Alex was diagnosed with type 1 diabetes in August 2013. This means that his pancreas no longer produces its own insulin, so in order to use any sugar from the food he eats he needs to inject insulin before every meal. On being diagnosed he was told that exercise increases the risk of low blood sugar, very low blood sugar can be debilitating and in extreme circumstances can lead to death.

Alex says “Physical exercise is extremely important to me, so I immediately started tracking data to give myself the best chance of managing my blood sugar safely whilst doing exercise. I track four things: grams of carbohydrate eaten in each meal, snack or during exercise; insulin doses; exercise; and blood sugar. The motivation to be able to continue doing the things I love is powerful and drives me to spend the 20 minutes a day needed to track everything.

“Self-tracking has enabled me to understand my body well enough to manage my diabetes both in every day life and during exercise. Since being diagnosed I have run an ultra marathon, the London marathon (getting a Guinness World record for the fastest marathon run in an animal costume!) and done plenty of mountaineering. Without self-tracking, my blood sugar management would be much worse.”

A self confessed cycling addict, Lindsey tracks every ride with a Garmin bike computer and the Strava app. This allows her to monitor data in real time and retrospectively view it in more detail. Strava has gained a dedicated following within the cycling community with 2.6bn Km of riding logged.

“I use the Garmin bike computer for every ride, training, sportives and racing. When riding, I train on my heart rate, keeping in certain zones depending on the ride and maxing my heart rate when I’m going for it. Often, fatigue in my legs means I get nowhere near my max heart rate.”

The Strava app logs a huge amount of data including distance, elevation and heart rate. It not only gives individual statistics and personal bests, it allows you to compare yourself with other users stats (worldwide there are over 640,000 separate road ‘segments’ on record and Lindsey knows many of her local ones very well). This social and competitive element is a huge part of what attracted Lindsey to the app and motivates her to keep riding.

“It records my yearly & all time distances / hours on the bike / biggest climbs. It's fun & competitive. It makes me train hard, knowing when I get home I can see whether I have improved my times on segments of road / ridden faster than friends. And very occasionally I become Queen of the Mountain (QOM) - the fastest lady to ever ride a segment of road / a route.

“There is a suggestion that you are addicted to Strava if you download before your post ride shower. No comment.”

Emotion and mood can be difficult things to quantify. Adriana uses ‘Emotion Sense’, an app developed by researchers at Cambridge University to monitor her mood and overall happiness.

At different times of day the app asks Adriana to input her mood on a grid with 2 axes, one for negative/positive feelings and the other for activity. The app can go further by using the phones data to measure environmental and social influences such as how much you are using your phone and how active you are through location tracking.

Simply by being asked to rate her mood Adriana found that she was generally happier than she thought “I have always thought that my mood tends towards negative but after a few months of tracking, it seems that I am actually a lot happier and positive. Self-tracking also showed me that I have become noticeably more balanced since I started doing yoga.”

Many people use self-tracking as motivation and encouragement to achieve personal goals. Francis is typical of this mindset, by tracking his weight and exercise he has quantifiable figures to work towards and personal best scores to beat. This approach began with a simple fitness goal and has expanded to other areas of life where he hopes to create more positive habits through goal setting and self-tracking.

“It all started with tracking my weight, body fat and BMI on a digital body composition scale using a simple spreadsheet. The act of tracking made me watch what I ate. I started monitoring everything I consumed, using both a food tracker app and an alcohol tracker app. This discipline made me stick to a diet for the first time in my life and it wasn’t long before I reached a healthy BMI.

“After I started losing weight, exercise got so much easier. I set a target of running in to work (Aldgate) from home (Shepherd’s Bush). The distance was 13km - I had never run 5km before, and couldn’t run 1km. So I started slowly and tracked runs with an app and then a wearable fitness tracker. I used habit tracking apps, heart rate monitoring apps, a sleep monitoring device and even measured my happiness along the way to constantly encourage me and optimise everything I could in my life.

“When I achieved work-distance, it was so ahead of what I thought was possible, I couldn’t really believe it. It changed me completely, I was now investing in weird devices to transport my shirt in my running bag and having to eat more and more just to give me the energy to make it through the day after a big run. I ended up tracking everything from the life of my running shoes and even the usable life of accessories such as sports headphones. After that all I could do was set further and faster goals.”

