Posted: 29/01/2015 at 18:30
you definitely should practice this, and assume you won't get it right the first time or two so don't leave it to the last few weeks.
I'm fairly tall and heavy (188cms, 95kgs) and so what is right for me might not be for you.
I use gels only on runs beyond 2 hours, don't need them for shorter than that.
I take one at 40 mins and one every 30 mins after that. SIS Go, 60ml are my preference. Some may say they aren't needed so early and they may be right. If it is too early then no harm.
I also recommend experimenting with electrolytes during your training. Be sure to check what is available at your race so you can simulate in training. Personally I prefer just water and I carry my own electrolyte tablets. I choose Nuun brand. I take 1 at the 1 hours point and 1 at the 2 hour point. for runs of 3 hours or more