You can park at Kuilpad 1, go straight ahead and go across the bridge, walk straight forward through the park (about 4 minute walk) until you're at the field where you can find the trainer.
At the entrance of the Darwinpark, Brikstraat 67 at Zaandam.
At the parkinglot near John Lennonstraat 165 in Zaandijk
At elementary school "De Meander", Kaaikhof, Assendelft
Behind the Albert Heijn at the Rosariumpark side
Agmar van der Ven