Fitness Training in parks

Im quite worried about the amount of group fitness classes that are starting up in our local parks , certainly in my park they now hos one on both a Saturday ans Sunday morning ... the time when most people want to take their dogs out. While I understand that there are lots of 'fitness' related drives around , and get people moving incentives , I also think that there should be a limit on the number of occasions a park is used for them. After all , the organisers aren't doing this for nothing , they are charging a reasonable about of money for their services - these are businesses that are moving into our parks. Whats your views? , Parks for recreation? or should we be more accepting of fitness classes and businesses using them? Here's an interesting article from the BBC regarding councils charging fitness instructors for the use of parks http://www.bbc.co.uk/news/uk-16656288