Is anyone regularly using DFA Alpha 1 to ride under the aerobic threshold?
I got a Polar H10 and HRV Data Logger. It seems to work pretty well. My aerobic threshold seems to be bang on with what I determined years ago with Seiler’s 60-70% of HRmax estimate. For me that range is 113-132bpm.
On my first DFA Alpha test, I was staying above the .75 threshold right at 130bpm. If my HR blipped up a couple of beats I’d dip under the threshold.
On my second test, about 125bpm was right. 128bpm pushed me under .75.
I was also extra tired, and noticed that 45 minutes into the ride I had to lower the intensity quite a bit to around 123bpm to stay above .75.
So what is the conclusion with DFA Alpha 1?
Just keep riding at 125bpm or under for low intensity rides?
Do intervals at 125bpm to track power at that HR? A gauge of aerobic fitness?
I’ve learned that it is more sensitive than I need. Upper 120bpm and lower 130bpm are the same thing. Technically mine is about 128bpm, but I’ve measured it as high as 133bpm.
If I have a sustained effort that falls (for example) around 110-118bpm, I pick up my pace unless I’m tired, in which case just above 110bpm is fine. If I have a sustained effort that falls in the upper 130s, I lower intensity. I consider 126-134bpm to be exactly the same thing.
Power at that HR, as well as power just lower and just a bit higher will improve with aerobic fitness. By tracking it at 125bpm, you are tracking it at 120bpm (or 130bpm, etc). 125bpm is as good a level as any other in that neighborhood.
I use it a lot.I also use the FatMaaxer app ( Android Project to find FatMax in real time with a Polar H10 )on Android to monitor it when I’m on the turbo in realtime. I’ve found that the power & heart rate values can vary quite considerably depending on what state I’m in. If this 0.75 thing is an accurate representation of where VT1 falls then I reckon that is a good thing. Bruce Rogers has written about this in his blog. Muscle Oxygen Training: To train hard or not, that's the question. I found that according to this method, when I’m fresh, my heart rate is at VT1 is higher (79% of HRmax) than I would have expected, as is, to a lesser extent, the power.
@AJS914 Let me just say one more thing that may not be clear in my response. I don’t question the accuracy or the validity of the approach. Sure, Bruce Rogers needs some science-y folks to further validate what he’s published, but it’s good enough for “field testing”, IMO (and obviously more convenient than lactate). I saw good alignment with what I was seeing with other approaches suggested by my coach (lactate, breath, etc.). I simply don’t use it on a day-to-day basis.
Exactly where I’m on it. I tend to ride a bit lower than where I think VT1 is on the flat. Let it creep up a bit on hills. Back off if I sense my breathing changing. If anything be conservative in where you ride at, if monitoring via HR.
Also if doing a longer ride. VT1 is considered a physiological turn point. So to stay around that turn point power will need to drop as time goes on. Listen to your body and breathing as well as look at the numbers on a ride.
At least I have this in common with young Mr. McNulty. The only problem is that’s 20bpm below my LTHR…
LT1 HR should stay pretty consistent, as a percentage of LTHR. Mine’s always been 30bpm below the second threshold. The problem is that the HR for both turnpoints has gone down a bit over 35 years.
when I look back at old data from the 90s, my efficiency factor has not changed much at all – still around 2.25 w/HR. What’s changed is that my LTHR was 10 beats higher when I was 25 (30 years ago).
Usually August through October as my main events of the year are complete by then. With nothing major till following Spring.
I find my ability to keep the same pace over many hours at or close to VT1 improves over that period. So call it my all day pace / stamina improves.
It’s not big leaps or anything like that. But suddenly at the end of the three months you look back and realise the improvement there has been. I keep notes on my rides which helps a lot with assessing this. Rather than thinking I’ve improved.
The top end suffers a bit as I’m not doing so much intensity. But the top end soon comes back once I reintroduce more intensity in November and gradually ramp it up towards early Spring events.
Does anyone think a portable breath analyzer such as a Lumen device would serve as a somewhat consumer accessible way to estimate LT1 based on RQ (RER)? Their company product seams like an incredible untapped tool to allow for Aerobic Threshold estimation without having to use blood lactate. Without it being on the face all the time like a mask I can see it being prone to error, but, I can also see it being used for spot checks. If anything, I am wondering if it could at least allow one to know when I reach my aerobic crossover point relative to wattage. I want to train at my wattage Zone that optimizes fat at the fuel source. A spot check would allow me to know when I go over that point. Thoughts?
I actually checked that thread out last week, was going to give the HRV Logger app a try since I subscribe to HRV4Training Pro and they seam very much in the Zone 2 polarized camp over there. Seams like a interesting way to estimate LT1. Or at least attempt to. I actually came to this thought the other day because I realized FirstBeat algorithms on my Garmin estimate my LT2 using HRV (FTP as well). So I asked myself, why couldn’t HRV be used for LT1 approximation too? Behold! This thread with that same thought haha.
Unfortunately not. In order for the device to work correctly you need to be relaxed with your Heart Rate as near to its resting level as possible. It only give an estimation, on a scale of 1 to 5 of the ratio of carbs & fat you are burning at rest.
