Cinder/dirt/small gravel tracks were over one second slower per lap (1 to 1.25 seconds per lap), especially U.S. 440 yard tracks. So-called U.S. 440 cinder tracks were designed when 220 yard dash on straightaway was a standard high school and small college event. U.S. 440 yard cinder tracks were designed with 100 yard curves. There is a bit of energy return with synthetic tracks. There was no energy return on so-called cinder tracks. Even the so-called maintained tracks had ruts. One's knee would buckle or ankle would twist. Lastly, one wore longer and heavy spikes. Greater foot weight slowed one down. To believe those tracks were not slow would mean humans have evolved since the days of Mal Whitfield.