I have been experimenting with using caffeine to help with the RPE of races. From the podcasts, I learned that normal impact is about 20 minutes after taking it. So I have been taking it as close to the start of the swim as possible (1 pill). That has it kick in just as I am coming out of the water. Though I can often feel it hit about half-way through the swim.
In one of the recent ThatTriathlonShow Podcasts, @Mikael_Eriksson stated to take it 60 minutes before the race.
Total race time for me is normally 2.5 to 3 hours. So 1 dose only for me. Outside of racing, I do minor amounts (about 1.5 cups of coffee per day), so the sensitivity is there.
When do you take caffeine and why?