Training Peaks Metrics
You might have noticed strange numbers on your Training Peaks log and wondered what they mean. The main one is called TSS, which is a metric that TP comes up with based on your anaerobic or lactate threshold value: the maximal effort you can sustain for about 45 min. TSS stands for Training Stress Score, and is a number assigned to each workout based on either your pace (rTSS), heart rate (hrTSS) or power (tTSS). One hundred TSS points is equivalent to an hour spend at your anaerobic threshold. Remember that the anaerobic threshold is an effort you can sustain for 45-60 min. but not really any longer. So, an easy hour run is roughly 60. The TSS scores create the graph you see in your performance management chart (PMC), as well as the other metrics based on TSS.
Chronic Training Load (CTL) is based on the last 60 days of training, but more heavily weighted to the last two weeks; acute training load (ATL) is roughly the last 10 days of training, and the training stress balance (TSB) is a function of ATL, to show your “readiness to race” or perform. So, if you’ve been training consistently for many weeks without a break, the TSB would be a negative number and would show that you’re carrying fatigue that will not allow you to perform your best at a race or big objective. Here’s a great, brief video Training Peaks created to explain this.
If you’re new to Training Peaks, the numbers you see won’t be accurate until you’ve used the software for several months to accumulate enough data. When I first started using Training Peaks years ago, I had no desire to look at any of the metrics, as I think the subjective data is the most important thing, but over time, I began looking at it to reflect back on how training went, and saw that the metrics matched what I expected to see based on the subjective information and the modifications of the training plan. Now many years later, I use it more, but still don't want athletes to get bogged down in the numbers. The point of training isn’t to get the highest CTL number, but rather to improve your fitness to be able to do the goals you set out to achieve feeling healthy, confident, and ready for more.
