I’m training for a marathon – how can I prepare my body

Whilst exercise and training have multiple benefits to health including: improved muscle mass and function, cardiovascular function, blood sugar regulation and respiratory health; excessive amounts of training are associated with an increase in oxidative stress, high cortisol and inflammatory markers. As such, it is important to consider the impact of long-term, high intensity training on overall wellness – to perform at peak, reduce the risk of injury as well as ensuring the best recovery.

The best nutrition for endurance training

Macronutrients

Carbohydrates

Carbohydrates provide the main source of energy in endurance exercise. Stored glycogen in the muscles and blood glucose, both maintained through adequate carbohydrate consumption, provide the main fuel for muscle contraction, and a deficiency can result in reduced performance and being quicker to fatigue.

In order to maintain adequate energy stores, it is recommended that marathon runners ensure they consume 1-4g of carbohydrates per kg body weight between 1-4 hours before the race.

Opt for gluten free wholegrains such as brown rice, quinoa and sweet potato, fruit and vegetables, whole oats, beans, and pulses – which will provide carbohydrates along with other phytonutrients, and avoid refined carbohydrates (white bread, pasta, pastries etc.).

Protein

Consuming adequate protein is essential for building and repairing the muscle tissue that will become damaged during marathon training – and will maximise recovery and training adaptation.

Exercise breaks down muscle proteins, so marathon runners require a higher protein intake than the average person just to prevent the loss of muscle tissue and consequent reduction in muscle strength.

The consensus among sports nutritionists is that endurance athletes should consume 1.4-2g/kg/day of protein. Great sources of protein include meat, fish, eggs, dairy, pulses, grains, nuts, and seeds.

Vegan and vegetarian athletes should be mindful to include a variety of protein sources in order to obtain the full complement of amino acids – and a protein powder supplement may be helpful.

Fats

To maintain health while training for a marathon your diet should contain adequate fats, as fatty acids form part of the cell membrane, are essential for brain and nervous system function and are needed to absorb and transport the fat-soluble vitamins, A, D, E and K, which play a role in energy production.

You should ensure an adequate intake of Omega 3 fatty acids, found in oily fish, some seeds such as flax and chia, and in supplements – as they have been shown to improve reaction time, muscle recovery, reduce inflammatory markers and improve cardiovascular dynamics.

Micronutrients: Vitamins and minerals

As a marathon runner, it is important that you provide your body with the nutrients it needs to optimise metabolic function, as any deficiencies could result in the body prioritising short term survival, at the detriment of enhancing long term health and performance.

For example, the B Vitamins are needed to support the mitochondria and energy production, magnesium is needed for muscle function and iron, folate, and vitamin B12 are all fundamental elements for red blood cells and thus essential for delivering oxygen around the body – so any deficiency could result in decreased exercise performance.

A comprehensive, appropriately formulated multivitamin and mineral is advised to cover any nutritional shortfalls.

Exercise, free radicals and the importance of antioxidants 

Strenuous exercise can also create increased production of free radicals, which can overwhelm the body’s natural antioxidant system, resulting in oxidative stress, which can affect performance.

Supplementing with antioxidants such as N-Acetyl cysteine, vitamins A, E and C, glutathione, ubiquinone (Coenzyme Q10), and flavonoids can be supportive, as well as ensuring an antioxidant rich diet through brightly coloured fruit and vegetables – “eat a rainbow”!

Rest and recovery

Finally, rest is an essential part of the recovery process, and critical to improve training capacity and, ultimately, performance. During rest, the body can adapt to the stress of exercise, replenish stored glycogen, and has time for the muscles and other tissue to repair.

Sleep is especially important in endurance sport, and those who are sleep deprived may experience changes to hormone levels, with increased catabolic and reduced anabolic hormones resulting in impaired muscle protein synthesis and impeded recovery.

Nutrients such as 5-HTP, magnesium, vitamin B6, glycine and L-Theanine can support restful sleep.