Unsurprisingly, the COVID-19 epidemic has re-enforced people's quantified self-behaviors. According to Sensor Tower (2021), in Q2 2020, when the world faced the first wave of the COVID-19 epidemic, the number of quantitative apps (e.g. fitness, diet, and nutrition) installed surged by 530 million (Liu et al., 2021). Liu et al. (2021) argue that the emergence and spread of wearable devices (e.g., Apple Watch and Fitbit) means that consumers have become more comfortable quantifying their behaviour. Self-tracking devices for exercise and fitness can provide better control over one's health and body, reducing concerns about the usefulness of fitness programmes. According to Fitbit in 2020 news, research from Fitbit in Europe shows that people are indeed becoming more aware of their personal health and wellbeing thanks to COVID-19 (2020). Global data from Fitbit found an increase in sleep time for users worldwide from March to September 2020, a decline in overall steps and a decline in active minutes worldwide, but stress-relieving activities and activities that don't require a trip to the gym are increasing.

Bin	Frequency
Excellent: 90-100	35
Good: 80-89	57
Fair: 60-79	36
Poor: less than 60	2

Sleep Score
Mean	82.11538
Standard Error	0.790552
Median	84
Mode	90
Standard Deviation	9.048276
Sample Variance	81.8713
Kurtosis	0.855608
Skewness	-1.00051
Range	49
Minimum	51
Maximum	100
Sum	10757.12
Count	131

Our team analysed Fitbit users' management of physical stress in the post-epidemic period by capturing posts related to sleep scores and resting heart rate (RHR) on Fitbit Community from 2020 to 2022. There were 490 posts, with 187 users sharing RHR data in the forum. Searching for the keyword "Sleep Score", there were 135 posts related to the post-2020 period, with a total of 130 user-shared sleep score data in the forum.

We found that the average sleep score for users sharing data on Fitbit Community post-2020 is around 82.12. The majority of users have a sleep score of between 80 and 89, which is higher than the official Fitbit reference figure of 72 to 83. We believe that the long hours spent at home have made fitbit users more concerned about sleep quality. Jamie Wise (2021) argues that sleep can optimise the missing links in Fitbit users' health and that studying sleep habits can make it easier for users to achieve their personal health goals. According to Fitbit's research data, the average Fitbit user sleeps for approximately 6 hours and 38 minutes.

However, by analysing the data, we found that the average sleep time of Fitbit users who share their sleep on the forum between 2020 and 2022 is approximately 6 hours 55 minutes. This is consistent with the finding that users slept more and better during the Fitbit pandemic in 2020. We believe that the increase in the number of hours of sleep and sleep scores of Fitbit users is evidence that users are thinking more about the importance of sleep for a healthy life. As Targa et al. (2021) argued, flexibility in schedules due to social constraints in the context of COVID-19 outbreak-related events led to changes in wake-up times and bedtimes. Sleep is an important and highly sensitive behaviour.

Sleep Hour		SLeep Score
Mean	6.929385	Mean	82.18462
Standard Error	0.212615	Standard Error	1.083728
Median	7	Median	84
Mode	7	Mode	84
Standard Deviation	1.714158	Standard Deviation	8.737298
Sample Variance	2.938337	Sample Variance	76.34038
Kurtosis	3.37241	Kurtosis	3.470462
Skewness	0.404694	Skewness	-1.38838
Range	10.9	Range	48
Minimum	3	Minimum	46
Maximum	13.9	Maximum	94
Sum	450.41	Sum	5342
Count	65	Count	65

In terms of resting heart rate, the mean RHR data for Fitbit users based on our data analysis was approximately 61.8, with the vast majority of users' resting heart rates clustered between 50-90, consistent with research data provided by Fitbit in 2016. Of the 187 data points captured, there was only one static heart rate above 100bpm. In the range of 40–80 static heart rate, Fitbit users had a normal distribution of static heart rate. We believe that, against a backdrop of declining overall step counts for Fitbit users worldwide and declining active minutes around the world, the static heart rate of users is little changed from pre-epidemic by the increase in at-home exercise and stress-relieving activities among Fitbit users.

Resting Heart Rate
Mean	61.81818
Standard Error	0.944279
Median	60
Mode	60
Standard Deviation	12.91282
Sample Variance	166.741
Kurtosis	2.950319
Skewness	1.20932
Range	85
Minimum	39
Maximum	124
Sum	11560
Count	187

Bins	Frequency
less than 60	85
60-100	101
higher than 100	1
50-90	156

    

                                                            

                                                         

Number of groups	Group distance
14	6.071428571
Standard deviation	X
0.006483651	39
0.013324569	45.07142857
0.028992488	57.21428571
0.030696172	63.28571429
0.026053814	69.35714286
0.017727472	75.42857143
0.009669648	81.5
0.004228272	87.57142857
0.001482189	93.64285714
0.000416517	99.71428571
0.021952053	51.14285714
9.38318E-05	111.8571429
1.68455E-05	111.8571429
2.4533E-06	117.9285714
2.84729E	124