By Jane Wright
You may have spotted a Fit by Sonic Boot Camp in action on Streatham Common on Saturday afternoons recently. Marina and Liene started Fit by Sonic a year ago with the aim of offering incredible value for money and getting results for their clients. Classes start from £3.00 - probably the cheapest Pay As You Go classes in the South London. They even offer a price-match promise, plus loyalty cards and incentives to help make all their service affordable.