Let me start by saying my recommendation is coming from subject matter experience of my age, physique and experience.
The science I know is that the body requires the following sources of electrolytes - sodium, potassium, calcium, magnesium, chloride, phosphate , bicarbonate (HCO3), and sulfate. Sodium, potassium, magnesium and calcium are the four major electrolytes that maintain the body’s fluid balance. With good diet and a daily vitamin / mineral supplement this is all that is needed unless you are undergoing extreme physical activity resulting in high fluid loss through sweat. Even then my experience is that the level of high physical activity needed to require electrolyte supplementation or boosting is not as frequent as most of us think. With good diet and consistent hydration throughout the day I don’t typically need to supplement even under very heavy activity. It doesn’t mean I don’t supplement from time to time when I don't get good nutrition or hydration but I feel it is important to know when to supplement rather than just supplement because I think I need to. I try to be conscious of my urination and what it looks like. If it is a pale yellow or straw color I know I am maintaining good hydration and electrolyte levels and don’t typically need to supplement even under the highest levels of activity. If it is dark in the morning or dark any time during the day I know I need to increase hydration and supplement the big four. When engaging in an activity that will require re-hydration with high levels of perspiration I will try to hydrate with a half a liter of water a few hours prior to that activity and maintain hydration during constant activity with a quarter liter or so every 20 minutes to half hour. Now let me say I engage in some very strenuous activities over several hours to several days, and only during times that I notice darker urine or the onset of weakness, spasms, side stitches, dry mouth or achy joints do I use a supplement. When I do, I like “Enduro Packs” - It’s an all-natural liquid electrolyte supplement with no sugar added. I mix it with my water during high activities when those symptoms arise. I also will drink a Gatorade to do the same thing I just don’t like all the sugar. Don’t get to hung up on the hype. . . Look for a supplement that replenishes the four major electrolytes and forget all the other nonsense they may add and that may increase cost.
Hydrate and eat right and I feel you will be able to endure extreme activities without supplements.
