Nightly Recharge™ FAQs
After how many nights will I get the feedback?
You get your Nightly Recharge status after three nights (three successful measurements). This is how long it takes to establish your usual level. Before you get your Nightly Recharge you can view your sleep and ANS measurement details (heart rate, heart rate variability and breathing rate).
How can breathing rate be measured from the wrist?
Breathing causes variation to the heart's beat-to-beat intervals which can be measured optically from the wrist.
How to use the night-time only option in Continuous HR tracking
If you want to save battery and still use Sleep Plus Stages, you can set the continuous heart rate tracking to be on only at night from your watch's settings. Go to Settings > General Settings > Continuous HR tracking and select Night-time only. Set heart rate tracking to begin at the earliest time you might go to bed.
How does stress affect the feedback?
The effects of stress on your body can be seen in the functioning of your autonomic nervous system. After a demanding day, it takes more time than usual to switch from activation mode to relaxation mode, which is reflected in the ANS charge.
In general, when you are under stress your heart rate and breathing rate are higher than usual, and heart rate variability is lower than usual. Other factors that prevent efficient ANS recovery during sleep include hard physical exercise, intense emotions, alcohol, fever and inflammation.
Stress can also have a negative effect on the quality of your sleep.
Should I aim to always have a green Nightly Recharge status?
We are comparing your last night to your usual level. Combining training with work, family and other commitments is sometimes demanding and there may not always be enough time for recovery. That's why it’s normal for your Nightly Recharge status to vary. ANS and sleep measures are highly individual, and they are interpreted against your individual (night-to-night) variation. For this reason you should also see red and orange in your battery every now and then.
Why is Nightly Recharge measured during the night?
Sleep is a natural period for recovery. Sleep is also the best time for an automatic measurement. During 24/7 automatic tracking, nightly sleep is the best period to unobtrusively measure and interpret the functioning of your autonomic nervous system. It is a somewhat controlled and repeatable condition in terms of signal quality, posture, mental state, environment and time of day.
Why is ANS charge calculated from the first part of the night, and sleep from the whole night?
The first hours of sleep reflect recovery more sensitively than measurements averaged from a whole night's sleep. The first hours of sleep are also important for physical recovery as most of your deep sleep occurs then.
How does very intensive exercise affect my Nightly Recharge?
After very intensive exercise during the day, it takes more time than usual for the body to calm down. If you exercise late in the evening it may be difficult to fall asleep. Your sleep charge may be lower than usual (due to disturbed sleep) and/or your ANS charge may be lower than usual leading to a poor Nightly Recharge status. Heart rate and breathing rate are higher than usual, and heart rate variability is lower than usual.
Other factors that prevent the ANS from recovering during sleep as efficiently as usual include mental stress, intense emotions, alcohol, fever and inflammation.
How does alcohol affect my recovery?
Alcohol prevents your ANS from recovering as efficiently as usual and may also disturb your sleep.
Does my fitness level influence the results?
Your ANS charge is based on your usual level. Your values are not compared to others’ values. That's why your fitness level does not directly affect ANS charge. When speaking about absolute numbers, a low heart rate and a high heart rate variability are generally linked to high cardiovascular fitness.
Why I did not get sleep tip this morning?
You get a sleep tip, when you didn't sleep as well as you usually do. Sleep tip is not given every day.