Endurance Running – A Marathon Effort

The lure of the marathon (half or full) attracts many a runner.  Not only does it test physical endurance but it is a measure of mental determination.

The motivation to complete a marathon is as varied as there are runners. For some, it is an opportunity to achieve a personal best, others aim to merely complete it.

It can also be an occasion to run in someone’s honour.

While we cannot all be Olympic athletes, marathons enable us to unleash our own olympian efforts and show what we are made of.  

Those who participate in a marathon are not the same person they were when they lined up.  All marathon runners rightly earn their sense of achievement – a check on their “bucket list”.

“I've learned that finishing a marathon isn't just an athletic achievement. It's a state of mind; a state of mind that says anything is possible.”  John Hanc

Of equal consideration are the effects of the marathon on the runners’ body. Physiological changes are profound as you willingly pound that pavement.

This does not mean that marathons are necessarily harmful, however it does require the combination of appropriate training, an adequate diet and supplemental assistance.

So before you channel your inner Kenyan, read on to ensure that your relationship with marathon running is a healthy one.

Physiological effects of a marathon

Despite the odd dismissive remark that running damages joints and heart health, marathon runners are deemed to be healthier than the general population. Here are the effects of chalking up those miles:


The average marathon runner will land with full weight on each foot between 13,000 – 20,000 times. Not surprisingly, the onset of blisters and the tell-tale “runner’s toe”- a blackened nail can be commonplace.

By choosing suitable socks and footwear, these minor complaints can be avoided.

Of greater concern are the common injuries of the foot. Plantar fasciitis, Achilles tendonitis and Posterior tibial tendinitis are the most cited running injuries. All are the result of inflammation or tearing to the affected area by overuse of the ligament and tendon.

The main way to prevent such injuries is by using the correct shoe and training appropriately.


The tools of trade for the marathon – the legs – are understandably under pressure to perform. With correct training, leg pain and injury can be minimised however there is the potential for injury.

Runners can fall victim to shin splints, ankle strain, iliotibial band syndrome and patellofemoral pain (pain felt behind the knee).


Moving the body along the marathon course requires the alternating contraction and relaxation of muscles. The fuel to enable this muscle activity is Glycogen (our stored carbohydrate).

Our bodies (even those very fit athletic physiques) are only able to store enough glycogen to enable 60-90 minutes of strenuous exercise.

This highlights the importance of fueling during the event to avoid “hitting the wall”


Obviously much is required from the heart during a marathon event. Its job of circulating blood throughout the body is made more difficult by the rise in stress and the potential drop in fluid from sweating.

Nevertheless, marathon running is good for your heart health and this temporary stress has been shown through numerous studies to have no long-term detrimental effects.

Those cases of sudden deaths occurring at marathons are usually the result of an undiagnosed heart condition. It is important therefore for anyone considering running a marathon to have a thorough physical examination.


The increased lung capacity attributed to marathon running is largely due to changes in the muscle cells. This allows them to become more efficient and move blood through the lungs faster.


As the marathon runner lines up for the race, the brain is on alert and shifts into “fight or flight” mode. This results in blood flow being diverted from the digestive tract to the muscles.

Furthermore, the concept of a “runner’s high” has been recognised by leading endorphin researchers. The release of brain chemicals – endorphins – change an athlete’s mood.

These naturally occurring opiates boost that “feel good” feeling after an intense run.


Generally, a male’s body is 60-65% water and a female is 50-60% water. Most of this water is stored inside the cells particularly the muscles.

Consistently perspiring can result in the loss of just under a litre of water and 30mls of salts and electrolytes per hour.

If this is not replenished, the body will shut down.

Be aware of the condition hyponatraemia – this is when the runner overcompensates for dehydration by drinking an excess of water minus the essential electrolytes / salts. Blood sodium is dangerously diluted and the kidneys become “drowned” in water.

The inability to effectively excrete the excess water can result in symptoms of headache, confusion, seizures, restlessness, muscle spasms and general weakness.


