Kenyan marathon runner Lawrence Cherono has been handed a seven-year ban for breaching doping rules, the Athletics Integrity Unit (AIU) announced Wednesday. The 35-year-old runner, who won the Boston and Chicago marathons in 2019, provided an out-of-competition urine sample in May 2022 which revealed the presence of the prohibited substance trimetazidine. “The AIU has banned Lawrence Cherono (Kenya) for 7 …