More days of either aerobic or strength exercise were associated with lower eGFR. eGFR is a measure of the rate that the kidneys are able to filter blood that is based on creatinine in the blood, along with age, race, and sex. While physical activity has been positively associated with kidney function  eGFR may be higher in athletes following exercise because of higher creatine metabolism, especially for athletes with larger muscle mass . However, eGFR may be temporarily decreased in the day following exercise  and has been shown to be lower in some endurance athletes and team sports athletes .