It’s no secret that I love data. Numbers, analytics, stats, you name it. And when it comes to assessing my performance, I will admit that I almost always look to the numbers to tell me how I did. It’s something my cycling mates have given me grief about for years, but it’s a part of who I am so I’ve just accepted it. I’ve tried fighting against it, and often I’ll ride with just the map screen on my Garmin so that I cant’ see the numbers while I’m riding. But afterwards, when the ride is over… I’ll always look at the numbers.
And more recently the numbers have suggested I am not fit.
After the month and a half of ultras (see the write-up here and here if you’re interested), and then a complete 4-week break off the bike, my return to riding was brutal. Yes, I knew I would lose some top-end fitness and that I’d put on a bit of weight but I figured the endurance base wouldn’t disappear. This turned out to be true, but as it also turned out I had had a lot more fitness than I had given myself credit for. Which meant my first ride back after the break (a 200km road ride) nearly did me in. I suffered. SUFFERED through the day, and by the end of it my Garmin let me know I’d need to lie down for 72 hours.
The next weekend I went out to Little River (down by the You Yangs) and road a 180km mixed terrain ride. And I died again. Ended up walking up the last hill as my head, heart, and legs just exploded. My heart and chest ached, and it felt like I just couldn’t breathe.
The aching in my chest was causing me some concern (along with the heart ache of feeling generally like I wasn’t myself anymore) as it felt super uncomfortable. I’d feel sore for a day or two afterwards, and then everything would be okay. Except it was flaring my anxiety, which makes it always hard to tell if I’m having a heart attack or a panic attack. Same same. But I wasn’t sure if all this high heart rate training was healthy for me. I knew I had a pretty strong heart (I’ve had ECG (electrocardiogram) tests before and they always roll their eyes and say ‘athlete’ which I’m guessing means it’s all okay) but was it really good to pump it quite so much? Googling ‘heart problems in endurance athletes’ doesn’t provide much reassurance either.
When I got sent this study from La Trobe University I looked once, twice, and then called Daniel to chat.
The chance to get data, actual solid factual data, on my fitness, my heart, and my body composition seemed like a fantastic opportunity. Academic research to support or discount my own biases in terms of my training? Yes please! Daniel had a few chats back and forth, and he sent me all the details and calendar appointments for the 10 day study A little while later and it was time to drive up to Bendigo for my first set of tests: VO2 max.
FTP, VO2 Max, LTHR, RHR, MHR, HRR, and other acronymns
If you already know what all the details are around these please feel free to skip to the next section. But for those who need explaining on all the jargon (or are curious) here are some basic details.
Cyclists tend to most commonly measure their functional threshold power (FTP) using some sort of torturous test (ramp, 8 minute, 20 minute) to estimate what power they could hold for an hour if they went flat out. This power number is then used to train around for those that use a power meter. It’s calculated irrespective of your heart rate, so is considered more objective as your heart rate can be affected on a daily basis by hydration, temperature, adrenaline and blood sugar level. And anxiety. Yay.
“Coaches will often use FTP when programming workouts in order to get more specific about interval sets… FTP doesn’t just give you a threshold number; it helps create “power zones,” which can be used to hone your training.”
See more here
VO₂ max is the maximum (max) rate (V) of oxygen (O₂) your body is able to use during exercise It can give you insights about your cardiorespiratory fitness, such as how long you can sustain a certain intensity of exercise. The bigger it is, the more time you are can hold moderate or high intensity exercise. So essentially, the more oxygen your body can use, the more your muscles can work.
“Although VO2 max is a good marker of fitness, it does present some downfalls. You can’t really get an accurate measure of it except in a lab with expensive clinical equipment which is why VO2 max is usually a fitness marker reserved for elite and professional athletes.”
