Wbal does anyone use that metric? Calling all my smart teammates
So I did an FTP test and noticed that the Wbal graph in Golden Cheetah was very straight and angled down, going negative near the end of the interval and I wondered what it represented.
I looked it up and it supposedly represents the energy reserves that can be used anaerobically. Those reserves deplete during a long anaerobic effort and replenish at efforts below the aerobic threshold. I have noted this value but never seen it have such a long decline (until I looked back at old FTP efforts). Does anyone else find this useful? Specifically, how negative can one actually go? This seemed like about all that I had in the tank during this effort. Also, it seems like that might be interesting info to have on your bike computer during a ride in order to estimage how much left in the tank for judging sprints, etc. Thoughts from the smart people in the crowd?
Comments
@Ralph Moore - I have heard of this from the WKO perspective. It's known as Dynamic Functional Resource Capacity (more here). I see it as the purple line here:
IIRC the DFRC is more used for Anaerobic stuff, as it really shows how hard you worked....and when you are back. As "hard" as threshold it, it's nothing compared to a hard all out interval session.
I am not sure if you can do the math live, but that would be pretty cool. Might help me save a few about to go really wrong Zwift races! 🤣
~ Coach P
Hey Ralph,
W' in particular is one thing that I really like about Golden Cheetah. I can't give you a detailed scientific explaination of W' (Wbal), but I equate it to your full tank or energy reserve which is constanctly being drained (variable rate) and refilled (at a constant rate) during a particular activity. The larger your W' the larger your fuel tank, the bigger your fuel tank, the longer your can sustain a particular effort. Now, the other aspect of this is that your fuel tank is always filling at a given rate. If you stop to recover, your tank will start filling up again. If you happen to reach zero, you should be absolutely toast at the end of your effort.
From your chart, that would be something that I would expect to seefor that type of effort. Below is chart from a previous FTP test I performed.
In GC, the important thing is to make sure you have it set correctly. You can set it GC in the same place you set CP and FTP by going to (Tool>Options>Athelete>Zones>Power Zones) If set correctly, you should see a chart like the following during interval workouts on your chart during hard efforts. The below chart is the result of a Z6 interval workout I did yesterday.
The part that I really like most about using W' is in the workout designer under the "Train" tab. It's a great way of gauging the intensities and time of each interval before your do the workout. It gives me an idea of where I almost approach complete failure but don't and can back off and recover to do another one. It helps me adjust them without completely blowing up in the process and doing an effort I should have never attempted.
Anyway, not a really great explaination but that's how I think about it and use it for my training and workouts from time to time.
As Coach P noted above, in WKO it's referred to as Functional Reserve Capacity. Hunter Allen put out two really short videos on it recently.
Part 1 https://www.youtube.com/watch?v=UX87gBDA-Dk&feature=youtu.be
Part 2 https://www.youtube.com/watch?v=Ftr8_uCxJKY
Tom
Thanks, that is very helpful. I am going to guess that, since I was able to go negative during my FTP test, that my wbal is set too low. Seems like the situation where you work harder than 105% of your "FTP" for 20 min because it was set too low to begin with.
I am intrigued and will look into it more.