Nutrition for marathon runners

In the first of a two-part series, we look at key areas of focus to enable a marathon runner to excel and remain injury-free.

Kenyan world record holder Eliud Kipchoge recently became the first person to run the distance of 42.4km in under two hours (though it wasn’t ratified by the International Association of Athletics Federations).

The marathon was instituted in commemoration of the fabled run by the Greek soldier Pheidippides from the battlefield of Marathon to Athens to report their victory over the Persians. The marathon was one of the original events at the first modern Olympics in 1896, and Kenyan world record holder Eliud Kipchoge recently became the first person to run the distance of 42.4km in under two hours (though it wasn’t ratified by the International Association of Athletics Federations).

Every year, thousands of people take part in weekend marathons. Running today is more of a lifestyle than a sport. Many of my clients are recreational runners. They average 60-70km per week of running. Some of my runners are elite professional athletes who only train and coach people as part of their responsibility. Many of my recreational runners hold full-time jobs and go through the normal humdrum of life.

Over the last 20 years, I have seen a phenomenal rise in the number of recreational runners. One reason is that people are becoming more aware of the benefits of exercise, and running is one of the best cardiovascular exercises. With many of my clients having high cholesterol, bulging waistlines and doctors asking them to lose 5-10kg, it is but natural for anyone to think they can run their way to better health.

Dr. Ashish Contractor, a close friend who is the director of the department of rehabilitation and sports medicine at the Sir HN Reliance Foundation Hospital in Mumbai, has hundreds of patients with cardiac diseases who he has successfully rehabilitated via running. His recent book Heart Truth is an amazing read for everyone. Dr. Contractor makes everyone run. He runs too! His prescription pad will include a running coach for any of his patients. However, he cautions that marathon running is dangerous for people who have undiagnosed pre-existing cardiac issues.

At our QUA Nutrition Clinics, we do a health gene scan that identifies more than 30 genes that are linked to cardiac disease. The reason for my reading about running and the heart muscle is because I have seen many people injured, damaged or, in the worst case scenario, drop dead because of an unscientific approach to running. In today’s day and age, marathon running is a science. With properly structured training protocols, one can gradually, over 6-12 months, prepare for a marathon. Even heart patients under medical guidance of a sports doctor can run to rehabilitate their health.

 

Thousand of runners take up running without a running coach. Many do a self blood test and then taking their doctor’s advice start to run. In this case, your average doctor may not be the best person to consult, especially if he or she does not have running experience. A sports medicine doctor would be a good bet to start on an assessment discussion. Running can start with a distance of 5, 10, 21, 42km and go up to ultra-marathon distances, which are 60-200km.

The human body can adapt gradually to any sport. Fatigue is an outcome of physical fitness, and this imposes metabolic stresses upon the body. The muscle system is the reason for the demand for glucose in the muscle. Lactic acid is a by-product of glucose metabolism in the muscles, which causes them to experience fatigue. We call it muscle burn. When the glucose reserves are completely depleted, the body relies on safety measures, which will provide for alternative sources of energy. For example, fat is an alternate source of energy, as is protein, which comes from catabolism (breakdown) of your muscle. In the worst case scenario, runners not conditioned will experience a phenomenon called bonking or hitting a wall, where they run out of fuel and collapse. Every runner will face difficult metabolic stresses at different times throughout their training. Some people adapt to these metabolic stresses faster than others. Invariably, those that adapt quickly fall in love with running.

The brain also undergoes a tremendous amount of stress during marathon running. One has to appreciate that glucose is the primary source of energy supporting the human brain, and in the same stride glucose is also the primary source of energy for the muscles. Therefore, there is a constant tug of war between the muscles and the brain towards which requires glucose utilisation more. Elite runners are able to recruit alternative energy systems that sustain them to finish the marathon.

The digestive system of a marathon runner is the least talked about in sports nutrition. I believe that the digestive process slows to a halt when one is running. Human physiology shuts down the digestive system during running as this is a protective mechanism that allows for the conservation of energy, so that the muscles used in running can receive the maximum amount of allocation of energy. However, the sheer impact of running causes physical wear and tear (chaffing) within the walls of the digestive systems. This can lead to microscopic internal bleeding as well as bowel movement due to physical aggression and pressure on the digestive system. In fact, at times runners feel the urge of defecation while running and this is known as runner’s trots. There is a fine line between “eating to run” and “eating on the run.” As a sports nutritionist, I believe hydration with replenishment of certain molecules like glucose and amino acids are key to sustain high-intensity training while being able to bypass the sluggish digestive system.

The other system that takes a huge pounding is the skeletal system, chiefly the tendons, joints, cartilage and ligaments. During each stride, there is a foot strike. The impact on the foot is about two-three times the body weight of the runner. A 70kg runner who has 200 foot strikes per foot per kilometre will endure 30-45 tonnes of force in 1km. Imagine daily training in the run-up to a marathon. The damage is mind-boggling as is the body’s ability to recover.

Typically runners train 60-120km a week and this translates into more than 2,400-7,200 tonnes of force. This astounding amount of stress to the lower extremities increases the likelihood of injuries.

So, as a nutritionist, my key areas of focus to enable a marathon runner to excel and remain injury-free are: 1. Understand the amount of energy the runner expends. 2. Know how much mileage the runner plans to train in the run-up to the marathon. 3. Check for pre-existing heart disease via blood tests, gene tests and heart diagnostics. 4. Look for nutritional deficiencies in the blood and ramp up. 5. Plant an exercise wearable that tracks steps and heart rate. 6. Understand sweat loss rates in a runner per marathon.

 

In my next article, we will target the calories designed over breakfast, lunch and dinner along with the pre- and post-run strategies for food consumption. We will also explore how nutritional deficiencies can be tackled by foods and supplements. Finally, we will look at supplements that help build longevity in the ligament and cartilages of runners.

The author is the sports nutritionist to Nitendra Singh Rawat, an Olympic marathon runner who holds the Indian record for the fastest time at the Mumbai Marathon, and can be reached at ryan@quanutrition.com for a runner’s diet.