With over four hundred billion cups of coffee consumed each year, caffeine is by far the world’s most widely-consumed psychoactive drug. For many of us, a hot cup of coffee proves to be a powerful and potent stimulant — a necessity to start the day. But caffeine’s effects vary significantly from person to person, and its actual effects on productivity remains unclear. Beyond anecdotal evidence, numerous studies show that, in small doses, caffeine provides an increase in energy and alertness, while improving reaction time and cognitive performance. But is coffee really making you more productive?
What does the research say?
The effects of caffeine on productivity have been a topic of considerable academic interest — researchers at Johns Hopkins University recently found that consuming small amount of caffeine can have a positive effect on long-term memory. In a double-blind trial, participants were given either a 200-milligram caffeine tablet or a placebo, and were asked to study a series of images. The next day, both groups were shown a new set of images, including pictures that were visually similar to the previous — the caffeine group was better able to identify these new images as “similar” rather than citing them as the “same.” In a paper published in Nature Neuroscience, the researchers wrote that this ability to recognize the difference between similar but not identical items — called “pattern separation” — suggests that the caffeine group benefited from greater memory retention.
However, other research suggests that many of the benefits of caffeine can be replicated by placebo. In another double-blind study at the University of East London, participants were randomly given either caffeinated or decaffeinated coffee — half were told they were regular coffee, and half that they were given decaf, also at random. Interestingly, the participants who were told that they received caffeinated coffee performed better on tests measuring reaction time, self-control, and reward motivation. The researchers concluded that the relationship between caffeine consumption, mood, and performance depends on many individual psychological variables — strangely, all participants in the study reported increased feelings of depression after drinking coffee, although this increase was slightly lower in the group that received caffeine.
Research also shows that caffeine also has a complex effect on creativity. Maria Konnikova observed in The New Yorker that “creative insights and imaginative solutions often occur when we stop working on a particular problem and let our mind move on to something unrelated.” As evidence, she pointed to a 2012 study in which participants performed better in creative thinking exercises (for example, devising novel and inventive uses for an everyday object like a newspaper) after they had allowed their mind to “wander” by switching between “undemanding,” low-intensity tasks. This suggests that caffeine may assist more in very simple, repetitive tasks like checking e-mails or filling out forms, and less in jobs that require high levels of insight and creative thinking.
And, for the same reasons caffeine increases alertness and wakefulness, it also has a tendency to cause anxiety, jitteriness, and sleeplessness. Scientists at Rice University studied the effects of caffeine on sleep — they observed that a typical cup of coffee decreased the average sleep time of study participants by an average of two hours; it also increased the amount of time it took to fall asleep by thirty percent. Coffee also had significant effects on quality of sleep: the number of sleep awakenings in the experiment subjects doubled. These conclusions has been reproduced in numerous studies, and suggest a significant risk of impairing your creativity and productivity if you don’t properly manage your caffeine intake.
Many people don’t know that the human body naturally “caffeinates” itself with the hormone cortisol at specific times of day, depending on your body’s natural circadian rhythm — typically early in the morning (between 8am and 9am), around lunch time (between 12pm and 1pm), and once again in the late afternoon (from 530pm to 630pm). If you are an avid coffee drinker, you may be impairing your body’s ability to produce cortisol — by drinking coffee when it’s not needed, i.e. when your body is attempting to naturally energize itself according to its hormonal cycles, you may build a faster tolerance to it.
Test it for yourself!
All the research shows a complex interaction between caffeine and bodily cycles — so instead of relying on the abstract conclusions of large-scale studies, how can you determine the specific effects caffeine has on your body? Caffeine’s effects depends on dosage, body type, weight, age, time of day, and many other factors; so it’s best to monitor all these variables by collecting your own data. First, you need to make sure you’re collecting accurate information: here are some tools we recommend.
RescueTime records how much time you spend using computer applications and browsing web sites. It allows you to keep track of how you are spending every minute of the day, and when and how you are wasting time, and it doesn’t require any effort to set up! It simply runs in the background and stays on top of your browsing habits for you.
Jawbone UP Coffee
Jawbone UP Coffee is a great app for tracking your coffee intake — it’s a simple tool for logging your coffee, tea, and energy drink consumption, to see how it changes overtime.
Sherbit is a personal dashboard that gives you access and control of your personal data in one place. The app syncs with over twenty-five applications including Facebook, Fitbit, Uber and Withings to gather and visualize data. From there, you can identify patterns in your daily habits and correlations across multiple services. For example, if you wanted to find out if you were less active on days you worked more, you could add steps counted by your Fitbit and productivity hours tracked by RescueTime. Download Sherbit from the the App Store here.
