Hi @smariej .  I'm not an REI employee, and it seems they've already nailed the advice on keeping hydrated.  I never used to use a bladder, but once I tried, I've become a convert.  I put my water in the bladder, and carry a bottle with a sports drink in a side pocket.  I also, like @REI-HeatherK , eat a banana before a hike (and sometimes an oatmeal bar too).

I wanted to address your comment about the group moving too fast to allow you to take a break.  I think it's important that you communicate your needs and limitations to the group.  Most all hikers and groups I've encountered are friendly and helpful people and will make the necessary adjustments to best suit everyone in the group.  If they are not willing to do that, perhaps you should find a new group to hike with.

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