Getting the balance right means a requirement to understand the principles behind the work you are putting in to improve your health and performance.
There are seven basic principles you will want to keep in mind:
specificity, individuality, progression, overload, adaptation, recovery and reversibility.
If you understand these principles, and practice them frequently your performance will improve.
For an individual to adapt to the specific demands of a training program and progress, recovery (insert “easy days” here also) is really KEY!
The body cannot repair itself without rest and time to recover.
Both short periods like hours between multiple sessions in a day and longer periods like days or weeks to recover from a long season are necessary to ensure your body does not suffer from over training or overuse injuries.
This is often neglected.
At a simplified level – that will vary with the individual – the more you train the more sleep your body needs, despite the adaptations you have made.
Get the balance right.