Here are some results from our own test:
By combining the data from Jawbone UP and RescueTime, I found a correlation between caffeine and productivity. You can see this by looking at the trend lines and flipping between the tabs at the top of the chart.
However, I found an even stronger correlation with my sleep and productivity — the more coffee I drank, the less sleep I got. This seem to be true for everyday other than JuIy 22nd and July 29th, but as I looked closer I realized that I had consumed coffee earlier in the morning on those days. This may seem like an obvious conclusion in retrospect, but being able to visualize the data made the effects of coffee on my life much more apparent to me. By reflecting on my data, I realized that there’s is a dual effect on the relationship between coffee and sleep: caffeine affects my quality of sleep and reduces the length of time I’m awake… however, when I don’t get much sleep the previous night, I tend to drink more coffee the next day, perpetuating the cycle. I also noticed that my quality of sleep decreases much more significantly when I drink coffee late in the afternoon — I realized that caffeine tends to work best early in the morning, when it will have a minimal effect on my sleep that night.
Have you found interesting correlations between different data sources? Let us know in the comments below.
I love the word balance. It implies that you have enough of everything. You’re not wanting for anything, or drowning in anything. When we talk about work/life balance, it means you’re getting enough work done, but you’re also spending enough time resting, relaxing, and attending to your family, hobbies, and interests outside work.
For those of us whose work tends to blend into our lives it’s even more important to find this balance. For my co-founder Josh and I, we find ourselves working in some form or another every single day. Which means if we’re not working we tend to feel a nagging sensation that we should be, because it’s become our default state.
Not to mention the ever-growing mountain of side projects and volunteer activities we want to take on, and new skills we want to learn.
I’ve always been keen to fill up every day with learning and practising new skills, but I’ve never been great at making sure I get enough exercise. Maybe you have a particular area of work or life that gets neglected. My ongoing imbalance was the impetus for me to start tracking my activity and other areas of my life.
I started out with a simple activity tracker on my phone, and graduated to wearing a Fitbit all day, every day. I use apps like RescueTime to track what I do each day, and put as much of this data into Exist as I can.
Exist is designed to help you find meaning in the data you track. There are three big reasons it’s helpful for finding that balance between work and “life” activities: it uncovers hidden correlations and trends, it has built-in mood tracking, and it creates personalised goals based on your data.
Tracking data about my own activities causes me to ask myself questions like “Am I improving?” and “Have I been doing x more or less this month?”. Exist helps me answer these questions by surfacing insights into my data. For example, I recently had this insight on my dashboard:
Walking less this week
8,545 average steps, 1% decrease
Walking less isn’t something I want to make a habit of, but thankfully I only dropped by 1% in the past week. And knowing that my overall average steps is around 8,000 per day, I’m pretty happy with that average from last week.
I also noticed these sleep-related insights recently:
For some people, going to bed later and getting less sleep would be a bad thing but those sleep numbers are pretty good for me. I have a tendency to oversleep some days, just because I don’t have a set time I have to start work, and it tends to set my day up badly. Knowing this, I’m putting in a conscious effort to not stay in bed too long in the mornings, and these insights show that it’s working.
Seeing what my average is for each type of data can be illuminating, too. Exist breaks down averages by day of the week, as well as showing my overall average for each data point.
(Note: I used a Jawbone UP between my Fitbit Force breaking and the Fitbit Charge being released, which doesn’t track floors. I haven’t been wearing my Fitbit Charge long enough to increase my floors average yet)
It’s good to see, for instance, that my average mood is 4/5. It’s also pretty obvious, looking at this chart, that I tend to rate my mood higher on weekends.
I can also see that I tend to walk more on Fridays, and that my average steps is just over 8,000 per day.
My productivity tends to dip on weekends, and jumps up most on Tuesdays and Wednesdays. This makes sense, since Monday is our catch up day at Hello Code, so Tuesday is when I start to really get stuck into my work for the week.
I like knowing these averages, because it helps me calibrate my own goals. If you’ve ever used a fitness tracker or a pedometer app on your phone, you’ve probably been confronted with a suggested (or enforced) 10,000 steps per day goal. Although this might be suggested as a healthy amount of exercise for adults, it’s ridiculous to expect someone who walks 3,000 steps per day on average to suddenly jump up to 10,000.
8,000 steps per day has been my average for the past six months or so. I know this is the amount of exercise I get without trying too hard, so if I want to increase my activity levels I’ll know to start by aiming for around 8,500 steps.
