Endurance improvement

For the last two years, I was struggling to work out in the GYM aggressively like I used to be several years ago, although my diet was responsibly clean, I was still feeling fatigued, exhausted, and running out of energy after the first 15-20 of the workout! My abs muscles were getting cramp really bad just by doing 10-15 reps of sit-ups! Then when I started watching Dr. Berg's videos, I learned that I'm missing few things in my diet: Vitamin E which is gonna help me strengthen my muscles, and electorate components for my muscles cramp. I started taking 1 pill of vitamin E pre-workout and I immediately started seeing a good difference regarding my power endurance. I also bought electrolyte powder from Dr. Berg's store to help me out of getting my body with the necessary minerals such as Potassium, Sodium, and Magnesium.