Increasing numbers of cross country riders are looking beyond conventional races for alternative ways to test their mettle. This demand has led to an upsurge in the number and diversity of ultra endurance races that are designed to push the competitors to their limits. The Red Bull 24 hours is a recent addition to a long line of extreme races which include: the Alaskan Iditasport race; the Xterra Off road Triathlon; the Leadville 100 mile; and the Moab 24 Hours, to name but a few.

Although ultra-endurance races are physically gruelling, and not necessarily at first appraisal appealing, they do bring with them their own unique rewards. Unlike other forms of racing, where competition is rife and there is an omnipresent emphasis on winning and performing well, the accent in ultra endurance competitions is, for the bulk of entrants, placed firmly on just finishing or surviving the course. With ultras you don’t have to be a hero; it is reward enough just to finish. Anything else is a bonus.

Physiologically, ultra-endurance competitions are within the fitness realm of the majority of well trained mountain bikers if they train accordingly. It goes without saying that physical fitness is a big part of ultra-endurance races, but it is not the whole story. Patience and a dogged perseverance to continue cycling despite being in a deep state of monotonous fatigue can often be the difference between going the distance and pulling out. Training for an ultra is a two pronged approach; you must enhance your resilience and mental toughness while at the same time you must develop your physical fitness.

As the hours go by fatigue sets in. It is not only the muscles that are struggling to work, but also the brain. This is because in ultra endurance races, carbohydrate metabolism often outstrips carbohydrate consumption despite consuming vast quantities of carbohydrate rich foods. As a result, a state of hypoglycaemia is almost inevitable. Our brains will only use glucose as their fuel source, and a significant drop in blood glucose levels is quickly detected. The brain goes into conservation mode, and logically attempts to shut down glucose catabolism by reducing power output. This is known as central fatigue, and it takes a strong mind to override this primal function. It is possible to reduce this impact by training your body to use fat as a fuel and thus, to some extent, spare the blood glucose for the brain.

Before attempting an ultra, your training should be geared towards achieving peak health and fitness. There is no point entering an ultra if you are not in top form as any weakness will undoubtedly be magnified as the race unfolds and may eventually manifest itself as an injury and a DNF. Careful planning and preparation is the key.

You should begin your training as far in advance as possible, anywhere between six and twelve months and split your time into three distinct phases.

Phase one should last anywhere between three and six months. It is here where you should concentrate your efforts on achieving basic health and fitness and establishing a sound endurance base. The second phase of your training, which should last a further three months, focuses on increasing your body’s ability to use fat as the main energy substrate. In order to become an efficient ‘fat burner’ you need to increase the amount of fat mobilising and metabolising enzymes within your body. Fat must be transported to the working muscles, and this takes time. For this reason, you should start your workouts off easy, allowing time for the fats to be mobilised and transported to the muscles. Start off too quickly and you’ll be burning your precious carbohydrates. Slowly build up over a period of 30 minutes to just below your anaerobic threshold and spend at least 30 minutes in this zone. If you don’t know your anaerobic threshold, it is roughly the heart rate at which you would complete a 12 mile time trial. In order to coax your body into ‘burning’ fat you need to consume high quality fat. Animal fats should be avoided at all costs, instead source your fats from fish oils (salmon, mackerel), and vegetable oils (extra virgin olive oil, and flax seed oil). During this phase you should also be training to become a more efficient rider. You must put in some hard rides above your anaerobic threshold in order to improve your aerobic power, and also spend some time working on your riding technique.

In the final phase, which should last 2-3 months you should continue as above, but make your training specific to the event. Most ultras take place in hostile environments, either in the heat, at altitude, or in extremely cold environments. It is during this phase that you should attempt to acclimatise and simulate the conditions as closely as possible in your training.

All of this training and competing takes its toll on your body, and can quickly drain your reserves. The biggest mistake to avoid when competing in ultra endurance races (and it is true for all races) is not to participate in too many. It is an easy trap to fall in to. As you hone your training prior to a competition and feel in top mental and physical shape, coupled with the feeling you get when you finish an ultra, you may be inclined to feel super human and become addicted to clipping more and more of these extreme races. This is a quick fire road to disaster and can facilitate a premature ending to your ultra endurance career. Remember: everything in moderation, especially moderation!

(c) Copyright 1999
John Metcalfe

John Metcalfe is a Mountain Bike physiologist, regular mtb magazine contributor and avid racer. In order to pay the bills he is also a Sports Science Lecturer.