Hydration is a key factor in fatigue.
If you are doing everything correct eating well, sleeping, resting and still feeling fatigued and lacking focus at class take a look at your hydration. You should be drinking at least 8 ounces of water every hour, so for ease sake an average bottle of water every class.
Remember, we know the body is hydrated better during movement so drink continuously through class. Adding a pinch of salt and a squeeze of lemon juice will help speed up the hydration as both are full of electrolytes.
So stay drinking ?