1. The human body, while at rest, expends enough energy to maintain functions that are necessary for life. This process requires a breakdown of energy molecules (Robergs & Kravitz). Broken down energy molecules are then responsible for repairing the body’s cells, maintaining immune response or storing glycogen. Adenosine Triphosphate (ATP) is the body’s source of chemical energy used to carry out cellular work. Intense exercise, like a elite runner, adds to the normal caloric expenditure.
ATP is needed due to the contractions of skeletal muscle, thus more ATP is used (Robergs & Kravitz). It is known that the high increase in caloric expenditure between sedentary individuals and runners is the contractions of skeletal muscle and the energy demands of heart (and skeletal muscles) used during exercise. Furthermore, excess post-exercise oxygen consumption (EPOC), or commonly know as “after-burn,” is the process in which the body attempts to return to pre-workout status (Vella & Kravitz). This process further increases the metabolism and burns more calories. Aerobic exercise has the greatest impact on the after-burn. This would separate sedentary individuals (some that may moderately exercising) and marathon runners. EPOC increases as the intensity or the execise increases – this greatly increases caloric expenditure (Vella & Kravitz).
2. All humans dietarily need Vitamin C. The major function of ascorbic acid is that of an antioxidant, which protect cells and their components from free-radical attack, perioxidation, and cellular damage by acting as a free-radical trap (Spallholz et al. 78, 270). The recommend daily amount (RDA) is 90mg for males and 75mg, and many Americans report using vitamin C supplements (Spallholz et al. 78, 270). However, this supplementation is not needed. Megadoses of vitamin C have yet to be proven helpful or effective (Golanty 303.) Citrus fruits and vegetables are the richest sources of vitamin C (Spallholz et al. 78, 270); and the RDA of vitamin C can easily be reached by eating recommended servings of both fruits and vegetables.
Moreover, vitamin C is a water-soluble nutrient. Excess vitamin C that is not required is excreted through the body. The tolerable upper intake level (TL) for adults is 2,000mg of vitamin C (Thompson & Manore 274). Toxicity is only reached by taking vitamin C supplements. It will lead to prolonged nausea, diarrhea and abdominal cramps (Thompson & Manore 275). It is concluded that only smokers take additional vitamin C through food consumption due to the added oxidative stress the body endures from cigarette chemicals (Spallholz et al. 78, 270).
3. Antioxidant supplementation is not recommended, because they all have serious toxic affects. For example, vitamin A in excess of 6,000 RE daily in infants or 15,000 RE in adults can lead to serious health concerns: headache, insomnia, weight and hair loss, spontaneous abortions and birth defects (Spallholz et al 65). Vitamin E in large doses can intensify coagulation defect in vitamin K deficiency and decrease vitamin A absorption (Spallholz et al 72). These antioxidants are fat-soluble. This means that they build up within the fatty tissue, and not excreted like vitamin C. Toxicity levels are then easy to reach.
Antioxidants like vitamin A, vitamin E, vitamin C and Beta-Carotene are easily obtained by eating fruits and vegetables, while high vitamin E concentrations are found in nuts, vegetable oils and wheat germ (Spallholz et al 65, 72). Supplementation is not recommended and should not be bothered with. Deficiencies are not prevalent in developed countries.
4. Antioxidant supplementation, in low dosages, can be beneficial due to their ability to act like a sponge to soak up cell destroying free radicals. They do this by becoming oxidized themselves when reaction with the toxic species (Spallholz et al. 270). Vitamins tend to protect different parts of the cells. For instance vitamin A protect the cell wall and membranes, while vitamin C protects the fluid like cytoplasm. It is important to consume adequate amount of these vital nutrients in order to stop and prevent cell damage (Spallholz et al. 270). Research as shown that extensive free radical damage can cause many cancers and other dangerous health concerns.