A Guide To Self-Tracking. Using Data To Optimize Long-Term Health And Fitness

If you can’t measure it, you can’t manage it.

self tracking

We live in a data-obsessed world. Each day business decisions are made on the back of big data analytics.

The data doesn’t lie. It is more reliable than a hunch, a gut feeling or a guestimation. People claim data is the new oil and they are right.

The same applies to your health too. We are lucky to live in a world where we can gather reams of health data from our body. This includes data points of one like measuring your weight to data points of trillions by analysing your gut microbes.

When it comes to health and longevity there has never been a better time to be alive. Science understands more about the human body than ever before and continues to make new discoveries.

We are in the midst of a digital revolution with biology and technology merging and data underpins it.

Self-tracking is not new.

Watch interviews with Arnold discussing his bodybuilding days and how he meticulously recorded every rep, set and weight after each workout.

Benjamin Franklin was the first known self-tracker. He devised a list of 13 virtues that he would mark himself on at the end of each day.

This article outlines how I use technologies to self-track and optimise my health and fitness.

Why is self-tracking important?

The point of any kind of data collection and analysis is to spot trends and changes within the numbers.

It allows you to notice changes in your body you may have otherwise missed. Management consultant, Peter Drucker said, “If you can’t measure it, you can’t manage it” and the same applies to your health.

For example, imagine you’ve been hitting the gym and eating healthy for three years. During each year, you go for a DEXA scan to ensure you’re building muscle mass, losing body fat and improving your bone density.

The yearly data from the DEXA scan will ensure you’re on the right track with your training and diet. Assuming that the data shows year-on-year muscle and bone density growth and body fat decline. If the data shows a decline then you would put in the necessary changes (increase your workouts and improve your diet) to reverse it.

Self-tracking is about taking control of your own health. It provides necessary information to make adjustments. Whether that’s increasing your training, improving your nutritional intake or removing bad habits. 

Long-term self-tracking will provide you with trends to help you decide where you need to focus your effort.

If you’re middle-aged and your muscle mass is decreasing year-on-year you should do resistance training before sarcopenia kicks in. If the quality of sleep you’re getting is not as good as it was then you should test sleeping aids. If your testosterone is showing a downward trend then consider TRT.

What and when should I start self-tracking?

In short, the more useful data you can collect at the earliest possible time the better. I track a range of variables and have been doing so for some time. Technology helps and there are lots of self-tracking apps, devices and services available. Some paid for and some free.

If you don’t self-track then the best to start is now. It’ll allow you to set a benchmark and will provide a snapshot of your current health and fitness. If you’re anything like me you’ll use this data to get better each year. It doesn’t always happen since life sometimes gets in the way but being in competition with yourself helps.

Below is a list of variables I track about myself. I started five years ago and have evolved it from there.

Tracking body composition

If you’re a man, tracking body composition over time allows you to see if your body is feminising by losing muscle and gaining fat. It gives you an indication of how successful your lifting and diet is.

I’ve written a review of the DEXA scan before. It’s considered the gold standard of body composition measurement and it’s what I use to analyse mine.

The DEXA scan provides an accurate analysis of:

  • Muscle mass
  • Bone density
  • Body fat

Not only does it tell you how much fat you’re storing but also where you’re storing it too.

DEXA scan review
The DEXA scan print out

I also have a set of digital bathroom scales I use to weigh myself every fortnight. Body composition is far more important than weight but the scales are an indication and are easy to measure.

If you’re serious about changing your body composition, have a solid training plan in place and you can afford it then have a DEXA scan twice a year.

Tracking strength workouts

Each time I hit the gym to lift I track the reps, sets and weight lifted. Even on a casual day and I’m not looking to train hard I record everything as it’s ingrained as a habit.

Tracking each workout is easy. I open up a draft email on my iPhone and add the data to it as I go. When the workout’s finished I email to myself and then add it to a Google Doc spreadsheet when I get home. he same spreadsheet is used via the Google Sheets iPhone app while I’m training so I know what I lifted the previous week.

When I’m training to improve on the previous week’s lifts I have the same spreadsheet open via the Google Sheets app while I’m training so I know what to beat.

