# Training with Power - CTL, ATL and TSB



## Ericv2010 (Nov 30, 2010)

To start off, I just want to note that I'm very new to training with a powermeter. I picked up a powertap PRO+ just before the holidays and for christmas, I received Allen and Coggan's "Training and Racing with a power meter" - I'm approximately 50% of the way through it at this point.

I've been logging power data since approximately the 1st of January and since that time, I've noticed my TSB drop from -15 to -54. Over the same period, my ATL has increased from 22 to 78. My CTL for the same period has increased from 6 to 24.

I understand that my ATL is influenced by my training/rest balance over the last 2 weeks while my CTL score is made up of my training/rest balance over the last 3 months with increased ATL scores essentially 'dragging up' my CTL score.

For those familiar with TrainingPeaks (online site, not WKO+ desktop version) and with the principles of training with power, my basic question is as follows: 

If my both my ATL and CTL have increased (and are positive) since January 1st, why is it that my TSB has decreased (and has never been positive)? Based on what I know/have read, it would seem as if the TSB would fall somewhere between the CTL and the ATL scores.

can someone help please?
eric


----------



## asgelle (Apr 21, 2003)

TSB=CTL-ATL. 6-22=-16. 24-78=-54 

Unless you put in accurate starting values for CTL and ATL starting Jan 1, none of these values should be considered reliable for at least a couple of months.


----------



## kbiker3111 (Nov 7, 2006)

Yeah, since your ATL accumulates faster than your CTL, it won't be accurate until a few months in.


----------



## 196nautique (Sep 23, 2005)

TSB will be negative until your CTL number is closer to your ATL.

If the CTL numbers are starting out at 0, it will be a while before enough information is in the program to give useful information.

When your CTL levels out, then the difference between CTL and ATL will give you an accurate TSB.


----------



## Ericv2010 (Nov 30, 2010)

Hmmm, alright. Makes sense (I think) - just a little unfortunate that I'll have to wait I guess.

Not all that critical I suppose since my first race isn't until April 22 and I won't even get outside to ride until mid-march or so.

I suppose one way around this is that I could specify starting values for both ATL and CTL (instead of letting them start at 0, like I've done) but the problem with this option is that I would have to guess, and I wouldn't even know where to begin with that.

I suppose it's better to just be a little patient and wait until enough data has accumulated for it to become useful. In the meantime, I'll continue with my Pz2 endurance / base building...

thanks,


----------



## kbiker3111 (Nov 7, 2006)

Ericv2010 said:


> Hmmm, alright. Makes sense (I think) - just a little unfortunate that I'll have to wait I guess.
> 
> Not all that critical I suppose since my first race isn't until April 22 and I won't even get outside to ride until mid-march or so.
> 
> ...


Its not that hard to guess, actually. From the rides you're doing, you can estimate what the average TSS/hour you are making. Figure out how many hours you rode the last couple months and thats a starting number for CTL. Underestimate a little to be safe and you're numbers should be pretty close. Just realize that since its not exact, the TSB numbers you get won't be exact either.


----------



## iliveonnitro (Feb 19, 2006)

You actually don't want a positive TSB until you are ready to race. Negative TSB typically means you are building fitness.


----------

