4. Happy Valentines Day!
Hello dear readers!
It’s Valentines Day - and I remembered the one and only Valentine’s Day gift that I ever received (I’m not a romantic) ! It was 2016, I was a fresh faced 30 year old, we spent most of our weekends in the heteronormative bubble of cohabitative renovation projects and I wanted to ‘get fit’ after a few years where I’d spent a lot of free time on the Avanti West Coast trainline commuting for my PhD. I’d started January trying to go for ‘one run a week’ and was working up the courage to join a bootcamp that happened on the local common (but in my head I needed to ‘get fit’ first). And on Valentines Day I was surprised with an actual gift (pretty sure I didn’t return the favour) from my supportive partner who wanted to support me in my fitness goals - a Fitbit Flex! This was pre-smart watch and heart rate tracking and the Flex was the generation of Fitbit that meant you could “say hello to all day tracking” - you could measure your steps, distance, calories, runs and sleep.
I made three discoveries from using this device for a few months. First, my first mile in any run is REALLY slow - even if I run with someone who shouts at me to go faster. Second, if you walk to any train station you’ll nail your step count. Third, I sleep badly. I sleep so badly that the Fitbit started giving me actual chronic anxiety about my sleep, despite the sleep tracking at that stage being first generation and probably not in any way accurate, and when I managed to lose my Fitbit somewhere between the Carousel Bar and the Marriot Hotel in New Orleans at an academic conference later that year I felt a little bit relieved (after 24 hours of combing the streets and my hotel room because I HATE losing things). I avoided wearables for the next 7 years, feeling I’d learned enough from using one for a short time.
In summer 2023 when Thea was coaching me some of the data she needed for her Level 3 qualification was about resting heart rate. By that stage I was so immersed in the amateur sports world I was even more suspicious about the benefits of fitness data versus the mental health outcomes of relying on an algorithm to tell you about your body. Anyway, keen to give my coach some helpful data I picked up another Fitbit. The SmartWatch technology has moved on a bit, but I still sleep badly. Luckily I have also read a book called The Power of When, self diagnosed myself as a chronically bad sleeping Dolphin, and am no longer trapped in an anxiety spiral by the power of this data. The resting heart rate data is vaguely interesting in terms of how it’s affected by sleep, exercise and menstrual cycle - but I also take it with a pinch of salt as my Wahoo heart rate monitor picks up different (usually higher) readings when I’m cycling compared to the Fitbit. Which is the real heart rate and does it even matter?
What is interesting from a sprinting perspective is how badly the algorithms rely on volume to measure fitness and health and predict recovery needs. Sprinting, and to some extent, track racing generally, is about short efforts at high intensity. TrainingPeaks takes your heart rate data and calculates something called TSS - Training Stress Score. Do a 3-4 hour bike ride and your TSS will be high and maybe dictate that the next day you should take it easy to recover. Do a 2 hour Sprinting session at Lee Valley - your TSS will barely register that you’ve attempted to get your legs to move from 0-100% effort in 10 seconds 20 times in that period and will tell you that you can go again tomorrow. Believe me, your legs will absolutely say the opposite!
I happily removed my Fitbit completely after World Masters in October 2023 and went dataless for another good while. I’ve picked it up again this year because having a watch is quite a useful way to be less reliant on my phone being beside me at all times. In the intervening year, Fitbit have introduced new functions - ‘daily readiness’ and ‘cardio load’. These seem to roughly equate to what Whoop offers - a way to measure your need for rest and your best days to go hard. This sounds great in theory.
The reality of these innovations is proving rather intriguing. For quite a lot of January, my Fitbit data page started with a dire warning that I was in danger of undertraining. Possibly I gave it unrealistic expectations by beginning January with some endurance road riding in Mallorca. However, as with track sprinting, it also can’t recognise the strength effort that goes into things like gym work. I walk out the gym with wobbly legs after 30 minutes pushing increasingly bigger weight on the leg press and squat racks and get told I wasn’t doing enough! It loved the fact I rode into London for some Regent’s Park laps on Saturday without any regard for the fact I was borderline hypothermic when I got home and went incredibly slowly for the final 10km because everything hurt. However, since the weekend Fitbit has gone the other way in its warnings. Every day it’s told me I have a high ‘readiness score’ - well slept, low resting heart rate and good variability, into my follicular phase of my menstrual cycle. Concurrently, I feel good. Yet, every day this week it’s said “Take it easy. You’ve really pushed yourself recently! To avoid overtraining, take some time to slow down and recover, Target 9-52 cardio today’. (That’s about 30 mins zone 2 effort like a walk to the station). This has continued despite taking Tuesday and Wednesday as full rest days to focus on work. If I were dependent on this data to plan my training I’d have done nothing all week at this rate!
The moral of all this waffle is that fitness data and algorithms have changed in 10 years - but still aren’t that useful to people trying to prioritise intensity over volume. I’ve heard that Xert’s Forecast AI might be trying to overcome some of these limitations - but it’s dependent on having power meter technology every time you ride. The most useful data measure in sprinting is probably still going to be how I feel in my own body - trusting the process of training, knowing that showing up and doing the training is more important than the data it spits out, knowing that muscles need 24-48 hours to recover from hard intensity efforts regardless of what the data says - as well as knowing that as an amateur with a full time desk based job my training plan is going to have to be dictated by availability, weather and when velodromes have training sessions I can attend. But maybe I’m missing something - probably something very expensive!
What do you think? Do you find your fitness data useful? How much do you rely on it? What’s the best Valentines Day gift you’ve ever received?