See more here
Lactate threshold heart rate (LTHR) is usually measured by taking the average heart rate that you’d hold during your all-out 1 hour FTP test, or your average heart rate for a 20 minute max effort. Lactate threshold, for an untrained person, usually coincides with 50-60 per cent of VO2max, ranging up to 85-95 per cent of VO2 max for an elite athlete. Or, you can get it actually tested:
“Lactate testing is the gold standard for determining exactly what is going on in the body… Compared to testing for heart rate and power thresholds, accurate testing for blood lactate is a lot harder to find unless you have a batch of scientists to hand. The test consists of taking blood from a finger stick during a VO2 max test so it can be analysed for its blood lactate concentration.”
See more here
The other three acronyms are measures of your heart.
- RHR (Resting Heart Rate) is the number of times your heart beats per minute when you are chilling out (and ideally not having a high anxiety day). Usually, a lower resting heart rate means your heart is working more efficiently and is more fit. For adults, a normal resting heart rate ranges between 60 and 100 beats a minute.
- MHR (Maximum Heart Rate) is a tricky one, as there are a few ways of working it out: calculations, lab tests, and field tests.
- The typical measure is taking 220 minus your age.
- However, a more precise formula is 207 – 0.7 x age.
- Or, for active people, 211 – 0.64 x age.
- Keeping in mind these values are for men, and generally women have 5-10 bpm higher max HR than men. The more you know.
- For me, I just use the max heart rate I’ve gone during ‘field tests’ (aka: riding my bike in the wild) as it’s easier to push myself out there than in a lab test/simulated situation. Which for me is roughly the same as the active people calculation plus adjustment for women, so: 211 – 0.64 x age + 7.5.
- HRR (Heart Rate Reserve) is easy once you have the above two numbers, as it’s the difference between MHR and RHR.
Whatever numbers you have can then be plugged into any training program in a variety of ways to get whatever outputs you’re aiming for. I had a few of them already, but not the tests reserved for elite athletes with access to a lab.
Luckily, thanks to this research study, I had a batch of scientists to hand. So on to the testing.
Welcome to confrontationville.
Needless to say any mention of doing a ‘test’ kicks in the anxiety, so the few days before I could feel my body ramping up. It probably wasn’t helped by the fact I’d gone and done a hard (but immensely fun) ride with the boys the weekend before so it was taking my heart a bit of time to calm down and come back to normal. The morning of the test I woke up with a normal resting heart rate and a near full body battery, so I knew I was ‘good to go’ physically, even if mentally I wasn’t there.
For anyone who’s tried to get their blood pressure taken and resting heart rate measured while having an anxiety flare, you’ll feel my pain. For those that haven’t, it’s like doing a sprint and then having someone ask you to calm down. Eventually I managed to focus long enough that I would will my heart to slow down, and we got a heart rate and blood pressure reading that wasn’t ridiculous.
Next up was the VO2 max test and the lactate test which I was very nervous about. What if my numbers just sucked? I’d made jokes to Daniel to expect the numbers to be largely underwhelming, but this was mostly me trying to set myself up for disappointment. I tried to console myself by saying facts, not feelings. I had just come off a month of rest. I was not in any shape other than endurance. I hadn’t done anything resembling training since last year’s 4-month lockdown. The only sprints I did were to the front of the line at the bakery to buy donuts. I was a downhill specialist.
It didn’t help that I couldn’t get the first face mask on and was literally gagging trying to breathe. Putting a tube in my mouth and a nose plug over my nostrils to cut off the air resulted in a near panic attack, and I’m sure there were little tears running down my face as I tried to be brave. But I just couldn’t do it. Luckily they had a back up option of a face mask set up, and with a bit of finagling we got it sorted.
For those wondering what the setup is:
Simultaneously I was also doing a lactate test, which involved being pricked in the finger to draw blood to measure the lactate accumulation in my blood as I ramped up the test. Living my best life right here folks.
Trying to then calm down again we started the test. Only to realise 10 minutes in that the power wasn’t increasing and the test wasn’t working. I sat calmly (haha) on the bike, still fully face-masked up, while they apologised and tried to get the set up working again.