From January 1st until December 31st 2013, Julian kept track of almost 50 aspects of his life. Setting out to see how much you actually do in one year, he aimed to quantify as many aspects of daily life as possible. Areas tracked include Sleep, Food and Drink, Personal Hygiene, Travel, Media Consumption and Communication.

“I counted the number of popcorns I ate during that year, how many people I talked to as well as the exact time I spent in the shower. Most of these categories aren't really useful and my motivation wasn't about improving my life - I was more interested in how much you actually do in one year.”

The data shown covers beverage consumption, movement, personal hygiene and TV consumption for the first 4 months of 2013, having recorded much of the data in notebooks Julian is still in the process of digitising and analysing his data. He found that tracking data did influence his behavior and is already drawing insight from the data gathered.

“I tried to think about the tracking as little as possible in order to stay as objective as possible and not change my behavior. However, I caught myself drinking more water to stay hydrated and going for more runs to stay active. I didn't just want to track how much I drank but also look at the different beverages and how those changed over time. For example, you can see that my coffee consumption decreased massively when I moved from Milan to Vienna at the beginning of February.

My initial goal was just to do a one year project but I got kind of addicted to it so I kept counting a couple of categories last year. I'm working on a new but slightly different project for 2015.”

Jonathan has had life-affecting issues with anxiety and insomnia for the past 4 years, treatment can be a complex issue with doctors reluctant to prescribe certain medications because of their proclivity for tolerance and physical or psychological dependency. Self-tracking allows Jonathan to manage his medication, monitor his sleep and provide evidence to his doctor of the effectiveness, or otherwise, of his treatment.

“The problem with all these drugs is there's a huge public stigma against them, especially for non-short term use. The GMC approve them for prescription for periods of 1-2 weeks under supervision of the doctor, and only with extenuating circumstances can they be prescribed for longer, and even then only by specialist doctors; my GP couldn't help, I had to go private.

“Shortly after seeing my psychiatrist we found what is for me, the perfect combination of medication: Zolpidem, to get me to fall asleep, Nitrazepam for dual purpose, help me stay asleep and also for what is basically a permanent dose (because of the half-life) of benzodiazepines, which lowers my body's natural inclination to anxiety. Finally there's Alprazolam (brand name Xanax – incredibly popular in the US; difficult to get prescribed in the UK) for acute management of anxiety. This was January 2010.

“My QS tracking along with a trusting and open relationship with my psychiatrist allows him to prescribe, for the duration I need them, the drugs I need to live a normal life. My QS tracking gives him the evidence he needs to demonstrate to the General Medical Council - and they do check up on these things - he's being responsible with his prescribing - long term, probably for the rest of my life – these 'addictive' drugs. This, in turn, means I get to continue to live a life where my anxiety and insomnia are managed; and I get to enjoy my family rather than being a wreck at the end of the sofa, not wanting to leave the house.”

Cathal is interested in tracking every area of his life through lifelogging, he has a large archive of about 4TB of lifelog data. He says that “In my lifelogging, I capture as much as I can, because every piece of data has the potential to be important at some point in the future. I began in 2006 and have every day since then visually captured using wearable cameras (about 15 million photos), location logging, biometric sensing and more recently, information access sensors”.

Cathal likes to build software and to make search engines that can extract meaning from sensors. According to Cathal, “I started because I have a passion for search engines. It was the ultimate search engine challenge, to build a ‘search engine for the self’ that understands your life experience as digital memories and makes it easy to find any memory”.

Cathal’s lifelogging has a unique perspective; it looks out at the environment and people surrounding him, which is different to many other lifelogging forms, which examine only the individual. Cathal says, “Of course, extreme lifelogging using wearable cameras is not for everyone (yet) and it poses major issues in terms of data security and privacy. This is the next phase of my research, to develop privacy models for lifelogging.

He loves to explore sensor data and has a strong belief that to have true impact, the technology needs to be automatic and extract meaning from wearable sensors, as if by magic. This is what he is working on. In his view lifelogging opens up huge potential for individuals to improve their memories, personal performance, health, learning and social interactions.

