The Quantified Self

The Quantified Self

 How much have you moved today?

How did you sleep?

How fit are you?

How fresh do you feel?

Are you getting ill?

Should you train today or perhaps take a rest?


In recent years it’s become possible to take some of the guesswork out of these questions. We have never before had greater insight into the internal workings of our bodies. Wearable tech advances and the push to develop and market new devices means that these once niche products have bridged the gap from the sporting arena to everyday life. But there are pros and cons!


  • Observable data that’s always close at hand raises awareness. Awareness is the first step to monitoring and then to effective lifestyle or training changes. At a basic level, simply asking someone to write down their weekly food and drink intake will likely lead to them making changes to their diet. Become aware of how many steps per day you take and you’ll likely want to take some more. See your resting HR 5bpm higher after drinking alcohol and you may well want to cut back a little.


  • Measurable data (if accurate and reliable) can be used to back-up subjective feelings, but in my opinion shouldn’t be used the other way round. So, you feel fatigued and don’t feel like you had a restful night’s sleep and so you check your sleep tracker. Perhaps the fatigue is from overtraining or an impeding illness so you compare your HRV (heart rate variability). If the data confirms your suspicions then you can act accordingly. If it points in a positive direction then it may give you confidence to continue with planned training etc..


  • Many aspects of health and fitness can be measured or predicted by these devices and that can massively increase motivation to form new habits and routines or to remain engaged in sport. There’s nothing more motivating than seeing your numbers move in the desired direction.


  • Generally speaking, metrics measured directly (such as HR, steps, distance, pace, power, HRV) are more accurate than data than is produced from those metrics via algorithms (performance stats like VO2max, training status and effect; and health stats like sleep score, stress and body battery).


  • Objective data is often viewed as gold standard and therefore trusted above our subjective internal feelings and emotions but as mentioned above this should be guarded against. Trusting yourself improves with experience and mindful practice. Learning what an easy pace feels like to both your legs and your lungs is important, just as recognising what it feels like to tip over your lactate (anaerobic) threshold.


  • The ability to quantify ourselves and everything that we do can lead to overly-critical self-judgement. This is not healthy but is very common in my experience. While we need to measure things in order to ascertain whether our training or nutritional changes have been effective, we also need to keep a love for what we do. This is why I advise going naked each week. Leave the tech at home or at the very least don’t look at it. Ride with friends, run a new trail, swim with sole focus on technique, try a new gym class or get the paddle board out occasionally. Feel good, be in the moment – don’t judge!


Coach Phil


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