Free Radicals


By William Misner, Ph.D.

William Misner, Ph.D.
William Misner, Ph.D.
From 1996 until his retirement in 2006, Dr. Bill worked full-time as Director of Research & Development at Hammer Nutrition. Among his many accomplishments, both academically and athletically, he is an AAMA Board Certified Alternative Medicine Practitioner and the author of "What Should I Eat? A Food-Endowed Prescription For Well Being".
Oxygen has the capacity to be both friend and foe. When energy fuels are metabolized in the presence of O2, 5% of them create molecules that contain an odd number of electrons. If free radicals (FR's) are not neutralized by on site antioxidant body stores immediately, tissue damage occurs to absolutely every cell membrane touched by these imbalanced molecular wrecking machines. Some theorize soreness and stiffness result because free radicals and waste metabolites build up during either prolonged or intense exercise. The more volume oxygen that passes into our physiology for energy fuel metabolism, the more increased free-radical-fatigue symptoms may be experienced.

An athlete may increase the volume of oxygen intake enough to bring about free radical accumulative stress symptoms under the following conditions:
  1. Athletes who exercise above their present fitness state. (Training induces higher tissue antioxidant stores; fit athletes are able to intake higher amounts of oxygen and metabolize more energy with less free radical build-up.)

  2. Athletes who exercise more than 90 minutes. (As muscle glycogen stores begin to deplete, free radical damages increase.)

  3. Athletes who inspire high amounts of oxygen in a relatively short space of time. Interval sessions, fartleks, and hill repeats significantly raise the rate of energy metabolite flux, free radicals, and waste products. The body's endogenous cellular antioxidant stores are not capable of meeting and disposing of the excessive harmful oxygen-induced metabolic byproducts.


When a sedentary athlete begins to exercise, from a slow aerobic pace to an anaerobic pace, free radical production increases from as little as 12 times to as high as 20 times their resting rate (Brooks 1984). The longer or faster the athlete exercises, the more increased proportionate oxygen-induced free radicals are produced causing tissue damages, fatigue, swelling, and pain. This is called "The Univalent Reduction Pathway," which produces massive amounts of superoxides, hydroperoxides, and hydroxyl free radicals during prolonged or intense metabolic activity. The conversion of blood sugar, muscle glycogen, and fatty acids occur by oxidation. During this process pairs of hydrogen atoms are released like guided missiles, resembling a minute micro-level war causing devastating destruction to underlying tissues and cells.

Damages "felt" from non-neutralized free radicals may result in stiffness, soreness, lethargy, and lack of motivation the day following an intense effort. From 95% of all O2 inhaled, no free radicals are released during fuel-conversion, but 5% of the inspired volume is very "dirty" with excessive FR's (Ernster 1986). Every 5 minutes during cycling or running, 15-20 breaths out of every 350-400 inhaled breaths releases a whooping 100% volume of free radical components into the cellular tissues, where body stores of antioxidants must immediately meet and neutralize them as they are produced. As the body stores of antioxidants are recruited and spent during prolonged duration or intense exercise, free radicals are permitted free reign to devastate and damage tissues, creating more free radicals as they circulate within the athlete's exercising muscles.

The human body's natural means of defense against FR damages prepares by store three antioxidants for this purpose: Catalase, Super Oxide Dismutase (SOD), and Glutathione Peroxidase. It is unfortunate that most endurance athletes abuse their physiology to the extent that antioxidant stores are overcome free radical build up, and are forced to either "Rest" or struggle with lost training time from an overuse injury. The mechanism for maximal free radical build-up is the more intense an athlete exercises, the more free radical damages accrue within cellular tissues. Serum Malonaldehyde levels increase proportionate to the volume of oxygen inspired for metabolism in relationship to diminished time intervals. Lovlin, et al, (1987) measured plasma levels of Malonaldehyde (MDA), markers of free radical build up, as noted above. During an all-out 100% maximum oxygen consumption (VO2 Max), they found an increase of +26% more free radicals than could be neutralized immediately by body-stored antioxidants. When these same subjects exercised at an easy 40% effort (VO2 Max), they were actually found to be have -10% less in free radical accumulates than during their sedentary state. This is the scientific basis for "hard-easy" training protocols, and why athletes should back off when A.M. resting heart rate (HR) is +8 beats above normal waking HR or a +10% higher HR than normal.


Free radicals get into to all of us from air pollution, water pollution, herbicides, pesticides, food biodegradation, fat rancidity, ultra-violet radiation, and electro-magnetic pollution.

