.g. sprint speed, reaction time, etc.), sport-specific skill (e.g. three-point shooting, first-serve accuracy), immunity (e.g. more colds and flu), cognition (e.g. memory, executive function, etc.) not to mention how it impacts your overall health (e.g. increased risk of virtually all chronic disease conditions.)

It’s no longer about raising awareness of inadequate sleep time and quality, but rather, actually getting athletes to implement the strategies!

(It would be great if we, as humans, made decision based purely on logic, but as expert sport psychologist Dr. Peter Jensen PhD points out, it’s not usually the case).

Sleep & Circadian Rhythms - 6 Tips from World-Experts

I’ve had the privilege of interviewing some of the top sleep experts in the world. Here is a quick glimpse into some of their strategies for supporting sleep and circadian rhythms in athletes. 

1)    Set Your Schedule – Sleep Timing

In training, consistency is crucial for achieving success. The same is true for sleep. Dr. Amy Bender, PhD of the Canadian Sport Institute – Calgary emphasizes the importance setting your morning wake time and evening bedtime.  

For athletes, this can be very difficult. Early morning exercise, two-a-day training, and late-night sessions or competitions (not to mention media, work, or school commitments) make it difficult for a lot of athletes to get into a consistent sleep schedule for an extended period of time. Inevitably, this leads to inadequate total sleep time and compromises sleep quality.

Get back to the fundamentals; be consistent with your sleep and wake times. The more you stick to a routine, the more impact you’ll see in the gym and on the field.  

2)    Circadian Rhythms & Weight Gain

When you eat has a big impact on your circadian rhythms and therefore sleep. In my recent interview with Dr. Dan Pardi, PhD he highlighted some important recent research in this area, comparing how night time eating impacted weight gain in mice. In the study, one group of mice were fed their normal meals during the day, while the other group received all of their meals at night (when they would normally sleep). Total caloric intake and physical activity were controlled and exactly the same in both groups.

What happened?  The mice who were fed all of their daily calories during the night - when they would typically be asleep - gained significantly more weight compared to the control group eating during the day. What’s the lesson? Food intake has a significant impact on your circadian rhythms, therefore avoid eating too late at night if you’re looking to keep body composition (and health) on point.

3)    Don’t Be Stupid – Caffeine & Athletes

Physically demanding sports require a special amount of effort and intensity. Not surprisingly, American football, hockey, and rugby players often turn to caffeine and pre-workouts for an added boost. 

Dr. Ian Dunican PhD, recently completed a study in Super Rugby players in Australia and found many athletes were unaware of the amount of caffeine contained in their pre-workout supplement. (In fact, some didn’t even realize it contained caffeine!) 

Too much total caffeine and too much caffeine late in the day can both compromise your sleep total and quality. 

If you’re pushing the caffeine limits hard on game day, make sure to balance your short-term goals (i.e. game day) with your long-term goals of  recovery and health throughout the season. A good heuristic – or simple rule – is for athletes not to exceed 6mg/kg/day of total caffeine and to limit intake in the afternoon.

4)    Morning Larks & Night Owls - Athlete Chronotypes

During pre-season training camp or when you travel on a road trip with your team an important consideration that often gets overlooked by coaches and performance staff is athlete chronotype. In the research, morning larks are defined as early-risers while night owls naturally prefer to stay up later.  

Dr. Michele Lastella, PhD has examined the effects of athlete chronotype on performance and found some emerging evidence on performance and recovery. A recent study found baseball players who were morning larks had significantly higher batting averages in day games.

In practice, an important take home message for coaches is to carefully consider whom they pair together as roommates; combining morning larks with night owls could lead to more disturbed sleep for both and compromise recovery (and ultimately performance).

5)    Can You Make Up A Sleep Debt? Memory, Executive Function & Sleep

It’s not just physical performance that is impaired from lack of sleep, mental performance also takes a big hit. Dr. Norah Simpson, PhD from Stanford Medical School recently found in her study on sleep and performance that 17-19 hours of wakefulness significantly compromised your cognitive performance (and the equivalent to having a blood alcohol level past the legal limit!

Does this mean you can simply catch up on sleep on the weekend after not sleeping enough through the week? Unfortunately, Dr. Simpson’s work says no. 

You need to be consistent on a night to night basis to reap the full benefits of total sleep. If you don’t get enough sleep at night, it will compromise memory, attention and executive function. In short, your brain game will suffer (important on the playing field or the boardroom). 

6)    The Nappucino – Pros & Cons

If you’re seriously running low on sleep, but still need to be sharp and perform, the coffee nap or ‘nappucino’ has become a popular new strategy to support cognitive performance after an afternoon nap. 

