My character is falling and standing/jumping at the same time?

if my players y velocity is less than -1 then fall is true. if my players y velocity is greater than or equal to 0 then stand = true. I have a debug log showing when my player is falling or standing. However they are both counting when either action is performed.

 public float slideFriction;
     public float normalFriction;
     public Collider2D coll;

 void Start () 
     {
         coll = GetComponent<Collider2D>();
         fall = false;
         stand = false;
     }

 void FixedUpdate();
             playerVelocityY = Player.velocity.y;
             if (playerVelocityY >= 0f) 
         {
             stand = true;
             
         }
         if (playerVelocityY <= -1f)
         {
             fall = true;
         }
                 if (fall)
         {
             Debug.Log ("FALL");
             coll.sharedMaterial.friction = slideFriction;
         }
         if (stand)
         {
             Debug.Log ("JUMP / STAND");
             coll.sharedMaterial.friction = normalFriction;
         }

When falling i want my characters friction to become slideFriction (for slowed wall sliding) and when jumping or standing I want my characters friction to become normalFriction (so that when I jump against a wall I have very little resistance against my jump).

My jumping code is fine the only problem is this. Please help. Thanks in advance.