Circadian factors in workforce performance

An article published in Neuroscience & Biobehavioral Reviews takes a comprehensive look at the science behind workplace fatigue. In the article, “Fatigue and its Management in the Workplace,” the authors look at the biological causes of fatigue, how the modern workplace affects these biological factors, and some of the effective ways to manage fatigue.

The road to Sochi


With the  2014 Winter Olympic Games quickly approaching, athletes around the world are getting ready to hit the road to Sochi.

The road to Sochi is a long and challenging one, as athletes devote years of training and sacrifice to have a shot at bringing home a gold medal. But for many athletes, the road to Sochi is also literally long and challenging. Take a look at the miles and time zones crossed to get to Sochi:

  • From Calgary, AB Canada – Miles: 5725.4, Time Zone: + 11 hours
  • From Lake Placid, NY USA – Miles: 5137.9, Time Zone: + 9 hours
  • From Leukerbad, Switzerland –  Miles: 1576.6, Time Zone: + 3 hours
  • From Osaka, Japan – Miles: 4887.4, Time Zone: – 5 hours
  • From London, UK – Miles: 1915.4, Time Zone: – 4 hours
  • From Sydney, Australia – Miles: 8784.0, Time Zone: + 7 hours
  • From Buenos Aires, Argentina – Miles: 8186.3, Time Zone: – 7 hours

With all of these miles and times zones to contend with, athletes should probably arrive weeks in advance to adjust to the Olympic setting’s local time, right?

A few weeks ago, we took a look at a recent study, published in the December 2013 Journal of SLEEP, which explored the circadian advantages and disadvantages of NFL teams playing at various times on the East Coast. The study concluded that depending on the start time of the game, there were instances in which the West Coast team was actually at an advantage over the East Coast team, and showed better performance in spite of their travel across time zones. Over the duration of a later East Coast game, the West Coast team’s performance increased 3% while the East Coast team’s performance was diminished by 6% – all because of circadian factors.

When looking at this change in performance in the context of  elite sports, where events can be won by 1/100th of a second, even a small increase or decrease in reaction time can be the difference between a podium or 4th place finish. So does it make sense for athletes to make sure they are settled into Sochi and the local time zone well ahead of the Olympic start? The answer is: There is no simple answer. Depending on time zone changes and timing of athletic event, the opportunity to take advantage of circadian factors will be a little different for everyone.

As we demonstrated in the previous post looking at Circadian Factors in Athletic Performance, Fatigue Science technology can model the change in performance based on all of these inputs so teams or athletes can take measures to optimize performance at the moment it matters.

Sleepy new year!

The new year is quickly approaching and while many of you may have resolutions to improve your health and performance – by working out more or eating healthier – chances are you might be starting off 2014 with a bit of holiday-induced sleep debt. Even if you have spent the holidays getting your required 7-9 hours of sleep, just one late night (a New Year’s Eve party, perhaps) could impact your performance for as long as a week.

While the effects of sleep deprivation on fatigue and performance will be influenced by a number of individual factors, our Fatigue Avoidance Scheduling Tool (FAST) can demonstrate the effect of going to bed at 3 AM and waking up at 7:30 AM, on a previously well-rested person. The chart shows that it will take this individual six nights to recover fully to 100%; If you’re a professional athlete with a game in the first week of 2014, even these small reductions in reaction time could impact your ability to perform your best.





How do you get back on track for 2014? If your new year is going to start out  something like the one in our example, we recommend not performing any safety sensitive tasks on new year’s day and take care for the rest of the week to bank an additional hour or two of sleep every night until you are recovered.

If you are making health a priority for 2014, include proper sleep management in your new year’s resolutions. Happy New Year’s from the team at Fatigue Science!

Circadian factors in athletic performance

A new study published in the December issue of the Journal of Sleep has looked at the impact of circadian factors on athletic performance in NFL football players and concluded that those “playing close to the circadian peak in performance demonstrate a significant athletic advantage over those who are playing at other times.”

The researchers acknowledge that even small variations in performance can mean the difference between winning or losing in professional sports and concludes that applying the knowledge of circadian factors is an underused approach which “is likely to enhance human performance”

Knowing that circadian factors may help your team achieve optimal performance is just part of the equation, how you apply this information is another. Using Readiband to understand a team or athlete’s actual sleep and FAST (Fatigue Avoidance Scheduling Tool) to model game-time performance, trainers and athletes can get the most out of, or more importantly, create their own ‘circadian advantage’.




