I recently ran my first half-marathon and was having trouble during my long-run training with quad cramping. I tried various products without much improvement. I came across e-Gels late in training and only got to try them once before the race, but during the race (and since) they worked great. I took them 45 minutes in (5 miles) just as i started to feel the cramping, and immediately felt relief. Took a second at 97 minutes (11 miles-lesson learned: find out where water stops are before the race) when my legs were really tight; took a little bit but they once again relaxed and i was able to pick back up to my normal pace. They’ve worked consistently on my long runs since then too. I have recommended them to several friends (even gave away some packets) and they worked for them too. Great product-glad i found them.