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Mountain biking is one of the fastest growing sports in Australia. With the many disciplines available, there is something for everyone. Whether you love the challenge of a long, steep climb or you are more into fast and technical terrain, the demands on the body are high and understanding this will help you train and fuel optimally.

It is no secret that cross country mountain biking (XCO) is raced at a high intensity, with a heart rate averaging around 90% and more than 80% of the race spent above lactate threshold. The long climbs require a high power output of up to 500W.

As a consequence a cross country rider will need to be able to sustain high work intensity for prolonged periods of time and optimising anaerobic energy metabolism is key. Differently to many other races, the sprint in XCO is at the start of the race, requiring high energy availability from the start, making pre-exercise nutritional strategies a key factor.

Many people think that enduro racing on the other hand is not as demanding as the climbs are not timed. The research paints a different picture. Although the climbs are not timed, the best riders overall tend to place the fastest times on the climbs as well as the technical sections.

The demands are very similar to those of XCO: large aerobic capacity, high power at sub-maximal workloads and high peak power output. Just as the physiological demands of enduro are similar to XCO, so are the energy demands.  

Surely, downhill is a different story right? I mean, they don’t even ride up the hill, they get shuttled, they are definitely not going to need as much fuel, or are they?

Research into the physiological demands of downhill mountain biking show that riders select intensity level based on overall fitness, skill, efficiency, terrain condition and comfort levels. More experienced and skilled riders, who are also more willing or able to accept the risk, have shown to select higher intensity levels.

Downhill mountain biking has been described in the literature as a vigorous full body exercise, with aerobic-anaerobic engagement of a large muscle mass including not only the legs but the core and arms too. It has been found to be similar to off road motorbike riding, with the standing on pedals/pegs, with the aid of large front and rear suspension, navigating through narrow uneven terrain, posing similar demands on the body.

The hand grip, core stabilisation and standing position means that the activity is perceived as harder than the metabolic demands indicate. Peak power output and time to peak power combined with speed during the technical section are key to performance. Although a downhill run is of short duration, riders typically will do multiple runs, which increases their energy demands. It is particularly important to consider the impact that energy intake has on brain function, especially when considering a rider’s ability to control their bicycle may be compromised after sustained riding. Strategic fuelling can support brain function and ability to control the bike and select the most appropriate line.

I apologise for some of the technical jargon, what it really means is that although the disciplines are different, they all place large demands on the body. Whether the climbs are time or not, riders still have to execute them; and even if you are not climbing yourself, the larger demands of the technical terrain on the downhill runs create just as high demands on the body.

Fuelling your riding is key for performance, bike handling, line choice and overall enjoyment. Fuelling adequately before, during and after a ride means more fun, better riding and recovery to be ready to do it all again tomorrow. The demands are high no matter the discipline, when and what to eat though will be different, that’s where a specialist dietitian can unlock the secret to fuelling for performance in your discipline.


Hadden, S. Physiological contributions to successful downhill mountain bike performance. 2011.

Burr, J et al. Physiological demands of downhill mountain biking. Journal of Sports Sciences 2012.

Kirkwood, L. Performance in enduro mountain biking: the influence of training status, recovery and vibration. 2019.

Impellizzeri, F et al. The physiology of mountain biking. Sports Medicine 2007.

Bejder, J et al. Physiological determinants of elite mountain bike cross-country Olympic performance. Journal of Sports Science 2018.

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Marzia Bell

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