Why has this become so popular? A recent study found having a small coffee before your nap (e.g. coffee + nap) outperformed having a coffee or having a nap, respectively.(4)

How does it work? Dr. Cheri Mah, MD, sleep expert and consultant to professional sports teams, explains it takes approximately 15-minutes for caffeine to begin to exert its effects in the body. As such, after you wake up from your 20-minute nap your mental acuity gets a small boost from the power nap (increasing alpha-brain wave activity) as well as an additional boost from the pre-nap caffeine hit. 

Of course, Dr. Mah warns you need to be sleep-deprived for this to be truly effective. What qualifies as sleep-deprived? You must feel so fatigue you could fall asleep within five minutes. If that sounds like you, Dr. Mah finds it’s a great tool to keep cognitive performance running on all cylinders.

The Bottom Line

Sleep is a key pillar for recovery. Get back to the fundamentals and figure out how to best apply them in your setting, with your athletes, for long-term success.

Strength coaches aren’t looking for ‘new’ exercises to train and develop athletes; they have the tools already, it’s simply a matter of fine-tuning them. 

The same mentality should be applied to supporting improve sleep time and quality. You don’t need any ‘new’ strategies (or tech), you just need to figure out what evidence-based strategies your athlete will actually implement. It takes time, it takes experimentation, and it takes willingness on the part of both athlete and practitioner. 

Implement some of the fundamentals from the 6 world-experts in sleep science discussed in this article, or listen to more in-depth discussion in Season 3, Episode #9 of the Dr. Bubbs Performance Podcast).

Knowing you need more sleep is the first step, but in and of itself, rarely leads to behavior change.  Take the time to uncover what will inspire and motivate your client or athlete to take action and keep your focus on sleep fundamentals for long-term success.

 

Dr. Marc Bubbs, ND, MS(c), CISSN, CSCS

 

Want to learn more? Take a deep-dive into sleep and circadian science in Chapter 1 of my new book PEAK – The New Science of Athletic Performance That Is Revolutionizing Sport.

Pre-order on amazon and get free bonus material… as well as a chance to win prize packs, 1-1 visits with dr. bubbs or a talk for your gym or facility1

Pre-order on amazon and get free bonus material… as well as a chance to win prize packs, 1-1 visits with dr. bubbs or a talk for your gym or facility1

Question about sleep and circadian rhythms? Leave it in the comments section below…

7 (Evidence-Based) Reasons To Take More Naps

Today, over 33 percent of America gets less than 6 hours of sleep, which throws your blood sugar and insulin levels out of whack, ramps up cravings, and shoots your cortisol stress levels through the roof. No wonder you’re tired.

One of the most common complaints from clients is fatigue. Practicing in a busy downtown clinic in a major city means I see a lot of Type A clients constantly on the go from work and play.

Whether it’s trouble getting out of bed in the morning without hitting snooze three times, struggling through afternoon energy crashes or not getting to bed early enough, sleep has a major impact on mental and physical health (and performance).

We sleep less than our grandparents’ generation, and we’re constantly stimulated by connectivity. We’re overtaxed!

The average person today gets 1.5-2.0 hours less sleep than our grandparents’ generation, and when you combine that with the constant stimulation of mobile devices and connectivity, our brains and bodies are generally overtaxed and under-recovered. (1) Before you add more “siestas” into your day, you need to understand how sleep works to maximize your naps.

What Is a Sleep Cycle?

There are two main types of sleep: rapid eye movement (REM) and non-rapid eye movement (non-REM), which are separated into four stages. You can think of REM as “active” sleep and non-REM as “quiet” sleep.

In Stage 1 (non-REM), you’re settling down to rest and you drift in and out of sleep. This period lasts 5-10 minutes, during which the brain produces theta waves that slow brain activity. It’s the period between wakefulness and sleep. (If someone woke you up at this point, you would probably say you weren’t even asleep.)

In Stage 2 (non-REM), your body temperature drops and your heart and breath rate become more regular. Ironically, your brain produces small bursts of activity in preparation for deeper sleep phases. You spend about 20 minutes in this phase.

Stage 3 (non-REM) is when slow delta brain waves kick in, your muscles relax, blood pressure drops, and you transition from light to deep sleep. This is your deepest sleep, when your body really starts repairing and rebuilding your muscles, memory, immunity, hormones, nervous system, etc. It’s like taking your car into the mechanic: deep sleep tunes-up the body so it’s running on all cylinders.

Stage 3 sleep is the deepest, restoring your body’s muscles, memory and immune system.

In Stage 4, you enter REM sleep and your body becomes extremely relaxed (in fact, paralyzed) and your brain more active. Rapid eye movement begins in this stage (thus the REM acronym), as well as your dreams. Most people spend about 20% of their sleep in REM.

Your body rolls through all of these stages every 90 minutes, but they don’t happen in sequence. You start off in stage 1, then progress to stages 2 and 3 before your body reverts back into stage 2. This cycle occurs multiple times before you hit REM sleep, about every 90 minutes.