“When I was 16 I wanted to lose weight - I knew that fad diets didn’t work; counting calories was the only approach I could rationally take. I made a list of the calories in food items by walking round shops looking at packaging labels (this was obviously before the internet), and started tracking my calorie intake, trying to keep below 1800 per day.

The weight dropped off; and by working out how much I’d lost, given that 3,500 calories equals one pound of weight, I could calculate the number of calories I needed to just maintain a stable weight (it’s about 2300 - more than the average woman: I guess because I’m tall and walk a lot).

Since then, I try not to exceed that figure. If I come in under, I end the day feeling happy; but that’s less often than I’d like - the thing is, I love my food! People assume that counting calories spoils the pleasure you get from eating, but that’s not true in my case. I don’t really limit my calories: I just count them. It’s a habit now. I don’t think I could ever stop.

I’m not sure how to explain the satisfaction I get from a nice graph or spreadsheet. Perhaps it makes me feel like I’m in control. Knowledge is power. Although calorie-counting doesn’t necessarily help me lose weight, I like the fact that I would never come out with something like “I don’t understand why I’m not losing weight”. I guess I’m the kind of person who always wants to understand why.”

Barbara and her family use a self designed app to track and influence their happiness. By creating and sharing tasks based on the 'eight areas of life' (Health and fitness, Home, Partner/Self Leadership, Friends and family, Finance, Career/study, Funtime and Me), members of the family can see what each other needs to feel happy and therefore support each other in achieving their goals.

For April 2014 Barbara set 80 tasks, achieving 76 which completed 9 of the 10 self defined stepping stones for her big picture of happiness and harmony. Tasks included recording in a gratitude journal each morning, choosing healthy food options and scheduling 15 minutes a day to actively listen to each family member. Happiness and wellbeing can be very subjective things to track, by quantifying such tasks she hopes that “We can draw on either our actions or awareness to influence our outcomes and achieve the balance of happiness within harmony.

“We find that we more easily notice the good, are curious and enjoy being responsible for finding solutions and not dwelling on problems. We enjoy the sense that by giving to ourselves we have more to give in life in general!”

Suran steps into a 3D body scanner once a month to map his body shape and record measurements that would be unreliable at best if done by hand. The scanner gives Suran precise measurements along with a 3D map of his body that can be manipulated to show how he will look if he gains or looses weight.

“I got interested in monitoring my body-shape after my Uncle died of a heart attack. One of the best predictors of heart disease is the size of your belly, but getting consistent and accurate measurements by a tape measure is hard. Even if you take several experienced tailors, they will all give you different measurements for, say, your abdomen circumference. The body-scanner, which I use once a month, gives me accurate and consistent measurements so I know that I am on track with my diet and swimming.”

Ash records every single weight he lifts during gym sessions, for example - his records show that he has shoulder pressed 82,884 kg over 3 years.

By self-tracking, Ash is able to work towards set goals for specific muscle groups and it allows him to accurately monitor his progress to track improvements.

“Mainly the goals were to increase muscle size and strength, as well as reducing body fat. I have tracked the weights I use for every exercise I do, so that I can go back and compare to see if there is an improvement in strength for specific muscle groups. This helps me adjust my workouts in order to ensure that I have well balanced muscle groups, which helps to avoid injuries and nagging pain. Keeping track of what weights I use helps me with future workouts as I know what weights to use. This ensures that my training is consistent and removes the guess work that a dodgy memory brings!”

Michael designed and built an app called Happiness as a technological alternative to chemical anti-depressants. At random times of the day the app asks him to rate his mood on a positive/negative sliding scale and he records whatever is affecting this.

“By staying generally conscious of my mental state I'm able to spot patterns and make changes before anything gets too overwhelming. Tracking my happiness has also helped validate various life decisions that I might otherwise doubt. I've been tracking my happiness for years but my tracking has been much more consistent since I started using this particular app.

“The last couple of year have seen a steady incline in my overall happiness. Depression or moments of intense unhappiness are largely a thing of the past and now I'm in more of an 'optimisation' phase than struggling with anything particularly difficult. It's been a while since the app has shown me a big red warning necessitating a painful life decision. I won't stop, just because I'm in a good place - I think staying mindful of your mood is more useful as prevention than cure.”

Owen, a qualified pharmacist, tracks aspects of his mental performance and the effect of coffee on his short term memory, reaction time and processing capabilities.

