“These traits no longer increase, despite further continuous nutritional, medical, and scientific progress,” said Jean-François Toussaint, a physiologist at Paris Descartes University, France, in a press release. “This suggests that modern societies have allowed our species to reach its limits.”

For the study, published in the journal Frontiers in Physiology, a team of French scientists, including Toussaint, from a range of fields analyzed 120 years worth of historical records and previous research to gauge the varying pace of changes seen in human athletic performance, human lifespan and human height. While, as they observe, the 20th century saw a surge in improvements in all three areas that mirrored industrial, medical and scientific advances, the pace of those advances has slowed significantly in recent years.