He was a former spokesman for NordicTrack exercise equipment. In 2001 he came out with the in-home program Power 90. In 2004 he created P90X or Power 90 Extreme. To date, over four million copies of P90X had been sold. In 2011 he released P90X2 and in 2013, P90X3. His first book Bring It! was published in 2010. In 2014 Horton came out with P90, which was billed as on “on switch” to fitness.