Benefits of Napping

Adding naps into your routine can provide numerous health benefits. Remember, a nap is usually only light sleep (20-60 minutes in phase 1-3) or one sleep cycle (90 minutes), whereas in deep sleep overnight, your body will roll through multiple cycles. Check out the of benefits of napping below:

1. Naps Improve Brain Function

Napping is the ultimate brain-hack. Research shows even a 5-15 minute nap can significantly improve cognitive function for the next 1-3 hours, something most of us can really use during that afternoon slump. (2)

2. Naps Prevent Weight Gain

If you don’t get enough sleep time at night, you’re over 50% more likely to be obese. (3) That’s no joke. If you know you aren’t getting to bed early enough at night, make time to decompress during the day to maintain a healthy body composition. The extra sleep and recovery from a midday nap can help mitigate these effects.

3. Naps Support Athletic Performance

Not getting enough sleep is also a performance killer. The American Academy of Sleep Medicine recently found that sleep restriction reduced maximal aerobic power, energy expenditure and time to exhaustion in athletes. (4) It’s no wonder elite athletes nap so often!

4. Naps Improve Immune Defenses

If you get less than six hours of sleep nightly, you’re at 4.5x greater risk of catching a cold or flu. (5) This is one of the reasons why you get sick when you’re trying to hit a deadline and burning the midnight oil (at the expense of sleep) or when you’re a new parent who is constantly waking up throughout the night to comfort or feed your baby. Napping can help offset this effect and increase immune function.

5. Naps Can Boost Your Memory

Pre-school kids do this as part of their daily routine, and now the research shows it helps to improve memory consolidation. That’s right, a 30-minute nap within four hours of a learning task significantly improves memory; increasing this to 45-60 minutes for adults could make your memory five times more effective. (6) We always think doing “more” is the answer, but this research highlights that taking the time to rest will increase your efficiency.

6. Naps Improve Resiliency from Travel

If you travel for work and fly across multiple time zones, it deeply impacts your body’s circadian hormone output, significantly raising cortisol and adrenaline stress hormones and reducing sleep quality. (7) Naps help build resiliency by increasing the amount of time you spend in parasympathetic “rest and digest” mode.

7. Naps Lower Blood Pressure

If you’re always on the go, regularly drinking caffeine, or in poor health, you may have high blood pressure. Studies show that taking a regular afternoon nap is inversely associated with heart attacks. (8) Another great reason to make time for a siesta.

How Long Should You Nap?

Your body runs on a 24-hour biological clock, known as your circadian rhythm. This rhythm peaks in the morning (to wake you up) and falls in the evening (to prepare you for sleep). It also bottoms out a little in the afternoon, one of the reasons we all feel a little fatigue around then. During this 24-hour cycle, we have two periods of intense dips: one between 2am to 4am, and the other approximately 10 hours later. If you wake up earlier, this afternoon dip will be more towards 1-2pm, while if you start your day a bit later, it may be anytime between 2-4 pm. It’s important not to nap too close to bedtime, as this will shift your circadian rhythm and you’ll struggle to fall asleep.

The early afternoon is the best time to nap. If you sleep too close to bedtime, it’ll shift your circadian rhythm.

The duration and timing of your nap are important factors to consider. If the timing of your nap is off, you’ll likely wake up tired, groggy and disoriented (not the effects you were likely aiming for). Below are three napping strategies that can help boost your mental and physical performance. Use the one that works best for you.

The Desk Worker’s Nap

If you work at a desk all day, it’s not easy to carve out 60 or 90 minutes to nap during the day. The “desk worker’s” nap is only 15-20 minutes in stage 2 sleep, but helps to quickly recharge your brain to boost cognitive function. Aim for anytime between 2pm and 4pm.

The Entrepreneur’s Nap

If you work for yourself or set your own hours, it’s possible to carve out a longer stretch for napping during the day. Business owners usually work really long days, so getting a full 60 minutes allows you to get into stage 3 sleep and consolidate better memory. Again, aim for between 2pm and 4pm.

The Athlete’s Nap

If you’re training intensely, your body will benefit from a full 90-minute sleep cycle (with REM sleep) to maximize recovery from training. This type of sleep enhances nervous system and muscular repair, as well as boosting creativity (for the artist types who want to take advantage too!). Athletes normally perform two-a-day training, so the nap may be a bit earlier, between 1pm and 2pm, to allow time before the afternoon training session.

We are busier today that we’ve ever been, and sleep usually takes a back seat when you’re pressed for time. Reboot your mental and physical performance by adding a daily nap into your routine. It’s an incredible health hack that can supercharge your brain and body so they can keep up with your hectic pace.

Dr. Marc Bubbs ND, CISSN, CSCS

 

Want to learn more? Listen Dr. Amy Bender PhD talk naps and sleep on the Dr. Bubbs Performance Podcast...

