Someone just pointed out to me that I forget to explain what "TSS" is in my post yesterday. Sorry about that. This gets rather hairy with further definitions needed, which I'm not going to get in to. Here it is...
TSS. Training Stress Score. In WKO+ software this is an indicator of how hard a workout is. The formula for TSS is:
TSS = [(s x NP x IF) / (FTP x 3,600)] x 100
where s is workout duration in seconds, NP is normalized power (or pace in running), IF is intensity factor, FTP is functional threshold power (or pace in running), and 3,600 is the number of seconds in an hour.
A cumulative, running average of workout TSS is expressed as CTL (usually a 42-day average). This is what I was referring to yesterday when speaking of the rate of increase in cumulative TSS as perhaps to be great for the rider who asked the question.
I hope that helped some, but I expect if you don't use a power meter, runner's GPS or WKO+ software then you have an even deeper level of confusion. The best way to understand this stuff is to train with such a device and use WKO+ to analyze your training.