SAN FRANCISCO (KRON) — If you’re struggling to get through your workouts after recovering from COVID, you are not alone, according to a new study from University of California San Francisco.

In a study published in JAMA Network on Wednesday, researchers with UCSF and Zuckerberg San Francisco General Hospital reviewed 38 studies which tracked exercise performance of participants who had previously been infected with COVID. The analysis focused in on nine studies comparing exercise performance of people who had recovered from COVID to exercise performances of people who had systems that were consistent with long COVID.

According to UCSF, the average age of participants in the study was between 39 and 56 years old, and the average body mass index ranged from overweight to obese. The findings showed that within the group suffering from long COVID, people may experience reduced oxygen extraction in the muscles and irregular breathing patterns. Those with long COVID may also experience a limited ability to increase their heart rate during exercise in order to keep up with cardiac output.

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So what does this mean for those suffering from long-COVID symptoms? According to one of the study’s authors, Dr. Matthew Durstenfeld, the illness can age people in terms of exercise capacity or measured in metabolic equivalent tasks (METs).

“This decline in oxygen peak rate would roughly translate to a 40-year-old woman with an expected exercise capacity of 9.5 METs, dropping to 8.1 METs, the approximate expected exercise capacity for a 50-year-old woman,” he said.

Dr. Durstenfeld says another way to look at it is that a person who regularly played doubles tennis before becoming infected with COVID may need to transition to playing golf or stretching exercises instead. He says those who swim laps may find that more low-impact aerobic activities are a better match, but he clarified that this is an “average” experience.

“Some individuals experience a profound decrease in energy capacity and many others experience no decrease,” he said.

Senior author of the paper, Dr. Priscilla Hsue, says that further studies, “should include long-term observational assessments to understand the trajectory of exercise capacity.”