In 2013, researchers of the University of Calcutta, India, studied the effects of changing lunar cycles on the cardiovascular systems of male university students. During new moons and full moons, blood pressure dropped by around 5 mm Hg. A step test was also given to the study participants. New or full moons resulted in lower heart rates and blood pressures. Additionally, when the new and full moons came, their hearts returned to normal faster. According to this study, humans were more physically effective at full and new moons.
Other studies have found no significant difference in athletic performance during lunar phases, including a 2020 study that looked at male athletes. Researchers found that lunar cycles did not affect blood pressure in people with type 2 diabetes, but they did affect blood sugar levels and heart rate.