Like many Kenyan elite athletes, Hosea first began running while traveling to and from school. In 2004 he came second in the junior race at the
Kenyan Cross Country Championships and was later selected for the world championship team. As a
cross country junior athlete he came sixth at the World Cross Championships that year, improving to fourth place the following year. Macharinyang made his first appearances on the
track in 2004 and after a fourth place over
10,000 metres at the
2004 World Junior Championships in Athletics, he went on to take the
silver medal at the 2005
African Junior Athletics Championships. He moved up to the senior ranks at the
2006 IAAF World Cross Country Championships and helped Kenya to the team medal with his sixth-place finish in the long race. Further team golds came at the 2007 and 2008 events, where he was fifth and eleventh overall, respectively. He won the 2007
Great Edinburgh Run and made his
half marathon debut at the 2008
Stramilano, finishing fifth. An
Achilles tendon injury in the middle of 2008 interrupted his career and after five straight international selections for the World Cross Country Championships, he missed the 2009 edition. He came ninth at the
2010 World Cross but missed out on a team placing as the fifth Kenyan finisher. He ran a half marathon best of 1:01:38 hours for fifth at the 2010
Udine Half Marathon. A tenth-place finish at the
2011 IAAF World Cross Country Championships saw him again finish outside of the Kenyan team. He was fourth at August's
Beach to Beacon 10K and in September he entered the
Philadelphia Half Marathon, but was three minutes behind the winner
Matthew Kisorio. He returned to cross country in December and finished third at the
Cross de la Constitución. ==Achievements==