The easy way to aerate your lawn.
Spring-loaded spikes create 150 slits per sq m.

Safety
To safely use a push-along lawn aerator, first inspect the equipment for damaged parts and clear your lawn of debris. Water the soil 1-2 days before aerating so it's moist but not soggy. Wear closed-toe shoes and gloves for protection. Grip the handle firmly with both hands, keeping your back straight and using your legs to push rather than straining your back. Walk at a steady pace behind the aerator, applying even pressure and letting the weight of the machine drive the spikes into the soil. Take extra care on slopes or uneven terrain, and avoid pulling the aerator backward toward yourself. After use, clean the spikes thoroughly and store in a dry place.