It’s basic but effective. My lifting is fairly steady at the moment but I plan on doing a six-month stint of hitting the weights hard. When I do I’ll crack out my previous records so I know what to beat.

If you enjoy competing with yourself as I do then this once definitely helps you increase your work ethic in the gym.

self tracking
Sample of the spreadsheet I use to track reps, sets and weight

Self-tracking the heart and cardiovascular exercises

VO2 Max

As we age, our aerobic fitness deteriorates. Strength is usually the last to go and some old dudes actually get stronger as they age. Aerobic fitness is one of the first things to go.

To keep on top of mine I have my VO2 Max analysed. This is to understand my body’s metabolic profile and personal heart rate zones.

VO2 Max test. Results: Athlete level #cardio #vo2max #fitness

A post shared by Ste Davies (@stedavies) on


Using this data I monitor my aerobic strength via HIIT (high-intensity interval training). For HIIT I personally use the treadmill, but a rowing machine or stationary bike work also.

For a HIIT session I run on the treadmill for 30 minutes. It’s set to an incline of 1% and I sprint at 19kmph for 1 minute and jogging at 10kmph for 2 minutes. I repeat this for the full 30 minutes and when I’m finished by body completely drained.

I use the Polar H7 Bluetooth Heart Rate Sensor & Fitness Tracker (Black, Medium/XX-Large)   along with the iOS Cardiio app to track my heart rate, heart rate zones and calories burned. A sample of the data is below and it’s useful to see which zones I’m hitting and when.

Resting heart rate

Every couple of weeks when I’m focussed on fitness I wake in the morning I measure my resting heart rate. To do this I use the Azumio heart rate app. It uses the phone’s flash and camera sensor to measure how many beats per minute your heart is pumping through your finger.

The lower your resting heart rate the better as it shows your heart isn’t working hard to circulate the blood around the body. I usually clock around 50 to 55 beats per minute and according to the standard heart rate zones, I’m usually at ‘elite athlete’ level. This will be harder to achieve the older I get, however.

Self-tracking daily activity

The body needs to be constantly active to remain healthy. I’ve written before about the power of walking and how it’s the best kind of steady-state cardio. It has no impact on the joints and has little muscle fatigue so you can do it over long periods of time.

Walking is my main kind of daily activity. I lift heavy things, run really fast occasionally and walk as much as possible. That’s my fitness regime right there.

I use the Moves smartphone app to track my walking activity. It counts steps, distance walked and calories burnt, works constantly in the background with no interruption.

Health authorities recommend walking at least 10,000 steps a day. I aim for 20,000 which is around 9.5 miles. Keep active. Use it or lose it.

self tracking
Move apps tracks your distance, steps and calories
moves app
Move apps tracks your distance, steps and calories

Tracking nutritional intake

MyFitness Pal is one of the most popular health and fitness apps available. If you want to improve your body composition by losing fat or gaining muscle or both then you need to track how much you’re eating. Likewise if you’re looking to pack as

MyFitness Pal helps you track your macronutrients, micronutrients and calorie intake. When I’m training hard and eating well I’ll use the app for the first month of my routine just so I know what and how much I’m consuming. After the month I don’t need it as I stick to the same foods.

self tracking
MyFitnesspal daily nutrition tracking

Understanding your genetics

Manipulating your genes through diet, exercise and lifestyle is possible. Tracking the change, so far, is not possible though. That will change in the future but for now, we have to make do with what we can.

I’ve written before about how to analyze your genes for longevity, health and fitness. The insights I’ve gleaned from this data has allowed me to change my lifestyle, diet and sleeping habits in the process.

Sign up to 23andMe and have your genetics analysed to understand your risk to certain diseases and if you’re a carrier of anything. Then use the API to plug into third-party services that allow you to understand other parts of your genetic makeup.

self tracking

Tracking sleep

Prioritising good sleep is the most underrated health move you can make.

For about a year I wore a sleep tracking band on my head almost every night. The band had sensors on it that monitored my brainwaves as I slept so when I woke it could tell me how much quality sleep I had.