The study, which is titled: “The Impact of Circadian Misalignment on Athletic Performance in Professional Football Players” was published in the December 2013 Journal of SLEEP. You can view the abstract or download the full study.

What is circadian rhythm?

We often refer to ‘circadian rhythm’ when we talk about the biological needs of our body to sleep. It sounds like a dance move, but it’s actually a science-y thing involving chemicals, hormones, cells and proteins all throughout your body. There are some interesting infographics that try to explain how it works, but we’ll try and simplify it here with words.

Circadian rhythm is defined as a natural cycle of changes the body goes through in a 24 hour period. It’s driven by a number of factors we cannot control, including the rise and fall of the sun.

The circadian rhythm dictates that there are ideal times for our body to sleep, eat, and do activities. The hormonal and chemical changes that your body goes through in it’s circadian rhythm support certain functions that you should be doing during certain phases of a 24 hour period.

Your circadian rhythm controls your:

Sleep / wake cycles – It wants you to wake up in the morning when the sun comes out and go to sleep at night when it’s dark out. As it gets darker out, your brain produces melatonin, which signals that it is time to go to sleep and makes you drowsy.

Digestion – Digestion slows down at night, when our bodies are meant to be resting and doesn’t need the energy generated from food.

Regeneration – Growth hormones increase at night, so your body can repair itself while you sleep.

Energy – Stress hormones rise in the morning when we need to start turning food and oxygen into energy and lowers towards end of day.

Body Temperature – Rises during the day and falls at night. When your temperature drops at night it signals your brain that it is time to go to sleep.

Ever notice that you feel more alert in the summer time when the sun is out longer? Or that you feel bloated if you eat a heavy meal too late in the day? That’s your circadian rhythm in effect.

Based on all these functions we understand that biologically we are programmed to wake up when the sun rises, be active and eat during the day, slow down in the evening, and let our bodies rest and regenerate at night. If you’re not going to bed and sleeping at night, you end up doing things that are out of sync with your circadian rhythm , which is why working night shifts, pulling all-nighters and travelling across time zones can be so disorienting.

Interested in learning more about data-driven fatigue management?

or download our free eBook on the Science of Sleep for industrial workforces

How to eat and sleep this Thanksgiving weekend

With our Vancouver office celebrating the Canadian Thanksgiving weekend, it seemed like a good time to share a few tips to help minimize the impact of weekend activities on your fatigue levels:

If you had a busy work week and only slept six hours a night, you are already heading into the weekend with a sleep deficit. Sleeping in may help reduce the deficit, but may not be enough to allow you to recover from a week of insufficient sleep. A recent study from Penn State University restricted participants sleep to only six hours for a period of five days. On the following two days, the volunteers were permitted to sleep for ten hours. Performance tests were conducted at the start of the study, after the five day period of reduced sleep, and then again at the end. The study concluded that even after two days of sleeping in, the subjects did not fully recover their ability to concentrate, suggesting that “recovery sleep over just a single weekend may not reverse all the effects of sleep lost during the workweek.”

Our advice: Take the extra day this weekend to try and narrow your sleep deficit. Sleep in, take naps, but aim to maintain a schedule of eight hours of nightly sleep next week.

Digestion, much like sleep, is controlled by the body’s circadian rhythm and has it’s own cycle of activity and rest. If you’re planning on enjoying a heavy turkey dinner, plan to serve dinner early. Since digestion naturally slows down at night, heavy and fatty foods consumed late in the evening will be difficult to digest and interfere with your ability to have quality sleep. Research shows that how you eat will also impact your fatigue. Metro UK reports that “adrenaline effectively shuts down digestion” – so if you’re planning to ‘eat and run’ in an effort to make it to various holiday social engagements, you’re shutting down your body’s ability to digest your dinner.

Our advice: Eat early, relax and enjoy a leisurely dinner with your Thanksgiving companions.

It’s nice to enjoy a glass of wine with festive meals but be careful not to overdo it. Too much alcohol disrupts sleep patterns – making it difficult to maintain the deep sleep stage, which is “when the body restores itself“. If you’re not getting deep sleep, you’re going to wake up fatigued no matter how long you stay in bed. It is recommended not to drink alcohol in the last few hours before going to sleep.

Our advice: If you feel thirsty after dinner drink water – just not too much right before bed, and definitely skip the post-dinner coffee.

Turkey often gets the blame for holiday weekend fatigue, but science shows that when and how you eat and sleep, will have an impact on the quality of sleep you get and your fatigue levels heading into the following work week.