Women’s American 5,000- and 1,500-meter record holder and Olympic contender Shelby Houlihan is banned from competing for four years after testing positive for steroids, and now Sha’Carri Richardson, America’s fastest woman, is benched for a month — and thus forced out of the Tokyo Games — for failing a drug test for marijuana. Wherever the blame lies, and however intentional or unintentional the offending acts, these cases remind us of the enduring presence of performance-enhancing and illegal substances in sports. Doping shreds public trust in athletics and in each affected sport — not just in countries known for concocting systematic doping measures, but right here in the United States. Even worse, offenders take money, fame and glory away from clean competitors. With the Olympics drawing near, today’s Daily Dose digs deep into the murky world of performance enhancement and highlights how cutting-edge, controversial technologies are upending the sports world.