Hi Laurie,
Just to provide a little more detail on what Coach AJ said (although the TP metrics are highly influenced by your LT and HR zones):
“Form” (aka Training Stress Balance) is the difference between your Acute Training Load (7 days) and your Chronic Training Load (42 days). Simply put, it measures whether you’ve been putting an increased or decreased training stress on your body over the past week. While AJ should be the main guidance on this, Joe Friel (coach, creator of training peaks) says that TSB/Form should be between -10 and -30 for the majority of your base and build periods (with an increase closer to 0 during recovery weeks). It will also increase during the taper phase, but how high it goes is a decision made on an individual basis. Link to Joe Friel’s article here.
Note that the goal here is not to drive your TSB down as low as possible by piling on lots of training. Its a trap that a lot of triathletes fall into (aka Me) that often leads to injury/burnout. The goal is to consistently keep your training going throughout the racing year, with slight and gradual increases as needed.
While some people find it really helpful to quantify how fatigued they are, you could also get this info based on how you feel during workouts or in the morning. For example, if you are feeling extra groggy a few days in a row, you might need some extra sleep–don’t need TP to figure that out.
Also of note, while TSB will change based on how much you’re training, it doesn’t account for lack of sleep or other stressors (work, family, etc.). So there’s definitely a need to play it by ear to some degree.
In short: Get a handle on your HR/pace/power zones first, then (with approval from Coach AJ) keep it slightly below 0 as you move towards your race.