Seeing the correlations between different data points is one of the most surprising and useful parts of Exist. Although correlation doesn’t imply causation (i.e. just because two things are related doesn’t mean one causes the other), correlations can still give us useful clues into our existing behaviour and how different things affect us.
I’m especially interested in what affects my productivity (tracked with RescueTime) – both negatively and positively. I’d like to learn from my correlations so I can set myself up for the best chance of being productive each day.
Here are some of my current productivity correlations:
This is a fairly obvious one. The more I’m exercising, the more time I’m spending away from my desk. If I had a treadmill desk I might be able to turn this correlation around…
I’m pleased to see that I have a better day when I’m productive. I’d be in a tricky position if being productive put me in a bad mood!
Although I don’t work at night, a warm overnight temperature usually means less sleep (or lower quality sleep), which doesn’t bode well for a productive day. It also means it’s likely that the next day will be warm, which makes me uncomfortable and less likely to get work done.
I can also see from my correlations what affects my mood, and when I’m more likely to exercise:
Lots of floors climbed could either be walking up and down hills (yuck) or staying home all day where I go up and down stairs a lot.
I don’t purposely go out walking in the rain, but I guess it just happens to catch me often.
Exist has built-in mood tracking that works via a simple email. Every night at 9pm you get an email you can reply to including a rating for your day from 1-5 (1 being terrible, 5 being perfect) and a note about what happened.
Mood tracking is a really simple way to make sure you reflect on what happens each day and how you feel. We’re adding mood tracking to our mobile apps (currently in beta testing) to make it even easier: each night at 9pm you’ll get a notification that will take you to a simple form with five numbered buttons and a box to type your note into.
Although I tend to dread the effort of thinking back over my day and choosing a rating for it, I’ve found mood tracking to be so useful that I’ve kept it up for over a year now. As I go about my day, I tend to be more mindful of how things affect me because I always have in mind that I’ll be rating my day later and making a note about what happened.
My favourite part of mood tracking is that in the nightly emails we’ve added a feature called “Looking back” that shows you the mood entry you made on this day one year ago, or a random old entry if you don’t have one from exactly a year ago. It’s fun to open the email wondering how I felt and what I was doing this time last year, and to reflect on the notes I left to myself.
This reflective feature also makes me more mindful each night of what I enter as my note. Knowing that I’m essentially leaving a note to my future self each day helps me think about what was most important about my day, and what I’d want to know about it on this day in the future.
I also love comparing my old mood notes with my partner Josh to see what he wrote on the same day. We’ll often find we both mentioned something fun we did together, or the weather or some big news that was happening at the time.
Using averages as goals
We dropped goals from Exist a few months ago. One of the problems we’ve always had personally when tracking our behaviour, especially exercise, is working to hit a particular goal every day and losing motivation to do so after a while.
These days we use averages as goals. It works like this: if today is Monday, we create your steps goal for today by finding the average of your steps for every Monday in the past 90 days. We do this for productivity goals, too. So if you’ve been working late on Friday nights in the past few weeks, your RescueTime data will reflect that and your productivity goal will be higher on Fridays.
And here’s why it’s awesome:
I don’t need to waste any time setting goals. Exist does it for me, and each goal is personalised to me.
This also means I’m competing against myself. Every goal is created from averages of my own data, so I’m only ever competing against “past me”, rather than aiming for a goal set by someone else.
And lastly, it’s always up-to-date. When I moved house recently my average steps per day dropped as my situation changed, and after a few weeks my averages started to reflect that. Because we only use averages based on the last 90 days of your data, your goals will always reflect what your activity has been like recently.
This affects each daily goal, as well. If you play in a sports team on Wednesday nights and get lots of steps those days, your Wednesday average will be higher than other days. Exist will create a goal for you, then, that will be higher on Wednesdays than it will on other days. This makes sure your goal is always as appropriate as it’s based on your existing behaviour.
I tend to get number fatigue really easily, so aiming for a set goal every day didn’t motivate me for long at all. One thing I really enjoy about having a new goal created for me each day is that I need to check Exist to see what my goal is. The simple act of checking my goal is a good reminder to be more active or productive.
With just RescueTime, mood tracking, and an activity tracking device or app, you can get a lot of useful data. Exist connects to other service like Twitter and last.fm as well, but just a few data points are enough to start seeing insights and correlations that will help you improve your work/life balance.
You can try it yourself with a 14-day free trial (note: we start you off with a set goal and switch to averages as goals once we’ve collected enough data).