The invention provides compositions comprising Enol for delivery to a muscle. Further, the invention provides a method for normalizing blood glucose in a subject with elevated blood glucose, comprising administering to the subject enolase 1 (Enol), thereby normalizing blood glucose in the subject. The invention also provides methods of treating one or more conditions including impaired glucose tolerance, insulin resistance, pre-diabetes, and diabetes, especially type 2 diabetes in a subject, comprising administering to the subject enolase 1 (Enol), thereby treating the condition in the subject. In certain methods of the invention, the Enol is delivered to muscle.