ANS Balance

The Autonomic Nervous System (ANS) controls almost all of the body's "automatic" processes, such as regulating blood sugar, blood pressure, energy, digestion, sexual function, tissue repair, and more.
There are two main branches of the ANS: the Parasympathetic Nervous System (PSNS) and the Sympathetic Nervous System (SNS). The PSNS primarily controls the body's recovery systems while the SNS primarily modulates the stress response. The ANS balance indicates the relative balance between these two sub-systems, thus indicating the balance between recovery and physiological stress (both physical and mental).
Knowing the relative balance of the ANS helps you better understand the current state of your body and determine the best course of action towards reaching your goals without working against yourself.
ANS Balance and the ﻿Daily Readiness insights both require at least two days of data as input. If it's your first day taking a reading, you'll receive a value of null for both of these scores. Check out the input requirements and output table below for more details!
Input RequirementsIf you're using your own device or an external device to connect to Spren API, follow the input requirements below. If you're using Spren Vision to connect to Spren API, you will just pass along the readingData object from the SDK directly to Spren API. See more information in the Spren API Overview.
Input
Data Type
Description
ibi
array of int
An array for inter-beat intervals; at minimum, 60 inter-beat (R-R) intervals are required.
Input Requirements
Example Input JSON
Recommendations for increased accuracy
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JSON
|
{
    "ibi": [
        1096,
        1056,
        1040,
        1052,
        994,
        959,
        931,
        910,
        887,
        867,
        871,
        920,
        1259,
        1188,
        1180,
        1142,
        1113,
        1052,
        999,
        976,
        978,
        973,
        978,
        951,
        957,
        998,
        1037,
        1052,
        1020,
        986,
        1025,
        1039,
        1039,
        1003,
        959,
        969,
        991,
        981,
        968,
        945,
        983,
        1042,
        1061,
        977,
        956,
        965,
        971,
        983,
        959,
        966,
        972,
        970,
        947,
        944,
        972,
        984,
        949,
        915,
        957,
        959
    ]
}    
{
    "ibi": [
        1096,
        1056,
        1040,
        1052,
        994,
        959,
        931,
        910,
        887,
        867,
        871,
        920,
        1259,
        1188,
        1180,
        1142,
        1113,
        1052,
        999,
        976,
        978,
        973,
        978,
        951,
        957,
        998,
        1037,
        1052,
        1020,
        986,
        1025,
        1039,
        1039,
        1003,
        959,
        969,
        991,
        981,
        968,
        945,
        983,
        1042,
        1061,
        977,
        956,
        965,
        971,
        983,
        959,
        966,
        972,
        970,
        947,
        944,
        972,
        984,
        949,
        915,
        957,
        959
    ]
}    
﻿
Minimum 60 inter-beat intervals (R-R intervals)
Measurement was taken "at rest," not during exercise nor during a stressful period
No more than one missing inter-beat interval per 60 seconds of data
No more than one major artifact from movement or sensor disruption per 60 seconds of data
A minimum of 50Hz sampling rate for PPG signals or 250Hz sampling rate for ECG signals
Note: If you are using the Spren Vision SDK to collect the measurement data, then these additional recommendations 
OutputsANS Balance is returned as an integer on a scale of 0 - 5 as a part of the output response JSON, with the key ansBalance. The definition and additional contextual information of each output is outlined below in the table. ANS Balance can add an additional layer of context to an existing insight that's being served to users.
Output
Definition
Example Color Indicators
User Tips
null
Insufficient data
Grey
Not enough data present to calculate ANS balance.
1
Strong imbalance towards SNS activity.
Red
The body is experiencing deeper levels of stress or fatigue. To avoid over training or over stressing it is highly recommended to prioritize rest.
2
Moderate imbalance towards SNS activity.
Yellow
Indicates greater than usual stress (from all sources). Energy levels may be elevated. For long term results, consider lighter exercise and/or reducing stressful activities.
3
Relatively balanced PSNS and SNS.
Green
The body is typically the most flexible and capable when the ANS is balanced.
4
Moderate imbalance towards PSNS activity.
Yellow
Recovery activity is slightly elevated. Energy levels may be lower. This state is often correlated with overreaching in training or fighting off mild or early illness.
5
Strong relative PSNS activity.
Red
Indicates excessive recovery activity, often in response to cumulative stress or elevated immune system activity.
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Design ExamplesThe most common display of the ANS Balance is using a color-indicated scale, although the ANS Balance display is completely customizable to match the branding and user experience goals of your app.
Examples displaying the ANS Balance in an app card.
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Example text for an in-app tooltip or information drawer to provide user education about the ANS Balance:
The autonomic nervous system (ANS) controls almost all of the body’s “automatic” processes. It regulates bodily functions such as heart rate, blood sugar, blood pressure, temperature, energy, digestion, sexual function, tissue repair, and more.
There are two main branches of the ANS: the parasympathetic nervous system (PSNS) and the sympathetic nervous system (SNS). The SNS primarily controls the body’s “fight or flight” stress response while the PSNS modulates the body’s “rest and digest” recovery systems. The two branches work in conjunction to provide input to your body at all times, in response to perceived stressors.
The ANS Balance indicates the relative balance between these two branches, thus indicating the balance between recovery and physiological stress (both physical and mental).
Knowing the relative balance of the ANS helps you better understand the current state of your body and determine the best course of action towards reaching your goals without working against yourself.
﻿
﻿

TABLE OF CONTENTS

Input Requirements

Outputs

Design Examples

Input	Data Type	Description
ibi	array of int	An array for inter-beat intervals; at minimum, 60 inter-beat (R-R) intervals are required.

Output	Definition	Example Color Indicators	User Tips
null	Insufficient data	Grey	Not enough data present to calculate ANS balance.
1	Strong imbalance towards SNS activity.	Red	The body is experiencing deeper levels of stress or fatigue. To avoid over training or over stressing it is highly recommended to prioritize rest.
2	Moderate imbalance towards SNS activity.	Yellow	Indicates greater than usual stress (from all sources). Energy levels may be elevated. For long term results, consider lighter exercise and/or reducing stressful activities.
3	Relatively balanced PSNS and SNS.	Green	The body is typically the most flexible and capable when the ANS is balanced.
4	Moderate imbalance towards PSNS activity.	Yellow	Recovery activity is slightly elevated. Energy levels may be lower. This state is often correlated with overreaching in training or fighting off mild or early illness.
5	Strong relative PSNS activity.	Red	Indicates excessive recovery activity, often in response to cumulative stress or elevated immune system activity.