Complex sentence: Potchefstroom is the only place in the world with a perfect balance between altitude training and quality training at 1,400 m. Another reason for the favoured conditions is that Potch (shortened name) has no large factories, which means that the city has excellent air quality.
Split into simpler sentences: Potchefstroom is the only place in the world with a perfect balance between altitude training and quality training at 1400m. The fact that Potch (shortened name) has no large factories which means that the city has excellent air quality.