Ski Tips #1- The downside of building strong quads
***Stop focusing on building stronger quads*** in your winter preparation.
These muscles are already strong and they will be triggered all winter long.
What you should be doing is training the antagonist muscles / posterior chain.
You can push the envelop even more by making them stronger than your quadriceps.
As long as the winter will go on, the balance of the agonist/antagonist muscles will come back.
This helps prevent many knee injuries due to super strong quads and weak hamstrings and glutes.