Skyhawk 172/Cutlass 172
Flight Crew Private
Flight Crew Last 90 Days 2; Flight Crew Total 132; Flight Crew Type 132
Situational Awareness
Ground Event / Encounter Loss Of Aircraft Control; Ground Event / Encounter Object; Ground Excursion Runway
Human Factors
On second landing of a landing practice session. No clouds; wind variable (weather station reported wind missing last time I checked on approach); visibility >10 miles.  Normal approach speed (around 65 knots); full flaps; throttle idle.Aircraft floated on flare; held while airspeed was reduced; long float but touchdown before midfield. Landed slightly right of centerline. After the plane set for a moment; I began to apply the brakes to stop in time for taxiway Bravo. When I applied the brakes; the plane shuddered and then yawed to the right suddenly. Attempted to steer the plane back to straight; felt the plane wanting to tip to the left. Arrested the tip to the left; but plane started to enter a ground loop and tip to the right. While attempting to stop the ground loop and continuing to slow the plane with the brakes the aircraft continued to proceed to the right and left the runway. Plane came to a stop when it struck a taxiway light.I believe when I started braking that the plane had not fully settled on to the runway and that I induced a loss of control. I think if I had shut down the engine sooner I may have been able to stop the plane before it impacted the taxiway light. Letting the plane slow more on its own before I applied the brakes likely would have avoided the situation. A contributing factor was the light weight of the plane (I am used to flying with an instructor) and the very calm winds which lead to a high ground speed on landing.
C172 pilot reported a long landing and runway excursion due to loss of control under heavy braking.