Preparing for nutritional challenges on expedition

In the previous post, we noted that ‘nutrition can have a massive impact on both your training success, and on your ability to adjust to prolonged exposure and altitude.’

One of the major challenges on any expedition is preparing yourself from a nutritional perspective. This is a double-edged sword, as inappropriate nutrition can scupper your efforts well before you even get close to completing your preparations.

A well-balanced diet is essential for stimulating and enhancing adaptation from training. An appropriate mix of the macronutrients (carbohydrates, fats and protein) along with important micronutrients (vitamins and minerals) are all required to ensure that you build tissues, change your internal chemistry and recover from regular exercise. The foods you consume are also essential during your daily workload to allow for a level of physical performance required to cover the required distance and recover/regenerate for the next effort – this also helps the body to limit tissue damage under severe climatic conditions and altitude.

Your body will return from an expedition with reserves of energy (and some of the working parts) significantly depleted. Many climbers return from expeditions with noticeable losses in total mass, reduced body fat and wasted muscle. Remember you will have to rebuild all of this, and get back to peak physical condition before attempting your next hurdle.

Unfortunately, expeditions take place in environments where high-quality foods, along with their storage, transport and preparation are just not possible. You and your body will need to learn how to live out of tins! The majority of foods realistically available on the sides of a mountain are limited to various forms of sealed packaging. In addition, proteins are difficult to provide and the majority of climbers (especially due to fatigue and altitude) cannot stomach heavy, protein- and fat-rich meals (never mind carry them up there!). In addition, the balance of the macronutrients and essential micronutrients are often not at a level that can sustain sustained performance or limit tissue damage. Carbohydrate-based items are by far the easiest to prepare and consume – however, carbs only provide short-term energy, and can do little to spare your muscle from wasting.

The body requires energy, resources and oxygen to complete digestion – under the adverse conditions experienced during expeditions, your body (and especially the liver) just doesn’t have the energy to digest and reduce food items into viable energy.

In short, your body slowly (or sometimes quickly) starves itself – reduced performance and restricted work capacity quickly follow. This is one of the reasons why short acclimatization stages are effective – you climb to a higher altitude, and return to a lower altitude after a relatively short period, so the body can recharge – this happens not only due to the body’s inability to operate under reduced oxygen pressure, but also due to the restricted ability of the body to function continuously under high stress without adequate fuel – go back down to recharge the batteries!

You don’t need to climb a mountain to climb a mountain!

The trick is to balance getting used to eating the types of foods you’ll get on your trip (and to be comfortable with the type of preparation), with the high-quality foods that encourage maximal adaptation from your training and preparation.

In short, practice with ‘expedition food’ periodically, but make sure you generally eat well to build your body up for the challenge during your routine training. You also need to pay attention to how you respond to any food allergies or intolerances, and how these may affect you body under the combined stress of exercise, fatigue, adverse weather conditions and increasing altitude.

Zac van Heerden

M.Sc (Med) (Exercise Physiology)