Working hard for months and then hitting a plateau is no fun for any one. How you deal with it is what matters most. They way I have seen plateaus is when your body gets used to what you are doing and is looking for more of it. It might be as simple as increasing your distances when running. Or maybe even increasing the weight you are lifting a little each week. Your body craves the work! Your body wants to be challenged. So just go for it. So these plateaus also happen with weight loss. You might be trucking along losing a pound or two a month and feel great. Then BAM! Nothing! When this happens to me, it is a sign that I need t adjust my eating, workouts, and RESTING. All of which are the keys to a healthier life.