It monitored deep sleep, REM sleep, light sleep and counted how many times I woke through the night. It was an excellent piece of kit that not only allowed me to understand my sleep patterns but also helped me A/B test to get a better night’s sleep. Despite looking like a dick, the data it produced was worth it. A few insights include:

  • I found that my REM sleep was poor which is apparently a sign of low Vitamin D. I got a blood test to check my Vitamin D levels and low and behold I was deficient. My genetic analysis also confirmed this deficiency. I have a specific gene associated with low absorption of Vitamin D. Once I started supplementing my levels increased and so too did my REM sleep. Correlation does not mean causation but the evidence is damning.
  • I found out that the best time window for me to sleep was from 10pm – 6am. This is the time when I get the best quality deep and REM sleep. This still holds true today as I perform better when I’m in this sleep pattern. When I’m in a routine of going to bed late my daily mood suffers as a consequence.

The headband manufacturer went out of business or I’d still be using it today. Still, while the device was working I was able to obtain many insights into my sleep which have helped me create new habits to this day.

There are apps like Sleep Cycle that claim to do something similar but the data is only an estimation. I’ve tried them all and they don’t compete with the sleep headband which was ladled with brainwave sensors.

self tracking
The now-defunct Zeo Sleep Manager

Tracking hormones and other variables

Blood tests that analyse all the hormones and nutrients in your blood used to be both difficult to get and expensive. The first blood panel I had done in 2012 would have cost me around £600 ($750) if I had paid full price. Luckily I have a friend who works in healthcare that helped me get it for much cheaper.

Today it’s easier and not as expensive to have a similar blood test. Private companies now provide at-home blood tests at a fraction of the price. Companies like Medichecks provide a menu of blood tests depending on what you’re looking to get tested. Thyroid, Vitamin D, female hormone, male hormone and so on.

Getting a blood test every three to six months will allow you to see if your lifestyle is impacting your internal health and if you need to change your diet or use supplementation.

Like a lot of people, I have been Vitamin D deficient in the past which I found out via a Vitamin D blood test. Today I supplement with 10,000ius every other day.

self tracking
Medichecks blood test data dashboard

Testosterone replacement therapy (TRT) in the UK is growing. If you feel symptoms of low testosterone and you can’t get a blood test from your doctor you can use an at-home test. These private companies usually know much more about what to look for with low T than a general doctor.

Private testing companies usually know much more about what to look for with low T than a general doctor.

I recently had all the necessary blood tests for TRT. Not because I’m going on TRT but to have a benchmark of data that I can use in the future.

I used the Medichecks TRT Plus (UK only) blood test. It analysed a range of variables relating to TRT including red blood cells, white blood cells, clotting status, kidney function, liver function, proteins, iron, cholesterol, thyroid, prostate and of course hormones.

The results mostly were classed as ‘normal’ including my total testosterone and free testosterone so in theory I’m good for now. Whether these normal levels could be optimised with supplementing is another question.

Where to start with self-tracking?

Audit your current health. 

You need to create a benchmark. This will be your point of reference from now on. The more data you have from the outset the better. Assuming money isn’t a problem (and this is not the case for everyone) measure the following.

  • Height
  • Weight
  • Body composition
    • Body fat
    • Muscle mass
    • Bone density
  • Resistance training
    • Reps, sets and weight lifted
  • Cardio
    • VO2 Max
    • Heart rate zones
    • Resting heart rate
    • HIIT
    • Activity – steps, miles
  • Nutritional intake
    • Macronutrients
    • Micronutrients
    • Salt / Sugar
  • Genetic profile 
    • Behavioural genes
    • Disease risk
    • Fitness genes
    • Nutrigenetics
  • Blood work
    • Full blood panel (if possible)
  • Sleep
    • Hours sleeping
    • Quality of sleep

Figure out what your priorities are

If you want to go from fat to fit you need to focus on nutrition and exercise. Maintaining good health is complex but if you haven’t got the basics right then you have to start there first.

If you’re fit and eat well then you can start tracking more complex data like blood work or genetics. It all depends on where you’re personally at when it comes to health.

Take action

To maintain health we have to constantly remind our bodies that we are alive. We have to send those signals to the brain, muscles and organs, reminding them that they have to work to stay healthy. We have to push ourselves in the gym and we have to manage our cravings and go for the healthy option.

Self-tracking is worthless if you’re not taking action and being proactive about your health. Like most things in life, you need to take action.

Leave a Reply

Your email address will not be published. Required fields are marked *