Cyclists have long since had a love affair with caffeine. A ritual, a social lubricant, and one hell of a performance enhancer for many, coffee is the go-to supplement for those seeking a welcome endurance boost. But does it really help us pedal faster? Here’s what you need to know about how much to take, when you need it, and how your genetics determine the effects of a simple cup of joe.

AN ANCIENT RELATIONSHIP

Our relationship with coffee goes right back to the very beginning. Primitive man and coffee bean alike both evolved in the valleys of Eastern Africa, and in the intervening 50,000 years since we left, the coffee bean has followed us to every corner of the world.

A performance enhancer on the bike and an ice-breaker at the coffee stops, coffee provides a welcome boost in times of need to any cyclist. But the story of how we should use this ancient plant ally to enhance our cycling performance is a complicated one. From our genetic predispositions to dosing, and from timing to tolerance, several factors influence how the ancient molecule we call caffeine works its magic in the body of a cyclist.

THE GENETIC FACTOR

For some, one midday coffee is enough to have them staring wide-eyed at the ceiling well into the wee hours. But we all know someone who can consume a double espresso and still fall asleep a half-hour later. Caffeine is a strange compound, and the reason for these wide-ranging effects are primarily down to our genetic makeup.

Just as some are faster on the bike, others are naturally fast metabolisers of caffeine. A variation in the CYP1A2 gene is responsible. Depending on the variant you have, you’re either a fast or a slow metaboliser of caffeine, and it’s this that has a profound effect on how caffeine works in your body.

A 2018 study attempted to quantify the differences in time trial performance with different doses of caffeine across fast and slow caffeine metabolisers. Researchers found that the higher the dose, the faster the cyclists went, but when the results were broken down by genotype rather than dose, the results told a very different story. The fast metabolisers with the so-called “AA genotype” saw a 6.8% improvement in performance at the highest dose. In contrast, the slowest metabolisers, or those with the “CC genotype,” actually saw a decrease in performance of 13.7%. Among these cyclists, coffee actually made them slower.

So, how do you know if you’re a fast or a slow metaboliser? Aside from experimenting, the only sure way to determine whether caffeine helps or hinders your performance is to do a DNA test, many of which can be easily obtained online.

HOW MUCH IS ENOUGH?

Some order a single; while others need a double, but what’s the optimal amount of caffeine for a cyclist?

Researchers in a 2018 study set about trying to answer the question of optimal caffeine dosing for cyclists. In the study, they had willing subjects ride to exhaustion on varying doses of caffeine that ranged between 0, 5, 9, and 13 mg per kg of bodyweight.

As expected, they found significant increases in endurance performance for all caffeine doses compared to placebo. But what was most interesting was that they found no statistically significant differences between the three caffeine dosages, meaning that past a certain dose, more caffeine doesn’t increase performance.

Researchers suggest that a caffeine dose of 3 – 5 mg per kg of body weight is optimal. Given that a typical cup of coffee has 100 mg of caffeine, a 70kg cyclist will likely not receive additional performance increases if they go above two to four cups per day.

TOLERANCE AND THE TOLL OF OVERINDULGENCE

Caffeine consumption is a delicate balancing act. Without it, many of us are cranky and lethargic, while with too much, we’re jittery and wired. For those who respond favourably to caffeine, an additional factor in the equation is tolerance.

Tolerance develops when the body gets too much of a good thing. With repeated caffeine ingestion, the body tones down the sensitivity of the adenosine receptors in the brain. As tolerance increases, so too does caffeine’s usefulness as a performance enhancer. To combat this, some cyclists avoid caffeine entirely unless they have a race or a hard workout planned. Such strategies keep tolerance low while maximising its benefits when it’s eventually consumed. Others prefer to do a short caffeine break in the run-up to a major event, with science suggesting seven days to be the optimal amount of time.

But while the above strategy works for many, don’t underestimate the benefits of regular caffeine use in training. Regardless of a slight bump in tolerance, using caffeine regularly to supplement hard training may be more beneficial than going cold turkey in the run-up to a race. As always, it’s a trade-off, and what works for one may not work for another.

TIMING IS AN ILLUSION

If you’re looking to maximise performance on the bike, then when exactly should you brew a cup of coffee?

Caffeine levels tend to peak in the bloodstream between 30 and 60 minutes after consuming it. While many load up on caffeine before an event, science suggests that consuming caffeine throughout the ride offers the same benefits to performance.

A 2002 study published in the Journal of Applied Physiology set about quantifying how the timing of caffeine ingestion affects endurance performance. In the test, cyclists rode for two hours before completing a time trial under varying dosing protocols. Some cyclists ingested 6mg/kg of caffeine one hour before the test, others ingested 1 mg/kg ever 20 minutes, six times during the test, while others consumed coca-cola before the time trial only.

Results from the tests showed that caffeine improved times substantially, but perhaps the most noteworthy finding was that the timing of caffeine ingestion didn’t make a difference.

SYNERGIES AND AFFINITIES

Caffeine is one of many legal and widely-available compounds that can result in performance benefits. Beetroot juice, sugars, and sodium bicarbonate are three compounds also known to help improve performance, but what happens when we combine them with caffeine? Do they synergise, and is there a ceiling to the potential performance benefits?

Sadly, the effects of combining these compounds aren’t cumulative. Study after study shows that while individually they offer benefits, there’s no way to harness the full benefits of each by combining them with one another.

One study tested the cycling performance of subjects who consumed caffeine and beetroot juice alone, before later repeating the experiment after ingesting both together. While they offered performance benefits when consumed alone, sadly the effects didn’t intensify when taken together. In fact, researchers went so far as to say that caffeine may even negate the cardiorespiratory performance effects of beetroot juice.

Another study carried out a similar experiment but this time with sodium bicarbonate. While the benefits of each when taken alone was clear, there was no benefit when both were stacked. When it comes to carbohydrates — the staple of many cyclists since time immemorial — the results are also surprising. A published study reported that caffeine was still beneficial in terms of performance when consumed with carbohydrates, but was more beneficial when consumed alone. In short, the more carbs you eat, the less effective the pre-ride espresso will be!