People who later experienced persistent shortness of breath or fatigue after a COVID infection were already taking significantly fewer steps per day and had a higher resting heart rate before contracting the virus, according to a CSH study published in npj Digital Medicine. This may indicate lower fitness levels or pre-existing conditions as potential risk factors

Between April 2020 and December 2022, over 535,000 people in Germany downloaded and activated the Corona Data Donation App (CDA). Of these, more than 120,000 voluntarily shared daily data from their smartwatches and fitness trackers with researchers, providing insights into vital functions such as resting heart rate and step count.

“These high-resolution data served as the starting point for our study,” explains CSH researcher Katharina Ledebur. “We were able to compare vital signs in 15-minute intervals before, during, and after a SARS-CoV-2 infection.”