Getting fluids on long training rides/runs

For the runs, just a Fuel Belt.  If it's really hot, and the run is approaching 3 hours, plan on either multiple loops to refill at your starting point, or stopping at a convenience store.

For biking, 2 frame cages, and a third bottle in a torpedo mount between the bars.  Again, this is enough for about 3 hours, so plan on either multiple loops or convenience stores to refill.  If loops or stops aren't an option, then adding two more bottles in a behind the saddle mount increases your capacity to 5 bottles.  For most people, this will carry you through 3-6 hour rides, depending on the temperature and individual fluid needs.

I use a handheld bottle for long runs of an hour and up when its hot (I live in FL) I do loops back to my house and leave a cooler with bottles in my front yard.  For long bikes also do loops.  I can carry about 80oz with me on my bike and then loop back to my care to re-load.  Most of the trails I ride usually have places to stop for water so I could refill. I have also stopped at convience stores. 

Thanks for the replies everyone!  

So it seems that the most common practice is to have a plan to replenish along the way (via loops or planned stops) rather than go overboard on increasing your carrying capacity to avoid refills.  But probably carry more than what you would on race day since refills will be less frequent.

I had been using a fuel belt for my long runs but got a Nathan hydration pak this summer and I much prefer it.  On a long run/ride I am glad to have it for the extra fluids and pockets for food, cell phone, etc.