A 2nd to Arnold's vote for SaltStick Caps.
Some years back I cramped before A-Frame during the Ascent. Even now, the literature is full of contradiction on Cramps... here's a good sample- citing muscle damage, sodium depletion, lack of vitamin D etc., but also showing no real benefit to the most common treatments.
So pick your poison, but ever since I cramped 7 or 8 years ago I've used Saltstick Caps, and not only no cramps for me, but I almost always give some out to someone who IS cramping in those big boudler-field step ups on the long switchbacks before A-Frame.
I want to point out the Caps in question are not interchangeable. Endurolytes have 40grams of Sodium, Saltstick 215, S-Caps 341. You'd have to take 8.5 Endurolytes to get the Sodium in S-Caps, so just be aware they can't all be used the same way.
I personally use Saltstick- Engineered by a Ph.D. chemist who is a Pro Triathlete, they uniquely contain Vit D which the research I link to points out is a leading cause of muscle damage, soreness and slow-
healing injuries in athletes, it aids the bsorption of Calcium. Saltstick also closely mimics what's lost in sweat- Sodium, Potassium, Calcium and Magnesium.
Since I began using them, I've done Ironman, a lot of 100mile Bike Rides in the Mtns, and in Hot-Humid conditions and several more Ascents with no ill effects.
The research doesn't suggest a single source of Cramps, but for me I think the "Pills" work.
Best of Luck!
In response to:
What are your thoughts on using Endurolytes, S-Caps,etc.? I've taken the former on several training runs and longer races, and honestly, I have no idea if they're of any help. Waste of $? Appreciate any comments.