What do the Optimized Training Stress (OTS) values mean?

Optimize Training Stress (OTS) measures the amount of stress placed on your body from your power data.  OTS is used in our new Optimize app.

OTS is an improved version of TSS (Training Stress Score), which has been widely used for a number of years.

So why a new metric? Two reasons:

  1. OTS accounts for the fatigue that accumulates during an exercise session. Your long ride feels harder during the fourth hour than it did during the first hour because your threshold has decreased during the ride. Not all four hours are counted the same - even if done at the same average power - because they are not the same.
  2. OTS accounts for periods of coasting and does not provide training “credit” for that time.

These improvements enable coaches and athletes to measure training load and balance recovery with greater precision.


Here is an overview of common OTS scores from rides, workouts, and races — and indications on how much recovery you may need from each.

OTS and recovery time

Recovery times will vary depending on your age, nutrition, lifestyle, your sleep and HRV values as recorded and incorporated into your Optimization Score in Optimize.

But you can approximate how much recovery you will need based on your OTS score. Here are some example recovery time frame scenarios presuming your sleep and HRV fall within your normal baseline ranges.

In broad strokes, pedaling constantly for an hour in zones 2 /3 will generate 40-60 OTS.

0 - 125 OTS

Generally speaking you can recover from a ride that generates 0-125 OTS with a good night’s sleep and HRV values.

126 - 200 OTS

Younger athletes can likely recover from 126-200 OTS rides with a good night's sleep, but older athletes may need additional recovery. As always, listen to your body and use your data with your training plan.

Refer to your daily Optimization Score for further guidance with your training and recovery balance. It is likely your Optimization Score may be in the red, but not so much that you need a recovery day, rather an easier, shorter, zone 2 day.

OTS scores

201 - 250 OTS

Values between 201 - 250 will need additional recovery time for masters athletes. Younger athletes tend to bounce back quicker and are able to train meaningfully if not the next day the next. After an OTS between 201-250 you may be in the red (121 - 150) but you also may be further in the red (151 - 180) Use your recovery metrics (& Optimize) with your training plan to decide what to do for training. 

251 - 300 OTS

For big days like this, more than one recovery day will be needed for masters athletes. Some masters athletes may be fine to train after one rest day; others may need two or more. Use your Optimization Score and your training plan to guide your training following large OTS rides like this.

301 - 400 OTS

Multiple days off will be necessary for masters athletes. Expect to be all the way in the red following training rides and races that put you over 300.  These the 5-7 hour training rides and events. 


401 - 500 OTS

Five-hour training rides, gran fondos and gravel events will generate OTS values north of 400 and warrant recovery blocks of two to three days if not a full recovery week. Use your Optimization needle to know when you are recovered to train again. Masters athletes, expect a minimum of two - four days to recover.

500 + OTS

500+ OTS is epic territory for 10+ hour events and rides like Unbound Gravel.  In our experience recovery duration is measured in weeks, plural.

About Frank Overton

Frank founded FasCat Coaching in 2002 and has been a full time cycling coach since 2004. His educational background includes a Masters degree in Physiology from North Carolina State University, pre-med from Hampden-Sydney College. Frank raced at a professional level on the road and mountain bike and currently competes as a "masters" level gravel and cyclocrosser. Professionally Frank comes from medical school spinal cord research and molecular biotechnology. However, to this day it is a dream come true for Frank to be able to help cyclists as a coach.

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