Replace What You Lose or What You Can Assimilate? How to Fuel Successfully (Hint: Less in better than more!)

By: Bill Misner, PhD

A survey of fluids, fuels, and electrolytes protocols vary remarkably among endurance athletes. Here are some of the variations we have observed:

SUMMARY

Our point is that less is better than more and that performance optimal fluid-fuel-electrolytes dose is accurately determined by trial and error. This means that an athlete's weight before and after prolonged training of -2% weight loss after the workout is indicative of positive optimal hydration balance. At the rate of 3% or more post-workout weight loss, dehydration takes a toll in terms of inhibited nutrient delivery, waste removal, overheating issues, malaise, muscle cramps, bloating, gastric upset, and premature fatigue. Nearly the same symptoms reoccur when fluid intake exceeds 1% body weight gain. Here is where some get by with such over hydration issues, while others immediately suffer all of the above or more or at worst scenario are code-4'd to the hospital emergency room with dilutional hyponatremia.

There are persons and organizations telling athletes to consume what you lose because they argue that it needs be replaced immediately in the event. It cannot be replaced 100% but only around 20-30% of the highest absorbed substance. Think about this statement: At an easy 60-85% volume maximal O2 rate aerobic pace, rate of metabolism increases from a sedentary state between 1200-2000%. The body is then induced to survive. Blood volume is routed to working muscles, fluids are lost to evaporative cooling through capillary beds, oxygen is routed to the brain, heart, and a few of our internal organs. Oddly, it is not so directly focused on fluid, fuel, and electrolyte replacement, as some of the "Experts" so advise.

The body sensitizes release of specific hormones in the circulation anticipating losses in favor of life-giving, death-preventing survival, neutralizing blood pH, and balancing fluid, fuel, and electrolyte, compensating for all but about 20-30%, which can be replaced P.O. (orally). Rather than start with attempting to replace hourly loss with hourly dose, we suggest small dose portions at between 20-30% of what is lost. There are many individual variations to consider and they may change with age, dose, fuel selection, and training stress. It is our position that the less you take that supports endurance performance goals is the dose that you should train with and race with... and, if it works for you don't try to fix it by taking more than your body can effectually absorb.

More detailed information about proper fueling and all the Hammer Nutrition products can be found in The Endurance Athlete’s Guide To Success. You can download a free copy at www.hammernutrition.com/guide

© 2006, Endurance Marketing Group. This information is copyright protected. Please feel free to distribute this information as long as this copyright notice and EMG's phone number and/or URL are included. Content must remain unchanged and original authorship acknowledged.

 

The role of branched-chain amino acids in sport - by Doug Cook

Twenty amino acids are the building blocks of protein and the “construction material” of muscles, vital organs and virtually every other part of your body’s lean mass. Of the twenty, eleven can be made by the body via the recycling of old amino acids and the use of carbohydrate. The other nine are considered essential since they must be supplied from the food we eat and can not be synthesized by the body. Of these nine, three: leucine, isoleucine and valine, called Branched—Chain Amino Acids (BCAAs) serve as a critical source of muscle energy during exercise as well as a source of building blocks for muscle repair post exercise.

In fact, the very fibers that make up muscles are themselves "constructed" of these BCAAs [35% of total protein]. Unlike other amino acids, which are mostly metabolized in the liver, BCAAs are metabolized in the muscle tissue itself. Without a sufficient supply, your muscles begin to feel tired and sore during exercise. In contrast, a plentiful supply of BCAAs makes you feel energized—and helps muscles recover and rebuild much faster. And during and after exertion, two other amino acids, arginine and glutamine, work to synthesize proteins, remove harmful toxins and strengthen the body’s immune system.

There is a lot of research in the sport nutrition field on the beneficial role of BCAAs. A study in the February 2006 issue of the Journal of Nutrition found that giving athletes a drink containing various doses of amino acids, improved athletic performance based on various measurements. The supplement, a mixture of amino acids that included the branched-chain amino acids, and arginine and glutamine, was studied over time at several daily dose levels for extended periods of time (10, 30, and 90 days). Outcome variables included physical measures [maximal muscle load, biopsies etc] of muscle strength, fatigue and muscle damage, and blood indices of muscle damage and oxygen-carrying capacity. One beneficial effect of the amino acid supplement was a quicker recovery from the muscle fatigue that followed eccentric [negative phase of the contraction] exercise training. A dose-response study of the amino acid mixture at 2.2, 4.4, and 6.6 g/day for one month showed that at the highest dose, indices of blood oxygen-carrying capacity were increased and those of muscle damage were decreased at the end of the trial. When the amino acid mixture was given for 90 days to elite rugby players during training at a dose of 7.2 g/d, a blood-component analysis indicated improvements in the oxygen-carrying capacity of the blood.

During strenuous exercise such as long runs, or cycling, the body begins to decompose proteins and consume BCAAs in order to compensate for insufficient energy sources. The post-competition blood level of BCAAs may be decreased by 20% because of intramuscular BCAAs consumption in hard sports such as marathons, triathlons and cross-country skiing. This is due to the fact that strenuous exercise consumes and damages muscle tissues. However, that damage can be reduced with the use of BCAAs as a supplement and inhibit the lowering of muscular strength by replenishing BCAAs timely before or during the sport activity. Supplying BCAAs before and during exercise helps to spare muscle glycogen and fat and therefore helps to ‘stretch’ their supply of energy during exercise and seems to help maintain stamina and endurance for a longer period of time. Replenishing BCAAs immediately after the sport activity helps with recovery to mitigates muscle damage and to prevent delayed muscle soreness. In addition to BCAAs, arginine and glutamine also have positive effects on the body engaged in sport activities.

Arginine is closely related to the secretion of growth hormone. Growth hormone is important both for muscle building and for muscle repairing. Replenishment of arginine is considered to promote the synthesis of muscle proteins. Glutamine, an amino acid distributed abundantly in muscles, helps the synthesis of muscle proteins and inhibits their breakdown, as is the case with leucine. Since continuation of strenuous exercise requires glutamine in many organs, it is important to replenish glutamine when doing sports.

So how does one get enough BCAAs to take advantages of them? There are specific supplements designed to contained those that have been used in research and contain iso-leucine, leucine, valine and glutamine, and arginine such as Amino Vital™ www.aimo-vital.com . Alternatively, many foods naturally contain BCAAs, specifically dairy foods and whey protein [derived from milk], eggs and red meat such as beef. Getting the most of these important amino acids will require using them in their different forms. During strenuous exercise such as running and cycling, consuming a milk-based beverage is not idea due to delayed emptying and because they are too high in whole proteins and fat. Using a sport drink that contains BCAAs and a good source of carbohydrate such as Amino Vital Endurance™, which allow you take get the benefits of the amino acids, a good source of carbohydrate in an easy to drink and tolerate beverage. Immediately post exercise, you could use a milk-based beverage that not only has BCAAs but all the essential amino acids and carbohydrate which will aid in the synthesis of muscle glycogen and muscle proteins. Acceptable choices would be chocolate milk, a meal replacement drink like Boost™ or Ensure™, a couple of containers of yogurt or a homemade smoothie made with yogurt, milk or whey protein.

Doug Cook, RD MHSc CDE is a clinical dietitian and certified diabetes educator working at St Michael’s Hospital in Toronto. Doug at dc_dietitian@hotmail.com or visit his website www.wellnessnutrition.ca