If you are accustomed to tracking a weekly TSS table, Xert is a lot more flexible than that.
The Training Pacer represents a moving weighted average of XSS over a 7-day period.
Perhaps this article explains it best –
I had an XSS Training Surplus of X yesterday but today I have a big deficit of Y. What’s going on? – Xert
The daily deficit/surplus indicates current pts below/above the neutral position (Noon) on the Training Pacer. A deficit isn’t necessarily “bad”. Try to keep the pacer needle within the 11am-1pm position and you’re on track to maintain your improvement rate (IR).