For anyone that’s ever done an FTP test at home or wherever, it’s the same thing, except you’re concurrently trying to breath into a plastic face mask and not vomit or pass out while having someone stab you in the finger trying to draw blood. At the same time they were calling out all the numbers (8 minutes in! Power 180, VO2 at 28.7, heart rate 141) which of course made me even MORE aware of what I was doing. Daniel was casually chatting with Matt (who was taking my bloods and is a triathlete) about numbers, and Matt mentioned his VO2 max was 49 point something.
Me: Must… get…. to 49…. (stupid competitive genes).
I had no idea what 49 meant by the way. But it seemed a long ways away, given I was only at 28.7 at that time.
Needless to say I eventually completed the test. It’s a fun one, everything seems pretty okay until it is SO NOT OKAY and then it’s a battle between everything screaming at you to stop before you puke and yet desperately trying to keep going because 49.
And then it’s over.
And I couldn’t breathe. The guys were all writing numbers down and finishing up the test, and I was trying to figure out how I could rip the mask off without breaking all the equipment. My desperate wheezing must have alerted them to the fact I was not okay, and they quickly got the mask off so I could gulp in as much fresh air as possible. Sweet sweet relief. A 5-10 minute cool down at low watts and I was fine again.
The numbers: Heart Rate Zones
For those who like graphs rather than a spreadsheet of raw data (weirdos) here’s the run down of what it all means. The orange line is my heart rate, which climbed fairly steadily through the test. The blue dots are the measures of lactate in my blood stream. At some point (probably around 11-12 minutes in), my body isn’t able to clear lactate as quickly as it is produced (the blue dot starts climbing. Fast). And then my legs start burning, the chances of me vomiting increases, and it all goes pear shaped pretty quickly. Overall, it gives me a good idea that my anaerobic threshold (LTHR) is probably somewhere around 160bpm (155bpm through to 165bpm) ish.
Knowing these numbers I was able to plug them into a HR zones spreadsheet a friend had given me ages ago (see: when I first started riding my bike and was actually training). It’s a handy one, as it works out your training zones based on your heart rate reserve (HRR), max heart rate, as well as lactate threshold heart rate. Different coaches and different training plans use different zones, so now I had access to a range of zones.
What does it mean for me. It’s pretty simple (in a complicated way). When I usually went out riding (on solo rides) I would keep an eye out on my heart rate as an indication of how hard I was going (no I don’t train with a power meter on my bike when I’m ‘in the wild’). If I was going on an all day session (say a 200km ride) I knew I wanted to keep my heart rate in the ‘blue zone’ as much as possible. It would rise into the green/orange zones on climbs or if I started pushing it, but in order for me not to have to limp the last 50km home (or make the phone call of shame) I generally wanted to be in the blue (endurance) zone. For someone who naturally pushes herself and likes to work hard, I would quite regularly push past the blue zone and sit in the green for large portions of my rides if I wasn’t careful.
Prior to this test I had the top end of my endurance zone at 148bpm, so my tempo started at 149. However, I’d done a few long rides where I quite comfortably sat around 155, and couldn’t quite reconcile how I had done that if that was all in my tempo zone. Maybe I had a weird physiology where I could hold tempo for a lot longer than a ‘normal person’ could?
Or maybe, I didn’t have my numbers right, as the top end of my endurance zone is actually 155 (see the average of all on the far right of the chart).
Does it matter? Not really, except for the fact that I do look at the numbers quite a lot and having my heart rate over 148 tends to trigger some anxiety when I’m riding because I ‘knew’ this wasn’t a zone I wanted to be in. So it’s more about me telling me to chill out and that it’s okay. And because riding ultra distances can be so much more mental than physical, any mental tricks I can use to calm myself down are super useful.
