What is WHOOP Strain?
Strain measures the cardiovascular load that your body takes on during a given day or training session. Strain uses your physiological baselines to quantify how a given training stimulus taxes your body internally.
Strain uses a scale from 1 to 21. The closer to 21 you get, the more stress you put on your body.
How is Strain calculated?
Day Strain starts accumulating from the moment you fall asleep and resets every sleep cycle. Your Day Strain score represents the total stress load that your body takes on throughout the day, on and off the field.
Activity Strain is calculated by combining the weighted time you spent at various heart rate zones throughout a training session. That way, you can compare specific efforts within specified time periods throughout sessions.
How are Strain and Recovery related?
Strain takes your Recovery metrics into account like resting heart rate. This means that on days when your Recovery is low, you may fatigue quicker and Strain will accumulate easier. Monitoring Strain based on your Recovery can keep you performing at your peak recoverable volume for extended periods of time. Additionally, on days when you record levels of Strain that are higher than normal, monitor your score and pay close attention to your Recovery score.
Strain Coach recommends target exertion levels based on how recovered your body is. When you start an Activity, WHOOP shows you in real time whether you can push harder, you’re overdoing it, or you’ve reached your goal.
Strain scores in the gym
An intense lifting session may not register as high Strain, but don’t get discouraged. This does not mean that your body isn’t working hard. Anaerobic training will show up in other aspects of your physiological data like HRV and Recovery the following day.
Does monitoring training load really work?