Personally my most common drink when exercising is high quality water plus high quality sea salt. However, people seem to feel that is not enough to optimize their performance. I steer people away from sports drinks because they contain a lot of junk which is not beneficial to health or performance. Anyway, a recipe came my way from a practitioner who works with athletes and I adapted a bit for a start point template:

• 2-4 parts high quality water (filtered, mineral, spring)
• 1 part high quality coconut water
• pinch of high quality sea salt
• squeeze of organic lemon or lime
• some liquid amino acids
  • Biotics Research – Amino Acid Quick-Sorb
  • Lumina Health / NuScience – Cellfood
  • Coconut Secret / Leslie’s Organics – Coconut Aminos
• if endurance exercise greater than 2 hours then optionally add small amount of raw maple syrup