This article review commonly asked questions regarding WHOOP Data.
Why should athletes care about HRV?
High HRV is a sign that your body is capable of adaptively responding to its environment. When HRV is low, the nervous system is sending unequally strong signals to the heart. Sometimes this is a necessity; in cases of immediate threat, we want our bodies to put 100% of our resources behind eliminating the threat and to temporarily divert resources away from non-emergency operations.
In non-emergencies, HRV reflects the extent to which your body is “distracted” with other physiological demands, such as musculoskeletal recovery, stress, illness, and fatigue. This is important for athletes because any resources going to these distractions cannot be used for athletic activities. An athlete who cannot put 100% of his resources into his sport is therefore at a disadvantage compared to competitors who can.
To learn more, check out Ultimate Guide to HRV.
What does ‘Optimal Training’ mean?
‘Optimal Training’ refers to the ideal amount of Strain to increase fitness while avoiding burn-out. In physiological terms, this region has typically resulted in consistent HRV levels the next day.
How do I use the Training State graph?
The Training State graph plots your daily Strain and Recovery values relative to ‘Optimal Training’. ‘Optimal Training’ refers to the ideal amount of Strain to increase fitness while avoiding burn-out. In physiological terms, this region has typically led to higher HRV levels the next day. When analyzing your training state, it’s important to consider the grouping of daily values.
For example, if the majority of a week’s daily values are above the ’Optimal Training’ curve, it’s likely that this week resembles an ‘Overreaching’ week. Typically, weeks like this result in a decline in HRV and short-term fatigue. Conversely, if the majority of a week’s daily values are below the ’Optimal Training’ curve, it’s likely that this week is a ‘Restorative’ week; producing an increase in HRV.
Why is the sum of my Activity Strain lower than my Day Strain?
Strain is the total cardiovascular load that occurs throughout the course of the day. Strain is not linear in the sense that WHOOP simply adds the total of your Activity Strain's together.
Strain is scored on a 0-21 scale and within that, there are two separate kinds of Strain. First, is your Day Strain which is the overall number that you are going to see within your Strain score. Day Strain is a culmination of the entire day’s Strain, which includes Activity Strain.
Second, is your individual Activity Strain which scores the workouts and activities completed within the day. Activity Strain only applies to a shortened amount of time within the day. Two Activity Strain scores of 10 will not equal 20, because Strain is not linear. Below, you can see that it is easier to get a 10 Strain than a 14 Strain. Therefore, two Strain scores of 10 will not equal 20, but instead, perhaps closer to a 13, which will be reflected in Day Strain.
If you measure a specific Activity Strain, the Strain for that time period starts at 0 and goes up from there. Therefore, Day Strain is not the total of your Activities instead it is your total Strain for the day (not a linear calculation but rather, logarithmic). It is possible mathematically, due to logarithmic growth, to end up with activity strains that are higher individually than your total day strain.