How Big Is Your Sleep Debt?

In the Paleolithic or ‘hunter gatherer’ era, from 2.6 million years ago until the agricultural revolution 10,000 years ago, our ancestors woke up with the rising sun in the morning and rested for a good nights sleep not long after sundown.  Scientists estimate that our Paleolithic ancestors averaged about 10 hours of sleep per night.  Of course the absence of an external light source, television sets, and laptops  made it a little easier to get to bed so early, but the benefits are deeply engrained in our DNA.  

Your circadian rhythms are based on the light and dark cycles of the day and have a profound effect on your bodyweight, cardiovascular health, fertility, and well-being. Melatonin, your body’s sleep hormone, is secreted in the evening about 3 hours after your last meal.  It makes you feel tired, drowsy, and prepares you for deep rejuvenating sleep. 

In winter, Paleolithic people slept longer hours – approximately 10-12hrs per night – as the days got shorter and darker.  Your immune and hormonal functions are linked to these evolutionary circadian rhythms of light and dark, and understanding how this effects you will help you improve your energy levels, build muscle, burn fat, and upgrade your overall health.

For example, daylight increases your dopamine and cortisol output, getting you out of bed and ready for the day ahead.  When was the last time you felt energized in the morning? How many cups of coffee do you go through to get yourself going in the morning? Do you need your alarm clock to wake up or do you wake up naturally? 

Your natural hormonal patterns shift throughout the day and by nightfall your cortisol and dopamine levels should be at their lowest, allowing melatonin production to kick in and stimulate your repair and rejuvenation hormone... growth hormone.  Growth hormone is essential for rebuilding your body while you sleep, helping to build lean muscle, burn fat and keep your immune system strong.  (Your body is hard at work while you rest!)

So what’s the problem with our 21st century sleep patterns?

Two generations ago, our grandparents average about 9-10 hours sleep per night, not very far off our Paleolithic ancestors.  Today, the average North American gets between 6-7.5 hours of sleep, about an hour or two less than the recommended 8 to 8.5 hours sleep per night.  Over the course of a year, this would amount to approximately a 500-hour ‘sleep debt’! 

Over-consuming coffee can add to the problem. How do you know if you are over-doing the stimulants?

You’ve been abusing your coffee intake if you don't feel the same ‘kick’ from your morning cup of joe, or if stopping your intake results in   headaches, irritability, or intense fatigue.  Coffee triggers the production of adrenaline from the adrenal glands and stimulates our sympathetic – ‘fight or flight’ – nervous system.  While this is okay in moderation, chronically relying on this form of energy is like revving the RPM’s on your car constantly into the red zone. Before too long, you'll burn out your engine!

So what can you do to start cutting into your sleep debt? 

Let’s start in the bedroom.  The key to sleep is ensuring you have total darkness in your bedroom.  Make sure to remove all light sources (think red lights from the alarm clocks), cell phones on the bedside table, and nearby laptops from the vicinity of your head. All of these stimulate the nervous system and prevent deep sleep.  Next, turn off the television or shut off your laptop at least an hour before bed to allow your body to unwind.  All of these stimulants activate the nervous system and prevent deep sleep.  Finally, get to bed before midnight to increase your number of sleep hours per night. In Tradtional Chinese Medicine (TCM), every hour of sleep before midnight counts as DOUBLE, because they are so valuable for restoring health and wellness.

Make time to 'schedule' in more sleep... it will pay off with better energy, productivity, and performance at work and in the gym!

Dr Marc Bubbs ND, CISSN, CSCS

 

Check out more articles in the SLEEP SERIES...

References:

  1. Sabanayagam C, Shankar A.  Sleep duration and cardiovascular disease: results from the National Health Interview Survey.  Sleep.2010 Aug;33(8):1037-42.
  2. Alvarez GG, Ayas NT.  The impact of daily sleep duration on health: a review of the literature.  Prog Cardiovasc Nurs. 2004 Spring;19(2):56-9.
  3. Ayas NT, White DP, et al. A prospective study of self-reported sleep duration and incident diabetes in women. Diabetes Care. 2003 Feb;26(2):380-4.
  4. Chaput JP, Després JP, Bouchard C, Tremblay A.  Association of sleep duration with type 2 diabetes and impaired glucose tolerance.  Diabetologia. 2007 Nov;50(11):2298-304. Epub 2007 Aug 24.
  5. Vgontzas AN, Bixler EO, et al. Chronic insomnia is associated with nyctohemeral activation of the hypothalamic-pituitary-adrenal axis: clinical implications. J Clin Endocrinol Metab. 2001 Aug;86(8):3787-94.
  6. Kobayashi D, Takahashi O, , et al. Association between weight gain, obesity, and sleep duration: a large-scale 3-year cohort study.  Sleep Breath. 2011 Sep 3. [Epub ahead of print]