Emed Comment

There is no doubt that you earn your running stripes when participating in marathon events. No longer a “jogger”, a marathon runner is a badge to wear proudly.

To get the most from your marathon event, consider the role of training, diet and relevant supplements.

A “real food” diet is the foundation for your athletic performance. Eating a balance of protein, complex carbohydrates and essential fats will enable you to be physically ready and mentally prepared to train.

Rather than snacking on a menu of ingredients, opt for lean, healthy and fresh foods. There is no magic pre-event dinner or breakfast. Stick with the familiar foods that have seen you through your training. Emed's article Health Promoting Nutrition can assist here.

The esteem of a marathon comes from its physical commitment. No amount of carbohydrate loading, powerade drinking or protein bar snacking will enable you to complete a marathon if you haven’t done the hard yards beforehand.

Getting kilometres on those legs is paramount if you want to run a marathon safely and well.

No Magic Bullet

While a completely different sport, competitive cycling highlights a sad sporting phenomenon, namely the desire to perform better at all costs.

Nearly every Tour de France since the late 1980’s has been plagued with scandals of doping to improve performance.

These athletes risk not only disqualification from the sport but also severe health concerns by willingly using human growth hormone, steroids, stimulants, amphetamines and diuretics to get an edge on the competition.

On a much smaller scale and without the risk of shame and health concerns, the average marathon runner can be lured by the promise of certain supplements to boost their running performance.

Sorting out nutritional fact from fiction can be overwhelming. Key nutrients to consider as part of your training program are found in the article Run Forrest Run.

Listed below are supplements aimed at endurance runners.

Energy Drinks, Bars and Gels

As mentioned, the body loses a significant amount of fluid and only contains enough stored carbohydrate to fuel about an hour’s worth of exercise. This is where energy drinks, gels and bars can be your friend.

A decent sports drink can provide the triple benefit of providing fluid, electrolytes and carbohydrate. By adequately fueling throughout the event, your heart will beat efficiently, your body temperature remains stable and dehydration is avoided.

Energy bars and gels provide you with much needed carbohydrate that fuels your muscles during the event. When running longer than 90 – 120 minutes, aim to eat approximately 30-60g of a carbohydrate per hour of exercise.

These can also be used to replenish glycogen stores afer the event also.

Experiment with gels as they can induce stomach upset and cramping. They are best taken with approximately 120 – 180mls of water (not sports drinks)

Research has also shown that by drinking sports drinks in events longer than 90 – 120 minutes the immune system has efficient fuel to cope with the stress of prolonged exercise.


Recently heralded as the nutrient to boost athletic performance, Carnitine (or its derivative Acetyl L-Carnitine) transfers fatty acids across the cell membranes of the mitochondria so that it can be used as a source of energy.

Consequently it is regarded as a great way to promote fat loss while boosting performance.

While still being researched, initial findings are indicating that it may have a role in increasing stamina. For sporting results, you need to aim for 1-4 grams per day.

Dr Vera's Acetyl-L-Carnitine and Mitochondrial Energy Maintenance are both great Carnitine supplements available from Emed.


This amino acid is the most abundant in the body and is important for digestive and immune health. Glutamine reserves are depleted in times of stress such as infection, trauma and even exercise.

In fact, running a marathon can depress blood levels of glutamine and several hours of recovery are required to restore levels.

Low glutamine levels have been measured in athletes suffering from overtraining syndrome.

Consequently, supplementation can assist in maintaining muscle mass, decrease muscle damage and shortening recovery time. Furthermore, the immune system is strengthened.

Emeds Best Glutamine Supplements:

Branched Chain Amino Acids (BCAA’s)

The BCAA’s – leucine, isoleucine and valine – are located primarily in the muscle and are often broken down and burned for energy during exercise over two hours as glycogen levels fall.

Supplementing with BCAA’s can technically improve performance by preventing muscle breakdown and damage. Mental fatigue associated with prolonged exercise can also be delayed.

While promising in its research findings, the jury is still out on BCAA’s as a performance enhancing supplement.

Emeds Best BCAA's: