SAFARI Half Marathon 25th Anniversary

 

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Training & Tips

SAFARI FRUIT & NUTS and Sports

Issued by Sport Science Institute

Proper nutrition forms the basis of physical performance. Not only does it provide the fuel for the physical demands placed on the body from day to day, but nutrition also plays an important role in the formation of new tissue and the repair of existing cells.

Carbohydrates: a source of energy Carbohydrates form a substantial part of a balanced diet and because dried fruit is rich in carbohydrates and low in fat, it is an ideal source of energy. Dried fruit is an instant energy-giver since it contains a large quantity of sugar (fructose and glucose) in an easily assimilated form. This sugar, which accounts for 50 to 70% of dried fruit, neutralises acid and does not cause fat to form in the body.

Carbohydrates are the most efficient and preferred fuel for the body. During exercise, the muscles are fuelled by glucose in the blood and by glycogen, the storage form of glucose, in the muscles and liver. The body's limited energy reserves can only be replenished by regular intake of carbohydrates. Between 54 to 74% of all dried fruit is nutrient-rich carbohydrate. A heaped tablespoon of raisins provides 14,8g of carbohydrates; while 3 dried prunes supply you with 16,7g and 2 pear halves with 22g. A 1/4-cup of currants (33g) contains 22,2g of carbohydrates and the same amount of golden sultanas, 24,3g.

Dried fruit is also rich in fiber, low in sodium and contains iron, which is essential in the fight against anemia. Symptoms of anemia include chronic infections, excessive tiredness and lack of stamina. Glycaemic Index The rate at which energy is made available for use by the body is called the Glycaemic Index (GI). A GI of 70+ is considered high, 55 to 70 are moderate, and less than 55 is low. Carbohydrate foods that break down quickly during digestion have the highest GI factors.

These foods cause a high blood sugar response, thus promoting rapid release of glucose into the blood stream. Carbohydrate foods that break down slowly and release glucose gradually into the blood stream have a low GI factor. Moderate and high GI foods such as raisins (64) and golden sultanas (56) are useful when quick peaks in energy are required, especially during and after exercise.

Low GI foods are desirable when aiming for sustained energy release and smooth blood sugar levels without wild fluctuations. Our muscles usually contain enough glycogen to fuel about 90 to 120 minutes of intense physical activity. Carbohydrates are a limiting factor for any exercise longer than this. However, by maximizing muscle glycogen stores prior to the event (by carbo-loading), greater energy reserves are provided for aerobic activities such as walking, running, aerobic dancing and cycling, but also for anaerobic activities such as tennis, golf, netball, squash and weight training. This results in greater endurance and delayed fatigue. Carbohydrates should be consumed during exercise sessions lasting longer than 90 minutes at an approximate rate of 50g per hour. 3 to 4 times can enhance recovery from heavy training or a competitive event if carbohydrates are consumed in the first hour to two after exercise.

Raisins are a particularly popular choice for athletes and sportsmen since they have a moderate GI and are a compact source of carbohydrate and energy. They are therefore ideal for athletes who may not have a great appetite immediately after training. People practicing sport on a daily basis are advised to follow a diet rich in carbohydrates - 60 to 70 % of their daily food intake and between 5 to 10g per kilogram body weight, depending on the intensity and duration of their training sessions or competitive activity. For many athletes with heavy training schedules and commitments, consuming this amount of carbohydrates in one day can be challenging.

For nutritional advice and tips on how to increase your Carbohydrate intake, click here.