If you're serious about using caffeine as an ergogenic aid rather than an excuse to drink coffee, save its use for before and during actual events.
Nothing fits with cycling so much as the post-ride java stop, and that's probably half the reason many of us get out on group rides to begin with. Caffeine is probably the most common ergogenic aid used in cycling and the world in general, so it's time to take a look at the science behind it.
If there's one thing that fits hand-in-hand with cycling culture, it's coffee and caffeine. Before Gatorade ever came along, diluted and de-fizzed cola was (and often remains) the sports drink of choice, especially near the end of an endurance event. I know my cappuccino machine saved my sanity during the long summer when I was writing up my doctoral dissertation, and it remains heavily abused throughout the year.
First off, the techno-speak. What is caffeine? Caffeine is a chemical in the methylxanthine group of alkaloids. It has a wide range of effects on your body, especially the nervous and cardiovascular systems.
In very general terms, it's a stimulant that prepares your brain and body for "action." As such, some general effects include an increase in heart rate, dilation of blood vessels to ease blood flow throughout the body, and generalized excitation of the central nervous system and its sensitivity to stimulation.
As with any drug though, there are side effects, with the intensity of the side effects generally increasing with dosage. Again, the primary sites for these effects are the nervous and cardiovascular systems, including tremors, impairments in motor control and coordination, anxiety, very high and irregular heart rhythms.
We all know coffee junkies, and caffeine is clearly a drug with a high level of dependency. A standard cup of coffee contains 70-180 mg of caffeine depending on the method of preparation, while tea has much less at 20-35 mg per cup, and cola about 40-60 mg. The effect of any dose depends on many factors, including body mass, built-up tolerance, etc.
Moderate consumption (250 mg) produced strong feelings of elation and peacefulness in subjects, while also improving their performance in several simple mental and motor performance tasks. In contrast, subjects ingesting a high dose (500 mg) experienced more unpleasant effects (anxiety, nausea, heart palpitations) while also impairing their task performance. Name of the game: As always, moderation is key and more isn't necessarily better.
The other side of caffeine dependency is the development of drug tolerance, with a reduction in the stimulant effects of acute caffeine doses in mice receiving steady infusion of caffeine along with motor-sensory and mood depression in the first couple of days after caffeine infusion is stopped. Trained runners also experienced a dampening of the stimulatory effects of acute caffeine ingestion following six weeks of high caffeine ingestion.
So from the above, it's clear that moderation is important. If you're serious about using caffeine as an ergogenic aid rather than an excuse to drink coffee, you need to taper off the regular use of caffeine as much as possible and save its use for before and during actual events. If you still want the post-ride coffee, consider going decaf.
On the Road
Of course, the above science is pointless to discuss if caffeine actually didn't work as an ergogenic aid. The scientific literature is pretty clear that, used correctly, caffeine does indeed help to improve performance on the bike, especially short-term, high-intensity efforts.
Bell and McLellan found that time to exhaustion during a high-intensity effort (80 percent VO2max) was greatly increased following caffeine dosing, and that the benefit was maintained when the same test was performed in the afternoon, suggesting that re-dosing wasn't needed for multi-event competitions.
In contrast to high-intensity exercise, the benefits of caffeine use during prolonged endurance exercise is somewhat less clear. A Scottish study had eight highly-trained cyclists perform 100k-time trial, interspersed with periodic high-intensity 1k- and 4k-efforts, and found no benefit with caffeine ingestion.
Meanwhile, military researchers in Canada found minimal benefits from caffeine ingestion prior to a 10k-run with helmet and backpack. Finally, compared with carbohydrate ingestion, caffeine had no further additive benefit during a 120-minute cycling effort.
Oh yes, one final caveat. As I've pointed out numerous times, no ergogenic aid is going to turn a donkey into a thoroughbred, and supplements are only the finishing touches on top of solid training. Proof? Trained swimmers ingesting caffeine had significant improvements in the swimming velocity, whereas untrained swimmers were found to have absolutely no benefit from caffeine ingestion. So get out riding before you break out the cappuccino maker!