  1. Train beyond 90 minutes duration
  2. Employ interval training methods (above 80% VO2 Max)
  3. Have a high body fat percentage (above 15%- males, above 20% females)
  4. Eat Animal Meats and Dairy Products
  5. AGE--->Older=More Free Radicals (above 40)
  6. SIZE-->Bigger=More Free Radicals (above 200 lbs)


Bagchi (1997) assessed the free radical scavenging capacity of several exogenous substrates and concluded the following data:

SUBSTRATE FR NEUTRALIZATION RATE: Vitamin C 12-19%, Vitamin E(Succinate) 36-44%, Grape Seed Extract 78-81%, Super Oxide Dismutase & Catalase 83%

Animal studies show that a single bout of intense exercise to exhaustion reduces muscle Glutathione, one of the 3 major antioxidant body stores against free radical accumulation, by a huge 40%! (Pyke 1986) Autopsies on some of these animal subjects revealed that, in fact, their glutathione stores were eventually overcome, resulting in extensive muscle cell damage. A single workout does not usually accrue that degree of FR damages, but over time, and with extensive overuse from either quality of performance, or repetitive endurance sessions, the athlete's body is destined to fail in proportion to the accumulated free radical build-up within tissues.

Hammer Nutrition Super AO Product

Super AO contains the following ingredients:

SUPER OXIDE DISMUTASE (SOD) - 5000 McCord-Fridovich Units enteric-coated for optimal absorption availability to deep muscle cell tissues where free radicals tend to accumulate. SOD is responsible for neutralizing the most common free radical known as superoxide. It also aids the bodys utilization of the minerals copper, zinc, and manganese.

GRAPE SEED EXTRACT (GSE)  100 mg. Proanthocynidins or group of polyphenolyic bioflavanoids (a.k.a. OPCs) are observed to biologically protect and act against all chemo-reactive oxygen-free radicals. GSE is 50 times more effective than vitamin C and 20 times more potent than vitamin E in neutralizing accumulating free radical tissue invaders! In addition, the OPCs in Grade Seed Extract help strengthen and repair connective tissue and are excellent anti-inflammatories.

GLUTATHIONE  100 mg. Normally produced by the human body from n-acetyl cysteine. Body glutathione stores are seen to decline with age, and have been suggested as a method for measuring the degenerative aging process. Along with the mineral selenium, it forms the enzyme glutathione peroxidase, which, along with SOD, is one of the bodys endogenous antioxidants, and perhaps the most important one of all. Glutathione is also part of another enzyme, which has liver protecting qualities. It protects individual cells as well as the tissues of nearly the entire body and is an important nutrient in helping with the prevention of cancer, particularly liver cancer. One study goes so far as to suggest that the more glutathione tissue-stores present, the more years the individual has to live. (Varyshkin 1981).

GINKGO BILOBA  50 mg. This is an herb best known for its ability to enhance circulation and increase the supply of oxygen to the entire body. This allows it to help relieve muscle pain in addition to its antioxidant benefits. A potential benefit of increased circulation is the ability to speed delivery of antioxidants throughout the body in addition to helping eliminate metabolic wastes more quickly.

GOTU KOLA  50 mg. This is another herb that has antioxidant capabilities as well aiding in increasing circulation. It is helpful in decreasing fatigue and neutralizing blood acids and is useful for optimal heart and liver function.

VINPOCETINE  5 mg. This nutrient is chemically related to, and derived from vincamine, an alkaloid found in the periwinkle plant. Experiments with vinpocetine indicate that it can dilate blood vessels, enhance circulation in the brain, improve oxygen utilization, make red blood cells more pliable, and inhibit aggregation of platelets. Vinpocetine also has antioxidant properties. All three nutrients, in addition to their own antioxidant benefits, provide circulatory support for each of the free radical scavenging agents  SOD, Grape Seed Extract, and Glutathione.


Brooks, G.A., Fahey, T.D., EXERCISE PHYSIOLOGY, New York,: John Wiley & Sons, 1984.

Ernster, L., Oxygen as an environmental poison, CHEMICAL SCRIPTA, 1986;26:525-534.

Lovlin, R., et al., Are indices of free radical damage related to exercise intensity, EUR J APPL PHYSIOL, 1987;56:3,313-316.

Bagchi, D., et al., Oxygen free radical scavenging abilities of vitamins C and E, and a grape seed proanthocynidin extract in vitro, RES COMMUN MOL PATHOL PHARMOCOL, 1997;95:2, 179-189.

Pyke, S., et al., A severe depletion in liver glutathione during physical exercise, BIOCHEM BIOPHYS RES COMM, 1986;139:926-931.

Varyshkin, S., et al., Blood glutathione: a biochemical index of human aging, FED PROC AM SOC EXP BIOL,1981;40:3179.

Colgan, M., "Effects of multinutrient supplementation on athletic performance," In Katch, F.I., ed., SPORT, HEALTH, AND NUTRITION, Champaign, Ill:Human Kinetics, 1986,Chapter 3.
Knowledge Search