FITNESS Hitting a wall in a race

Hitting a wall in a race


How to the get to the finish line without breaking down from fatigue

Personal trainer
Paul O'Brien

Everyone seems to be out on the road these days. There has been an explosion of interest in adventure racing, triathlons and endurance events. Many are taking to these sports for the first time and encountering the challenges for the first time also.
One of the inherent challenges with endurance events is getting to the finish line without breaking down. In marathon running, this breakdown has traditionally been known as ‘hitting the wall’. It’s that point in a race at which your body simply gives up – your muscles begin to cramp, you slow significantly and may even have to stop altogether. I remember hitting the wall in the London marathon in 1999, losing control of some bodily processes at the same time!
Should you be accounting for this eventuality in your own training? If the events you are partaking in last for over one hour, then you should have a strategy to avoid hitting the wall. Therefore, anyone training for half-marathons, marathons, adventure races or sprint and Olympic distance triathlons should probably take note. The longer your event, the greater the importance of catering for this aspect in your training.

Breaking through
When you hit the wall, your body is overpowered by fatigue. Your body fatigues when the muscles are clogged with waste products and cannot function properly. Lactic acid is a by-product of carbohydrate breakdown in your cells. As the intensity of exercise increases, so too does the accumulation of lactic acid. When the accumulation outstrips the muscles’ ability to remove the waste, the muscles stop working. However, because most endurance events occur at low- to moderate-intensity levels, the body can usually keep pace with the lactic acid production and remove it before it can cause you any problems.
A muscle can also simply stop contracting (working) in an effort to protect itself from injury. When a muscle is subjected to a repeated stress, the brain may signal the muscle to stop contracting. This is a defence mechanism employed by the brain. To override it, you should include a high-intensity session in your training once every seven to ten days. A hard hill session or running 400s on the track are good examples.
By far the most common cause of fatigue during endurance racing is a lack of an adequate fuel supply. For beginners, training and competing at very low intensities, this may not pose too many problems as your major fuel source at low intensity is cellular fat, of which the body has an adequate supply to get you through. However, as you begin to improve or for those competing at higher intensity, the critical fuel source becomes carbohydrate. The body stores far less of this source, in the form of glycogen. Once it runs out, you will slow dramatically and may even stop. The key strategies to help conserve this vital fuel source are twofold – diet and training.
Ensuring you are consuming enough simple and complex carbohydrates in your daily diet is critical to replenishing stores of cellular glycogen. Your strategy should also include topping up on carbohydrates in the days before an event. Meal timing and content become more important the further you progress. Without a dietary strategy, you can only progress to a certain point.
To train your muscles to conserve glycogen, you should perform at least one workout each week at close to your projected pace for the event. This will assist your muscles in more easily switching between glycogen and fat fuel sources.

Paul O’Brien is a personal trainer and life coach based in Westport.