“My job is quite intense and I need to be on the ball all the time. When mental performance is at its peak, tasks are easier and quicker to do. It's about working smart, not hard. So, by tracking my cognition I can assess what is helping to give me a great day, or likely to make it more difficult!

“Every morning I have filter coffee blended with butter and coconut oil, while this does sound rather strange, it has a dramatic effect on improving my cognition. Coffee has great effects on the brain, but often doesn't last that long, however when blended with the butter slows the absorption giving a longer effect without that post-caffeine crash!

“When I first started, using a program called Quantified Mind, I checked my mental performance when I had coffee against when I didn't have it. The results showed significant improvements in the way my mind functions, and so I've been having it ever since.”

Over the last 18 months Danny has used a number of wearable devices to quantify the number of steps he takes each day, this data is shown along with his BMI.

“My interest in the quantified self is both personal and professional. I’m a PhD student at the UCL Interaction Centre, where I am developing an in-depth understanding of how people engage with activity tracking systems over a long-term. I have a particular interest in targeting physical inactivity, which is responsible for approximately 2.3 million deaths each year (WHO, 2009). We don’t yet really understand how well systems such as the Fitbit work to encourage people to be more active and I hope to solve this. Tracking my own steps has made me more aware of my activity and health: as a result I’ve lost a considerable amount of weight and am much fitter.”

Rosa began tracking her personal finances in 2009 because she was worried about how much she was spending, wanted to know where all her money was going, and even thought that someone had been stealing from her account.

Using a simple spreadsheet template and a banking app she records all of her outgoings. Using a card for virtually all purchases, Rosa is able to track and categorise everything that she spends money on.

“Not only do I know where my money is spent but also, and more importantly, I can plan ahead for where my money will be spent. Upon distributing my money across the categories I have defined I can get a clearer picture and focus my efforts to achieve everything I want to have.

“After tracking the data for a few months I recall drastically cutting out the concept ‘going out’. I didn't have the feeling I was going out that much but the figures said the opposite! I started being conscious of my lifestyle and now I enjoy a lot more when I go out. More sometimes does not mean better.”

Tracking has enabled Rosa to control her outgoings, save for the future and showed that it was in fact herself who was ‘stealing’ from her account.

*Figures altered for privacy

Ian began tracking his health in 1974, initially by recording exercise and weight along with occasional health checks. This all changed in 2007 when he was diagnosed with terminal cancer and given only weeks to live. His tracking went into overdrive, expanding both what was tracked and its frequency. Ian now records over 200 areas of his daily life including body composition using the Tanita monitor seen here, for such things as weight, muscle, fat, water and left/right amounts for each. From this information he deduces what is helping or harming his healthiness. To enable comparison, Ian records a long list of variables that includes exercise, alternative therapies, supplements taken, liquid intake, food, prescription drugs and biochemical measures (cancer markers, blood pressure, urine and blood metrics). His routine of tracking and analysing data means his spreadsheet now measures over 400 columns and 2,400 daily records. “I do many different statistical techniques to extract meaning, alas falling short of what I hoped for, due to my own mathematical limitations. Attempts to get help have so far failed, so I struggle on as best I can.” This focus and ‘struggle’ seems to be as influential a factor to his longevity as any of his tracked variables.

Ian began tracking his health in 1974, initially by recording exercise and weight along with occasional health checks. This all changed in 2007 when he was diagnosed with terminal cancer and given only weeks to live. His tracking went into overdrive, expanding both what was tracked and its frequency.

Ian now records over 200 areas of his daily life including body composition using the Tanita monitor seen here, for such things as weight, muscle, fat, water and left/right amounts for each. From this information he deduces what is helping or harming his healthiness. To enable comparison, Ian records a long list of variables that includes exercise, alternative therapies, supplements taken, liquid intake, food, prescription drugs and biochemical measures (cancer markers, blood pressure, urine and blood metrics).

His routine of tracking and analysing data means his spreadsheet now measures over 400 columns and 2,400 daily records. “I do many different statistical techniques to extract meaning, alas falling short of what I hoped for, due to my own mathematical limitations. Attempts to get help have so far failed, so I struggle on as best I can.” This focus and ‘struggle’ seems to be as influential a factor to his longevity as any of his tracked variables.