Complex sentence: Martin has been instrumental in the introduction of the Coerver ® Coaching Program in fifteen countries during which time he has worked with recreational players, elite players, professional clubs, National Federations and International Governing bodies.
Split into simpler sentences: Martin has been instrumental in the introduction of the Coerver Coaching Program in fifteen countries. In this time he has worked with recreational players, elite players, professional clubs, National Federations and International Governing bodies.