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Part 2: Training Stress Score—So What?

June 29, 2015

This is a continuation of my posts related to TrainingPeaks’ Performance Management Chart. It appeared recently on their blog. If you don’t use the PMC then this post probably won’t make sense to you. But I can tell you that it is the most effective single tool I’ve found for analyzing and planning an athlete’s training.

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In Part 1 I addressed the question posed by a TrainingPeaks subscriber of how high should his blue Chronic Training Load (CTL) line on the Performance Management Chart (PMC) be. I tried to explain that such a number can’t be proposed without knowing a tremendous amount of background info on the athlete. The answer depends on a lot of individual variables. The best way to use CTL is to pay attention to the trends over time. If CTL is rising then we can assume that fitness is also. The opposite is likewise true. That’s the primary thing we want to reap from the CTL.

But I suggested in that blog post that CTL can be used to determine how much Training Stress Score (TSS) you may aim for in any given workout. This is an imprecise “science” and is really just giving you a general target for each session. Here’s how to do it.

Typically athletes have three basic and general categories of workouts they do on a weekly basis. Let’s call them “hard,” “moderate,” and “easy.” What most of us do is follow a hard workout with an easy one and occasionally insert a moderate session. What should the TSS be for each of these general categories? Here’s a quick way to estimate them based on your CTL for any given day.

Hard workout—add 50 to 100% to CTL

Moderate workout—add 10-30% to CTL

Easy workout—subtract 20-30% from CTL

Let’s look at a couple of examples. In example #1 the athlete’s CTL is a rather high 100 (measured as an average of TSS for the last 42 days and expressed as “TSS/d”). Using the above ballpark values this athlete’s daily workout TSS categories would be…

Hard workout—150 to 200 TSS

Moderate workout—110-130 TSS

Easy workout—70-80 TSS

Example #2: How about an athlete whose CTL is 50? His or her three workout categories would be…

Hard workout—75 to 100 TSS

Moderate workout—55-65 TSS

Easy workout—35-40 TSS

Again, these are not meant to be unquestionable values. There may be days when you’re feeling great due to a few easy days or even days taken off from training and feel up to doing a hard session which produces a TSS greater than what is suggested above. Or the opposite is also likely to occur when you are too tired to do even a workout at 25% below your CTL. These are meant only to be ballpark numbers. They aren’t carved in stone and backed up by impeccable research. But they generally work.

In Part 3 I’ll discuss your PMC Training Stress Balance and how you can use real numbers there to manage your performance.

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