Extreme exercise is good for you, right? No, not exactly. Research shows extreme exercise can cause chronic health problems such as inflammation, fatigued adrenals (your stress-handling glands), depleted hormones, weakened immunity and more. Recovery time is as important as the exercise itself. How do you know when it is too much? Workouts should leave you feeling energized. If you feel fatigued after exercising, you are overdoing it.