Frank Horwill



  • These articles were first published many year's ago and whilst some are as relevant today as they were when new, many are now mostly of historical interest as modern research and coaching methods have superseded them.

Your Food: What it Contains

By Frank Horwill

The banana

175g. 76 per cent water. 100 calories. 1g protein. A trace of fat. 26g carbohydrates. 10mg calcium. 0.8mg iron. 230 International Units of Vitamin A. 0.06mg thiamine (B1). 0.07mg riboflavine (B2). 0.8mg niacin (B3). 12mg Vitamin C. 0.5mg/100g sodium. 420mg/100g potassium. High amounts of B6. Good amounts of the amino acid phenyalanine. Also, the amino acid trytophan, tyrosine.

Special notes. Athletes lose potassium in sweat in greater amounts during the summer. The banana is a high glycaemic carbohydrates. (Glucose from it is in the blood very quickly. It’s not a good carbohydrate to boost for a marathon. Ideal for replacing glucose after training. The amino acids listed may be described as minor ergogenic. Suggested quantity per day – one with all meals.

The apple

155g. 85 per cent water. 70 calories. 18mg carbohydrates. 8mg calcium. 0.4mg iron. 50 international Units of Vitamin A. 0.04mg thiamine. 0.02mg riboflavin. 0.1mg niacin. 3mg Vitamin C. 50mg/100g potassium.

Special notes. The apple is a low glycaemic carbohydrate (readily stored as glycogen and should form part of the diet before a marathon). Inferior to the banana nutritionally. Suggested daily intake – one with all meals.

The pear

182g. 83 per cent water. 100 calories. 1g protein. 1g fat. 25g carbohydrates. 13mg calcium. 0.5mg iron. 30 International Units of Vitamin A. 0.04mg thiamine. 0.07mg riboflavine. 0.2mg niacin. 7mg Vitamin C.

Special notes. The pear and the apple contain a vague mineral called boron. Dr James Penland, PhD, at the US Department of Agriculture’s Grand Forks Human Nutrition Research Centre, produced evidence that the eating of two apples and two pears a day, because of their boron content, increased mental ability. An electroencephalogram used on 15 people over the age of 45, clearly showed an increase in alpha waves and a decrease in theta waves. When denied boron, the exact opposite occurred. This was disclovered in 1993. Eat two daily.

The orange

180g. 86 per cent water. 65 calories. 1g protein. 16g carbohydrates. 54mg calcium. 0.5mg iron. 260 I.U. Vitamin A. 0.13mg thiamine. 0.05mg riboflavine. 0.5mg thiamine. 66mg Vitamin C. Contains folic acid used in the manufacture of new red cells. Has 190mg/100g potassium.

Special notes. Females should note the high calcium content of the orange, also its high Vitamin C content. It’s a low glycaemic carbohydrate and should form part of a carb-boosting diet before a marathon. The high Vitamin A content is good for the health of the trachea membranes. Eat three daily, or drink a pint of pure orange juice. Females should also note that folic acid is a major blood-forming agent.


1 cup is 149g. 90 per cent water. 55 calories. 1g protein. 1g fat. 13g carbohydrates. 31mg calcium. 1.5mg iron. 90 I.U. Vitamin A. 0.04mg thiamine. 0.10mg riboflavin. 0.1mg niacin. 88mg Vitamin C.

Special notes. Note the high Vitamin C content of a cup of strawberries, also the good calcium content. It has a far better iron content than the other fruits listed. Some people are allergic to this fruit, especially some asthmatics.