Written by Team MD
09 October 2017

15NNO48-NUTRITION

Nutrition Notebook

Six Facts to Increase Performance

 

 

1) Caffeinated Coffee Increases Testosterone Levels

 Coffee is good for your metabolism. Coffee drinking increases longevity, elevates testosterone levels, reduces the risk of heart disease and improves blood sugar regulation. A Harvard University study led by Nicole Wedick showed that men who drank caffeinated coffee showed increases in total testosterone and decreases in total and free estradiol (estrogen). Coffee acted as a natural aromatase inhibitor, which prevents the conversion of testosterone to estrogen. Coffee had no effect on serum hormone-binding globulin, which is important for determining the biological activity of sex hormones. Coffee is a healthy beverage for bodybuilders. (Nutrition Journal, 11:86, 2012)

 

2) Glycemic Index: Controversial and Misunderstood

 Glycemic index is a measure of how fast a food increases blood sugar. Consuming low-glycemic index foods reduces the risk of diabetes, cardiovascular disease, breast cancer, inflammation, abnormal blood fats and acne. Critics charge that glycemic index doesn't take into account the variety or quantity of foods in the diet, cooking or food processing methods, or the health effects of specific diets. Thomas Wolever from the University of Toronto, in an editorial, stated that glycemic index represents the effects of specific foods rather than a mixture of foods found in meals. It is an effective tool for helping people and professionals design helpful diets. Glycemic index is an effective method for choosing foods that increase blood sugar rapidly or more slowly. (Nutrition Today, 47: 207-220, 2012)

 

3) Best Fuel Use: Glucose or Galactose

 Glucose is the most important fuel at exercise intensities above 65 percent of maximum effort. Working muscles get glucose from circulating blood glucose, the breakdown of glycogen in the muscles and liver, and conversion of chemicals such as lactate to glucose in the liver. Endurance athletes can replenish circulating carbohydrate stores by consuming beverages or foods before or during exercise. British scientists found that feeding either glucose or galactose before a two-hour exercise on a stationary bike (60 percent of maximum effort) increased carbohydrate use compared to a placebo (fake carbohydrate). However, increased glucose use occurred earlier in exercise, while galactose use occurred later. An athletic fluid-replacement beverage containing glucose and galactose might enhance carbohydrate delivery to muscles during exercise. (Medicine & Science In Sports & Exercise, 44: 1598-1967, 2012)

 

4) Making Healthy Food Choices

 Most athletes know that good nutrition is critical for optimal performance. Unfortunately, they have trouble defining healthy diets. Many give up red meat because they think that it is inconsistent with the athletic diet. In fact, lean red meat is a healthy food choice that provides high-quality protein, iron, zinc and vitamin B-12. Moderate meat consumption boosts red blood cell production and enhances immunity. College athletes typically overuse energy drinks, consuming too much fast food, and drink alcoholic beverages during the season. Learning basic information about nutrition from credible sources can improve performance and health. (Nutrition Today, 47:224-225, 2012)

 

5) Nutritionists Reassess Nitrates

 Nitrates found in bacon, hot dogs and cold cuts are linked to stomach and pancreatic cancer. Nitrates, when consumed from vegetable sources, improve exercise performance by increasing nitric oxide (NO) levels in blood. NO is a gas released by the inner lining of blood vessels (endothelial cells) that helps regulate blood flow, blood pressure, muscle contraction strength and mitochondrial production (mitochondria are the powerhouses of the cell). Several studies found that consuming nitrate-rich beetroot extract before exercise improved endurance performance. A review of literature by University of Texas researchers led by Nathan Bryan concluded that nitrate intake was not linked to stomach cancer and that the value of this nutrient should be reassessed. (Food and Chemical Toxicology, 50: 3646-3665, 2012)

 

6) High Calcium Intake Promotes Fat Use

Several controversial studies have found that increased calcium intake is related to lower body fat levels. Not surprisingly, the dairy industry has jumped on these findings to increase their sales. Several literature reviews concluded that calcium supplements do not help people lose weight, but increasing dietary calcium intake might help. A British study, using a technique called meta-analysis, concluded that high calcium intake has a small effect on weight loss and increases fat oxidation by about 11 percent. Increasing calcium intake might contribute to maintaining a healthy weight. (Obesity Reviews, 13:848-857, 2012)

 

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