Downhill mountain biking emerged in the 1960s in California as people rode their bikes down hills at high speeds. The sport has evolved significantly since then in equipment and rider skill level, with bikes now specially designed for downhill racing. Major competitions began in 1990, and world-class riders like Sam Hill now train intensively from a young age to succeed at the elite level, where riding requires strong bikes, protective gear, and risk-taking to handle the challenges of fast, technical downhill courses.