Carbohydrate – Runner’s friend or foe?

2016-03-19 13.52.22
Should we ditch the humble potato?

Growing up in the 1990’s watching my Dad carbo load days before each of his 10 marathons and attending pasta parties thrown by the organisers the night before the event I have always understood that traditional carbs (pasta, rice, potatoes, doughnuts etc) are essential to any long distance training and racing. Dad’s friend who was training for 100 mile races (ultramarathons) regularly had to get up in the middle of the night and eat a bowl full of have pasta simply to have enough energy for the next day. This carb heavy world was driven by US government guidelines and advocated by Sports Scientist Tim Noakes in runners’ bible ‘The Lore of Running’. In recent years though there has been a backlash against traditional carbs. Noakes himself, based on further research both personally and in the lab, has renegaded on the carbo loading mantra[1]. So where does this leave us on whether we should be eating carbs or not?

The Low Carbohydrate, High Fat diet, (LCHF) has been advocated by many ultra-runners and Dr Phil Maffatone[2] to improve performance.  The premise of this diet is that as a fuel fat is in more abundant supply than carbohydrate/ glycogen, hence a better alternative for long distance events such as the marathon. For example as a 10 stone person you may have 80,000kcals stored in fat[3]. So if the body can be trained to burn fat or become ‘fat adapted’ then it has a greater fuel supply than carbs/glycogen which typically lasts for 90mins. What LCHF means is no bread, no pasta (not even wholegrain), no potatoes, no grains and very little fruit as it is full of sugary carbs. Fats are encouraged, both the healthy kind (nuts, avocado) and saturated fats (dairy and meat). 50-70% of calories come from fat, where in a conventional runner’s diet this would be 25-30%[4].  Similarities have been drawn to the Atkins and paleo diets which have been shown to assist in weight loss and do have some advantages for health. The LCHF diet has been criticised by nutritionists for the reduction in fruit that it advocates, given the positive benefits fruit can bring – antioxidant, anti-inflammatory and micronutrients.

Scott Jurek – ultramarathon champion (6 time winner of the Western States 100 Mile Endurance Run) and author of Eat and Run argues that a plant based/ vegan diet – carbohydrate rich (60%) and low in fat – has revolutionised his endurance event performances. In Jurek’s vegan world carbohydrates are only low GI whole foods – sweet potatoes, whole grain rice, sprouted greens and fruit. The sugar in fruit he argues is not bad when eaten with the naturally occurring fibre. Protein is legumes, nuts, seeds and pulses. No refined carbs which can lead to a host of health problems (type 2 diabetes, heart disease, obesity).

Plant based foods are rich in fibre, vitamins and minerals, supporting everything from digestion to cell growth and your immune system. A study at the University of Stellenbosch[5] revealed that antioxidant supplementation, (vitamins C, E and beta carotene) can support immune function following exercise, suggesting vitamin-rich fruit and vegetables are important for runners[6]. As a vegan athlete Jurek feels that his diet has given his body the nutrition to take on the stress and load of training and racing[7].

Cutting out meat has health and wider ethical implications. By eliminating red or processed meat, your risk of developing various conditions, such as heart disease, type 2 diabetes and cancer[8]. More creativity in the kitchen may be needed if you have traditionally eaten meat as the centre of your meals, but those who have made the switch have enjoyed discovering new ingredients and tastes.

Vegan’s will miss out on the benefits of dairy and fish to aid recovery. Milk which if drunk after training is a superior source of protein and carbohydrate, stimulating muscle repair and regeneration when compared to sports drinks[9].  Whilst oily fish can help to reduce inflammation.

Whilst both diet approaches for distance runners – LCHF and vegan – may be extreme, what works for me has been a number of elements in both approaches.  LCHF yes to eating more healthy fats and rule out traditional refined carbs which can be done in favour of low GI and wholegrain as per a vegan diet.

As a non-distance runner (less than half marathon/ 10km) you may be asking what does this mean for me? If you are running for less than 90 mins you are still operating within carb/ glycogen fuel stores. Research on carbohydrate which produces glycogen is clear –  glycogen is by far the superior fuel for short, fast efforts. If you ask the muscles to fire quickly the power will be dramatically reduced if your glycogen stores are depleted[10]. So for performance there is little benefit in ditching the carbs and training the body to fat adapt, however if you are trying to lose weight for health purposes (and perhaps to improve your running) a level of fat adaptation would be advantageous.

For me right now as a middle distance runner a balanced and nutritious diet sums up my approach. Some of the rules I try to live by are;

  • Protein (meat when I am confident of the source) should be eaten within an hour of training for tendon growth and repair.
  • At least 2 portions of oily fish per week for repair.
  • Eat low GI (wholegrains, brown rice, bread and pasta) as opposed to refined alternatives – not only for performance but also for general health.
  • Raw food – nutritionists advocate that some should be eaten at every meal. A nutri-bullet though is a more convenient and practical solution to salad for breakfast!
  • Good fats – eat nuts and seeds as a snack as opposed to carbs and refined sugar.
  • Turmeric and ginger boost immunity in order to ensure you don’t miss training due to illness.
  • Not eating large meals after 6pm which can impact on your sleep (vital recovery time).
  • 4/5 smaller meals as opposed to 2/3 larger ones throughout the day.
  • Eat carbohydrate three hours before a race to maximise available fuel.
  • Run before breakfast to improve muscle adaptation to endurance[11].
[3] Seebohar, Metabolic Efficiency Training, 2009
[4] Runners World, March 2016 issue
[7] Eat and Run, Scott Jurek, 2012
[10] Runners World, March 2016 issue
[11] The BBC Food Programme,