Carbohydrates
After a run of about 20 miles many marathon runners “hit the wall” – they literally run out of fuel. To help avoid this, it is useful to understand how we use food for energy. Our main source of fuel is carbohydrate (carbs). As soon as we eat carbs they are broken down to glucose and absorbed into the blood stream. Anything we do not immediately use is stored as glycogen in the muscles and liver. These stores are depleted as we run. To avoid depleted glycogen stores you need to make sure that your diet contains plenty of carbohydrates in the form of pasta, bread, rice and potatoes. Aim for “brown” varieties as these contain higher fibre and provide a more sustained release of energy. They also contain more vitamins and minerals such as B vitamins. These aid with the release of energy from food.
You may find it easier to use a powederd carbohydrate drink that you mix with water. You can use this before during and after training or an event. USN carbo fuel is ideal.
Fats
Fats are also used for energy but are a less efficient source of fuel - they should provide about 20% of your daily calories. Fat is also important as it acts as a carrier for the fat soluble vitamins A, D, E and K. You should aim to eat healthy fats, such as omega 3 oils from fish – 3 times per week and omega 6 oils from nuts and seeds – every day. Take a quality essential fatty acid supplement if you are unable to achieve this. Fats from these sources are also anti inflammatory and may help ease any inflammation caused by injury. Saturated fat from meat and dairy, has been linked to heart disease but remember that some saturated fat is important; it is used to make steroid hormones such as testosterone. Aim for healthy organic sources. Avoid trans fats from processed margarines and deep fried foods – your body can not burn them and they may play a role in cardio vascular disease.
Protein
Protein is used to build muscle. Aim for healthy sources of protein from lean meats but don’t forget the red meats. These contain iron – used to make red blood cells, which transport oxygen around the body. Whey protein has been shown to be highly bio available and is excellent for building muscle. Protein also reduces the rate at which carbohydrate is absorbed, leading to sustained
energy release. Use a quality protein supplement after training such USNs muscle fuel which contains both protein and carbohydrate.
Micro nutrients
Extensive exercise leads to the production of free radicals, these molecules damage DNA and proteins. Antioxidants from fresh fruits and vegetables can quench these free radicals so aim for at least five portions per day but also consider a supplement with bioflavonoids, as these facilitate the uptake of vitamin C. Selenium is an important antioxidant mineral which is often deficient in the diet – consider a supplement of 100 mcg per day. Consider sulphur rich goods such as onions, garlic, beans and cabbage as these aid with detoxification in the liver, help with the metabolism of certain fats and are used in the formation of coenzyme A in energy producing pathways of the body. These energy producing pathways also require copper, iron and coenzyme Q10.
Hydration
It is vital that you consume adequate amounts of water. You need to drink before you feel thirsty. Once you are feeling the thirst it is too late – you are already dehydrated. Ideally use a carbohydrate drink that contains added minerals that can be depleted by endurance training. This will help to avoid cramping. USNs carbo fuel is ideal or you can use USNs Vooma gel sachets. Vooma contains electrolytes which will help you to avoid cramping and muscle fatigue.
Event count down
One week before – to build glycogen stores, increase carbohydrate in the diet - aim for about 60% of total intake, about 8g per kg of body weight per day. Aim for slow release carbohydrate such as brown rice but include lean sources of protein such as fish or chicken. Load up with carbo fuel.
The evening before – top up glycogen stores, aim for a low fat meal, drink plenty of fluids.
On the day – continue to top up glycogen stores, aim for low fat and low protein foods that you find easy to digest. About 1 hour before the event have quick release carbohydrates such as a glucose drink, dried fruit or energy bars.
During the event aim to consume drinks with about 50 g of carbohydrate per hour to keep you fully fuelled.