Caffeine timing during races (specifically marathon)

nusaka wrote:

It seems most of the science points to a 60 minute absorption to reach max levels of caffeine, however, in my experience of taking caffeine gels (Maurten 100g) before a race, followed by a second one 60 minutes in... I both felt a crazy caffeine high not long after the second one and caffeine crash later on... (around mile 17/18). It seems to me at least that the adrenaline and buzz of the race would have been more than enough to sustain me for at least the first hour, possibly hour and a half, and I only really needed the burst of energy towards the end of the race. I personally seem to feel the effects of taking caffeine during exercise almost immediately and not only do they not appear to reach peak levels after an hour, I actually feel a caffeine crash after an hour... so I am just curious to know other's experience with this. Perhaps it depends on the effort level?
For context this was during the Boston marathon and my heart rate was an average of 174, max of 184 according to Garmin wrist sensor. I finished in 2:54, about 6:25-6:30 mm in the earlier half and closer to 6:40-6:45 mm second half. It was very very hot towards the end, pushing 70 degrees F and very exposed, so think the heat was definitely a factor as well, although I stopped at nearly every aid station, switching between Gatorade and water. Also had a total of 6 gels (+1 before race) - 2 of which were caffeine.

nusaka wrote:

It seems most of the science points to a 60 minute absorption to reach max levels of caffeine, however, in my experience of taking caffeine gels (Maurten 100g) before a race, followed by a second one 60 minutes in... I both felt a crazy caffeine high not long after the second one and caffeine crash later on... (around mile 17/18). It seems to me at least that the adrenaline and buzz of the race would have been more than enough to sustain me for at least the first hour, possibly hour and a half, and I only really needed the burst of energy towards the end of the race. I personally seem to feel the effects of taking caffeine during exercise almost immediately and not only do they not appear to reach peak levels after an hour, I actually feel a caffeine crash after an hour... so I am just curious to know other's experience with this. Perhaps it depends on the effort level?
For context this was during the Boston marathon and my heart rate was an average of 174, max of 184 according to Garmin wrist sensor. I finished in 2:54, about 6:25-6:30 mm in the earlier half and closer to 6:40-6:45 mm second half. It was very very hot towards the end, pushing 70 degrees F and very exposed, so think the heat was definitely a factor as well, although I stopped at nearly every aid station, switching between Gatorade and water. Also had a total of 6 gels (+1 before race) - 2 of which were caffeine.

Cafe. wrote:

This will end up being a very personal and subjective answer and strategy for each person.

Be careful not to conflate the effects of several overlapping variables in your decision making:

1. Technically the half life in the grand scheme of caffeine digestion means if you take it right at the start it will still be in your system at the end of the marathon. So taking more, means you're opening yourself up to however your body reacts when you take a lot of caffeine without clearing it.

2. The beautiful feeling 30-60 minutes after consumption means different things at different effort and fatigue levels. Trying to blast an all out 5k while utilizing the suffer-numbing effects means you get to stop all exercise and exertion 15-20 minutes later and allow your digestive processes to function properly. if you take those 400mg of caffeine 2.5 hours into a marathon, your digestive system is in near shutdown, you are already feeling terrible effects of rhabdomyalysis, and you now have to continue exercising.

3. Caffeine has in more recent research been shown not to be the greatest contributor to allowing the human body to offload heat during exercise in sun/heat. this again may end up being a person to person difference, but in sunny warm marathons you could argue the effect of caffeine becomes detrimental when your body needs multiple hours of skin and core body temperature regulation more than the caffeine effect. I would argue this comes as a double dose of suffering to people that train in cool winter/spring weather then step out into a warm sunny spring marathon and have no acclimation/acclimatization to start, and then have to effect of further dulling their ability to tolerate heat/sunlight with caffeine. The same studies showed a slightly better heat tolerance with Taurine, but I don't know if the science is there to back up that being a positive thing.

4. The length of the marathon and perceived effort combined with muscle soreness probably negates the minimal effect of caffeine late in the event. There's a reason pro peleton cyclists were using higher test illegal painkiller type stuff in their late stage finishing bottles, because to feel good under fatigue is harder than feeling good in the first hour.