I'm a big fan of caffeine. A caf-fiend, some might say. It is rumored that ethiopian shepherds first noticed the effects of caffeine after observing energetic behavior in their goats who had just eaten coffee.
Athletes are looking for that same energy.
Two recent studies on caffeine are worth mentioning. In the first, a caffeine related improvement in performance was seen, but not in everyone. Although 7 out of 9 individuals had improved performance, the overall improvement in performance was 1.6-1.9%.
The dose of caffeine used was 5mg/kg, taken 90 minutes before exercise. Caffeine doses between 3 and 6 mg/kg have also shown improvement in performance.
The same authors also found that caffeine, caused an improvement in cycling performance in trained individuals, which might help explain why only 7 of 9 individuals did better.
Caffeine increases heart rate and decreases mood, two side effects that you might not want.
Caffeine works by increasing adrenaline which, in turn increases circulating fatty acids that can be used as fuel. If you are using predominately slow twitch fibers, then you will have more of an effect from the caffeine than if you are using predominately fast twitch fibers. Of course, everyone has a different muscle fiber profile, so if you don't know yours, then it will be hard to determine if caffeine ingestion will work for you.
Some other interesting caffeine facts:
- Eating green leafy vegetables will lessen breakdown and clearance of caffeine , giving an extra kick (Kale latte, anyone?)
- Taking Zantac (cimetidine) will also keep the caffeine from being broken down
- You don't need to withdraw from caffeine to have it make a difference
- Repeated small doses of caffeine (1-2g/kg) during prolonged exercise can also help
Astorino TA, Cottrell T, Lozano AT, Aburto-Pratt K, Duhon J. Effect of caffeine on RPE and perceptions of pain, arousal, and pleasure/displeasure during a cycling time trial in endurance trained and active men. Physiol Behav. 2012 May 15;106(2):211-7. Epub 2012 Feb 12.
Astorino TA, Cottrell T, Lozano AT, Aburto-Pratt K, Duhon J. Increases in cycling performance in response to caffeine ingestion are repeatable. Nutr Res. 2012 Feb;32(2):78-84.
Graham TE. Caffeine and Exercise; Metabolism, Endurance and Performance. Sports Med. 2001. 31(11); 785-807