Train+ Eat
How coffees can make up for carbs
Why caffeine can replace carbohydrate Do your genes determine the limit of your performance? Our expert knows What to do with those leftover sprouts Our strength circuit for home or gym will make you stronger on the bike
Every cyclist has that one buddy who rides for three hours straight but never seems to eat. So what’s their secret? It might well be that flat white at the cafe.
Caffeine’s positive effect on performance has long been documented, and is variously understood to help access fat as fuel, boost concentration and lower the perception of fatigue. But, as a gathering body of evidence suggests, caffeine also helps make up for times when carbohydrate is depleted, through diet or hard exercise.
Researchers took three groups of cyclists and tested them over a 4km time-trial in a double-blind, crossover, randomised study. The control group had a full rest day before the TT; the other two groups undertook an exercise protocol designed to lower the availability of carbs. The next day, one hour before the TT, the two carb-depleted groups were given either placebo or caffeine intake, at 5mg per kilo of bodyweight (around two strong double espressos).
As a result the placebo group was nine seconds slower than the control group, or 2.1% worse off, whereas the caffeine group was on par with the control. Meanwhile, the anaerobic contribution – that is, energy produced without oxygen, combusted from glycogen stored in muscles and liver – was increased significantly in the caffeine group, whereas the control and placebo groups relied to the same extent on aerobic contributions – energy produced with oxygen, combusted with glucose held in the bloodstream.
This suggests caffeine can restore performance in carbdepleted riders by allowing the body to access anaerobic ‘reserves’ not normally used. So while coffee won’t make you faster, it can prevent you from being slower if you’re under-fuelled during a high-intensity ride.
The terms ‘gene’ and ‘genetics’ are used in everyday language, but because their scientific definitions are so complex it’s easier to explain what genes do than what they are.
Genes relate to what’s passed down from parents to children, including traits such as hair colour, eye colour and risk of disease. We can predict the likelihood of a child’s eye colour from their parents. Eye colour has a genetic code that we can see, and the simplicity of the outcome here is important.
With sports performance the genetic code is less clear because the determining factors are multi-faceted. That’s why researchers have long been trying to identify genes that characterise the world’s best athletes.
There are genetic markers that relate to performance, so following this logic it would be useful if you could know your genetic makeup. But which genes do you seek to identify? Genetic factors aid in the processing and delivery of energy, the production of power and the ability to sustain it – in fact every facet of physical performance. Yet there is still a massive gap in our knowledge. If we tried to list the genetic factors with the potential to affect performance, that might lead us to start making a profile of what the genetically perfect athlete might look like. That’s an extremely complicated model. This process would identify a long list of genes, and then we’d need to work out how many of them are needed and in what combination.
How they interact is complicated and it’s unlikely that any one individual possesses all of the necessary genetic code to reach perfection, simply because of the numbers involved.
The relative contribution of these genes to performance is interactive so it would produce a complex model that would be difficult to understand, and therefore, very difficult to test.
Also, having genetic advantages of fibre type, the availability of energy and lactate threshold might not count for that much if the individual doesn’t have sufficient motivation to achieve the goals when sensations of fatigue
become intense. The decision to slow down in the face of physiological adversity – feeling tired – is not an exact science and some athletes are more motivated than others.
Factors that influence motivation could be genetic, but they are also social and experiential. For example Mexican and Latin American boxers are notorious for their intense fighting style, a feature that’s as likely to be born from the desire to escape poverty as it is genetic markers.
Genetic screening has been extremely useful in identifying diseases, saving lives and improving quality of life. Do we wish to go down a similar line with sporting performance? I’m not sure with the complexity of sports performance that this is achievable with the degree of certainty that would be necessary.
We all have genetic differences and, yes, at some point your genetic code will determine the limits of your performance. But you’re probably not a professional athlete and part of the joy of cycling is training to find out where those limits lie and to push them further. Very few cyclists actually do find out where those limits are and reach a point where they can’t go further or faster for longer.
Genes are important but I think we will always return to more fundamental questions: how athletes maintain motivation, maintain self-confidence, manage emotions and perform under pressure. Those are the limits you should really want to explore.