Although muscle cramps and fatigue are very common problems encountered by ultrarunners, there are several other related problems that can often be dealt with successfully through biochemical approaches. These problems include gastrointestinal distress and blisters.
Distance Running - Prevent Upper GI Distress with H2 Blockers
A common problem among distance runners is upper GI distress. This manifests in different ways: bloating, belching, heartburn, or vomiting. Not everyone experiences the same symptoms or all these symptoms. In more severe cases, the stomach empties very slowly (gastroparesis), and nutrients and water fail to enter the bloodstream. If this goes on for more than an hour or two, mitochondria start dying because of carbohydrate and/or electrolyte depletion. In a race this typically leads to severe fatigue and/or a seriously slowed pace. Consuming more than 100 grams of carbohydrate per quart of water or more than 100 grams per hour (for a 150 pound runner) is a frequent cause of upper GI distress. Upper GI distress is sometimes also attributed to sodium deficiency/depletion—especially in warm temperatures or during high exertional output.
There are presumably other causes of upper GI distress, because many runners encounter the problem even in cool weather and when consuming only 60 grams of carbohydrate per quart of water. Stress—either everyday emotional stress or race day stress—is one very likely cause. Drugs that block H2 receptors in the stomach, such as famotidine (Pepsid), cimetidine (Tagamet), or ranitidine (Zantac), offer a promising way to prevent this problem. Upper GI distress is often interpreted as gastroparesis (failure of the stomach to empty), whereas H2 blockers are generally considered to be a treatment for heartburn or gastroesophageal reflux (GER), so it may initially seem counterintuitive that H2 blockers should be beneficial. However, H2 receptors are histamine receptors, and in the stomach, histamine is a by-product of stress (physical or mental). It is therefore logical that H2 blockers could prevent upper GI distress by interfering with the response to stress in the stomach.
Long distance runners who occasionally experience upper GI distress may want to experiment with famotidine as a prophylactic (10 to 20 mg before a race, and again at 12 hour intervals for longer races). It is available over the counter, has relatively few side effects, and is generally well-tolerated. There are some reports that proton pump inhibitors (PPIs) may also work to prevent upper GI distress. In fact PPIs have been shown to reduce gastrointestinal bleeding in ultrarunners [Thalmann, M., Sodeck, G. H., Kavouras, S., Matalas, A., Skenderi, K., Yiannakouris, N. et al. (2006) “Proton pump inhibition prevents gastrointestinal bleeding in ultra-marathon runners: A randomized, double blinded, placebo controlled study. British Journal of Sports Medicine, 40(4), 359-362]. These drugs are another treatment for GER, and so they may also be blocking the stress response in the stomach. PPIs require a longer course of treatment, and have undesirable side effects when taken over prolonged time. An H2 blocker like famotidine is probably a better choice unless a runner frequently suffers GER when not running.
Distance Running - Avoid Overhydration and Blisters
It may come as a surprise to learn that many blisters experienced by trained runners really result from overhydration, or in some cases, electrolyte imbalance. Think about it. Your body does its best to keep optimal electrolyte concentrations in your muscles. If your water intake is too high, your body attempts to deal with the problem by shunting excess water into the spaces between your cells. Gravity makes this effect more pronounced in your extremities—hence "sausage fingers", swollen feet, and ultimately blisters.
Runners who regularly experience blisters (even while training) should carefully examine whether they have sufficient potassium in their regular diet or whether they may be routinely overhydrating. There are indications that regular soaking of feet in brewed black tea can help avoid blisters because the tannic acid in tea dries and toughens the skin and outermost tissues. Runners who commonly experience blisters only on race day should consider whether they may be overhydrating in the days immediately leading up to races. Runners who only occasionally experience sausage fingers, swollen feet, or blisters can use these symptoms as a signal to decrease fluid intake and/or possibly increase potassium intake at the time. This will improve muscle performance, as well as help avoid hyponatremia.
Endurance Athletes - Get Enough Vitamins and Minerals
Endurance athletes need elevated quantities of most vitamins and minerals. Vitamins and minerals should ideally come from diet. (Your mom DID tell you to eat your fruits and vegetables, didn't she?) You should also be taking a daily performance multivitamin as insurance. Table 1 lists recommended vitamin and mineral supplement levels for most athletes.
Table 1. Recommended Vitamin/Mineral Supplement Levels for Athletes
|Vitamin A||3500 iu||3500 iu|
|Thiamine (Vit. B1)||5 mg||5 mg|
|Riboflavin (Vit. B2)||5 mg||5 mg|
|Niacin||50 mg||50 mg|
|Folate||400 mcg||400 mcg|
|Vitamin B6||5 mg||5 mg|
|Vitamin B12||30 mcg||30 mcg|
|Biotin||30 mcg||30 mcg|
|Pantothenic Acid||20 mg||20 mg|
|Vitamin C||400 mg||400 mg|
|Vitamin D||400 iu||400 iu|
|Vitamin E||200 iu||200 iu|
|Vitamin K||25 mcg||25 mcg|
|Calcium||200 mg||1200 mg|
|Iron||8 mg||18 mg|
|Magnesium||200 mg||200 mg|
|Zinc||40 mg||40 mg|
|Chromium||150 mcg||150 mcg|
|Iodine||150 mcg||150 mcg|
|Copper||4 mg||4 mg|
|Selenium||80 mcg||80 mcg|
|Manganese||3.5 mg||3.5 mg|
|Molybdenum||160 mcg||160 mcg|
|Nickel||5 mcg||5 mcg|
|Vanadium||10 mcg||10 mcg|
|Boron||100 mcg||100 mcg|
A few of these deserve special mention—particularly calcium, zinc, iron, Vitamins D and C, and antioxidants. Both male and female athletes of all ages need 1200 mg of calcium per day. Athletes consuming less than this amount are at increased risk for stress fractures. Women should probably supplement with 1200 mg calcium because women seem to be less effective than men at getting calcium from regular diet. Also consumption of more than 1200 mg/day does not seem to pose any health risk for women.
Excessive calcium correlates with increased the risk for prostate cancer in men. Men should therefore estimate their total dietary calcium intake from dairy products, multivitamin, etc., and then supplement with as much calcium as necessary to achieve 1200 mg/day when training. Both male and female athletes need to make sure they get sufficient Vitamin D, since Vitamin D is essential for incorporating calcium into bone. Large quantities of zinc are lost in perspiration. Therefore both male and female adult athletes of all ages need 40 mg of zinc per day. This level is particularly helpful in maintaining appropriate amounts of testosterone needed for optimal male athletic performance. Vitamin C has largely been debunked as an immune supplement in the average population, but a number of studies have demonstrated it is beneficial to the immune systems of athletes.
In addition, the antioxidant effects of Vitamin C may also be protective. Running appears to deplete iron in the human body. There is not a big enough effect to justify supplementation in most men, but vegetarian and female athletes should make sure they consume 18 mg iron per day. Endurance exercise imposes additional oxidative stress on the human body. Endurance athletes should therefore try to consume large quantities of fruits and vegetables that contain antioxidants. They should also make sure to get adequate amounts of vitamins A, C, E, and (as noted earlier) CoQ10.
The strategies outlined here are no substitute for proper training and everyday nutrition. But if you are a runner who occasionally suffers from muscle cramps, severe fatigue, blisters, or stomach upset, one or more of these strategies might just keep you upright and running efficiently in your next event!
Dr Andrew Murray 2010.