The numbers: VO2 Max and FTP
Did I beat Matt the triathlete guy? Nope, sure didn’t. And trying to figure out if 49 is a ‘good VO2 Max’ is is surprisingly difficult, and varies widely depending on where you look (for a fun party trick google “cycling vo2max chart” and click on images.). And it differs quite a bit between men and women. For example:
Based on these three sources (see here, here, and here if you’re interested) Matt’s score of 49 would make him a ‘superior’ ‘high’ ‘excellent’ ‘highly active’ athlete in his age bracket. If I had this same score I would be off all of the charts for most of the measures.
I tried looking for better sources (see: academic journals) but even they struggled. “Existing normal standards are problematic because they tend to be population specific and thus lack portability, have generally been derived from single-center samples that lack normal distribution in terms of fitness and other demographic variables, and are poorly represented by women” (p 26, reference below). But they did develop this equation for predicting VO2 max:
Using that equation, my predicted number is 39.4. So I could assume that if my actual number is higher than my predicted then I’m doing okay.
Comparisons of Functional Threshold Power (FTP) are easier, have a look at this chart for those numbers.
From the test, it seems I’ve got a fairly high VO2 Max (at 48.2), but a moderate-good FTP (of 243). Overall, when it comes to my VO2 Max and FTP, I can produce a lot of noise (oxygen) but I don’t go anywhere fast. Seems about right.
Tell me your heart is happy
The next day I was back in Bendigo for some more surveys and some tests on my heart. This meant a rather early start to the day, which was ironic given the first questionnaire I filled in was a morningness-eveningness test (click here if you’re interested in your own circadian rhythm). I’ve always considered myself an evening person (as does anyone who’s had to deal with me in the morning) but it turns out that I’m an ‘intermediate’ who leans more towards being an evening person. It also suggests my bedtime is naturally around 12:15am, which explains why it’s such a fight for me to try and get to bed earlier than this, and why that 5:30am alarm really sucks.
After a bit more paperwork it was time to get on the hospital gown and get my heart scans done. Lots of acronyms that I didn’t understand were rattled off, and cold lube applied to all sorts of instruments, along with more buttons and stickers on my chest. Looking it up later, I had the structure of my heart assessed via a two-dimensional ultrasound (see the picture below) as well as an ECG to evaluate my heart’s electrical function.
I have no idea how to read these charts, but Rachel (the woman doing all the tests) didn’t seem overly worried. In fact, during the ECG she rolled her eyes and mentioned ‘athletes’ under her breath, which I’ve heard before, so I’m assuming everything is good.
Still, for the next 5 days I’ll be ‘wired for sound’ wearing a fitness tracker and heart monitor.
This is to set up the ‘control’ phase of this experiment. This means no exercise. No intervals. No cycling. No training. Just, you know, walking around and chilling out and stuff. The idea being to establish a baseline for my heart’s functions when I’m not exercising, so that later we can compare the results to when I am exercising, as well as how I cope after the exercise.
At the time of writing this I was 2 days into the 5 days of the control period. Which meant two nights of having extra anxiety around sleeping (did I mention that tests increase my anxiety? So being essentially monitored ALL THE TIME is extra fun times right now). I’m also filling in a food diary, which is fun because now I’m hungry all the time but feel a bit guilty about sneaking in snacks, so have changed how much food I’m putting in me. Which is probably a good thing, given I’m not exercising so don’t actually need all the extra calories that I normally put in.
We’ve also just had the news that Victoria (the state of Australia where I live) is going into a 7-day ‘stage 4’ lockdown. So the kids are at home being homeschooled, we can’t leave the house except for 5 reasons, exercise is limited to 2 hours a day, and we have to stay within a 5km radius of home.
Seems like a good time to be chilling with all these wires on me.
However, it does mean that the next phase of the experiment (the 6 hours of cycling on an indoor bike while having a bunch of stuff monitored and tested) has to be pushed back as it falls within the lockdown period.
So stay tuned I guess, as we’re now playing the next phase a bit by ear, pending lockdown.
If you’re interested in hearing more about how the tests go, please let me know in the comments!