I have been using S-Caps for long training runs and ultra races since 2000 (I've run 85 ultras since 1997). S-Caps have always worked well for me, and I always carry a few extra which has helped save the races of several fellow runners through the years. Having S-Caps allows me to carry just water (no worrying about mixing up any special sports drinks.) Also, as a low-carb athlete for the last 7 years, it's important to me to keep electrolytes balanced. I appreciate that S-Caps have just what is needed with no extra ingredients.