Sports Nutrition

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Building Muscle and Lean Mass: How Much Protein Do You Need? by Dr. James Meschino D.C., M.S.

For many sports, superior muscular strength is an important component of success and performance. As a result most dedicated athletes follow a strength training regime, usually involving weight training equipment, in order to continually increase their muscle power and to guard against muscle atrophy and strength decrements during the off season. Body builders and power lifters are particularly focused on weight training and muscular development as the primary focus of their athletic involvement.

In previous articles, I have explained the key principles of strength training as they apply to various types of sports. There remains little doubt that the most effective way to increase muscular strength and lean mass development is through the implementation of a properly designed weight training program. Weight training stimulates the involved muscles to lay down a increased number of protein contractile bands known as myofilaments. By increasing the number of myofilaments, each muscle fiber can then contract with increased force, thus providing increased strength capacity of the muscle.

A key point is the fact that the new contractile bands (myofilaments) synthesized within each trained muscle fiber are made out of protein. Thus, one of the questions frequently asked by individuals involved in strength training is how much protein should I consume each day to maximize muscle growth and strength? Scientific investigation into this matter has now shown us that the amount of protein one requires is dependent upon their body size and work out program.

As a general rule you can calculate your protein needs by multiplying your weight in pounds by 0.4, 0.5, 0.6, 0.7 or 0.8.

You can estimate your protein need in grams per day by following the steps below:

Step 1 Review the descriptions and values of the following five activity levels and determine which type most accurately reflects your current activity level.

• Sedentary No exercise, no heavy manual labour, work or job.
• Value: 0.4
• Mildly Active 30 minutes of fat burning aerobic exercise 5 to 7 times per week and no heavy manual labour, work or resistance training
  Value: 0.5
• Moderately Active 30 minutes of fat burning aerobic exercise program 5 to 7 times per week and weight training program 3 or more times per week or heavy manual labour job
• Value: 0.6
• More Advanced:Activity Level Minimum of 30 minutes of fat burning aerobic exercise 5 to 7 timer per week and 1 hour of high intensity weight training 5 or more times per week
• Value: 0.7
• Heavy Training More than 90 minutes of weight training 5 or more times per week with additional aerobic participation
  Value: 0.8

Step 2 Determine your activity level type from Step 1, and write its assigned value here: (eg., 0.5)

Step 3 Estimate your protein need in grams per day by multiplying your weight (lbs.) x the assigned value of your activity level type:
Your Weight (lbs.) x Assigned Value =

My protein requirement per day is

Now that you have identified your approximate protein needs in grams per day, become familiar with the following low fat, high–protein foods that are available. It is often difficult to attain your protein goal once you factor in your increased requirement imposed by exercise. Thus, many recreational and elite athletes consume low fat, low carbohydrate protein shakes and protein bars to make it easier to attain their protein requirement.

PROTEIN FOODS WITH LITTLE FAT
FOOD PORTION / gms. OF PROTEIN

• Chicken 3 oz. 27
• Turkey 3 slices: 3 ½ x2 ¾ x 1 ¼ 28
• Chicken ¼ broiled 22.4
• Most fish 3 oz. 20
• Tuna ½ cup 15.9
• Tuna 3 oz. 24
• Oysters 6 medium 15.1
• Egg white -one 7
• Dairy Cottage Cheese 5-6 tbsp. 19.5
• 1% Yogurt of 1% milk 8 oz. 8.5
• Vegetarian
• Soy milk low-fat 8 oz. 4
• Soy cheese low-fat 1 oz. 7
• Kidney Beans ½ cup 7.5
• Rice ½ cup cooked 2.0
• Corn ½ cup 2.5
• Green beans ½ cup 1.0
• Green peas ½ cup 4.0
• Baked Potato 1 medium 3.0
• White bread 1 slice 2.0
• Whole Wheat bread 1 slice 3.0
• Typical breakfast cereal 1 serving 2 – 4
• Saltines 4 crackers 1.0
• Tomatoes 1 medium 1.0
• Banana 1 medium 1.1
• Most fruits 1 serving 0.3 – 0.8
• Bagel 1 medium 7
• Pasta 1 cup cooked 7

You now know how much protein you need per day to optimize your muscle growth and strength development. In a future article I will address the best sources of protein for muscle development, timing of protein intake; and other natural dietary means of creating anabolic drive and maximum muscular strength development.

Copyright 1998 Dr.James Meschino D.C., M.S.

References:

Lemon P.W. et al. Protein requirements and muscle mass/strength changes during intensive training in novice body builders. J. Appl. Physiol 1992; 73 (2) 767-775.

Lemon P.W. et all. Effect of initial muscle glycogen levels on protein catabolism during exercise. J. Appl. Physiol;1980; 48(4): 624-629.

Lemon P.W. Protein and exercise update. Med. Sci. Sports Exer.;1987; 19 (suppl): 179-190.

Friedman J. E. et al. Effect of chronic endurance exercise on retention of dietary protein. Int. J. Sports Med.; 1989; 10:118-123.

Evans W.J. et al. Protein metabolism during exercise. Physician and Sports Med.; 1983; 11:63.

Gontzea I. et al. The influence of muscular activity on nitrogen balance and on the need of man for proteins. Nutr. Rep. Int., 1974; 10:35.

Gontzea I. et al. The influence of adaptation to physical effort on nitrogen balance in man. Nutr. Rep. Int., 1975; 11:231.

Celejowa I. et al. Food intake, nitrogen, and energy balance in Polish weight lifters during a training camp. Nutrition and Metabolism 12:259-274, 1970.

Laritcheva K. A. et al. Study of energy expenditure and protein needs of top weight lifters. In Parizkova and Rogozkin (Eds.). Nutrition, physical fitness, and health; pp. 155-163, University Park Press, Baltimore, 1978.

Hickson Jr. J. F. et al. Human protein intake and metabolism in exercise and sport. In Hickson and Wolinski (Eds.). Nutrition in exercise and sport, pp. 5-35, CPC Press, Boca Raton, 1989.

Grunewald K.K. et al. Commercially marketed Supplements for Bodybuilding Athletes Sports Medicine 1993; 15(2); 90–103.

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Complex Carbohydrates and Athletic Performance by Dr. James Meschino D.C., M.S.

Eating enough complex carbohydrate foods is also important for enhancing athletic performance. Your muscles can absorb and store carbohydrate sugars. The carbohydrates provide some of the energy for physical activity. Regularly exercised muscles can store double the amount of carbohydrate sugar, giving you more strength and endurance.

When a muscle has depleted its reserve of carbohydrate sugars during exercise, it becomes fatigued and soon reaches the point of complete exhaustion. During exercise that requires prolonged endurance (jogging, cycling, swimming), muscles extract carbohydrate sugars from the bloodstream at a rate of 30 to 40 times faster than during rest or light activity. Those sugars are drawn from the liver.

A diet rich in complex carbohydrates keeps the supply of carbohydrate sugar stored in your liver and muscles high. This supply helps prevent your blood sugar levels from falling during exercise.

In marathon running, an empty carbohydrate fuel tank is known as "hitting the wall". Sometimes, at around the 20-mile mark of a 26.2-mile (42 km.) marathon, the runners may begin to slow down, becoming weak and dizzy. Often, they can only walk the last few miles, if they can continue at all. What has happened is that the muscles have exhausted their stores of carbohydrates, and the liver can no longer maintain normal blood sugar levels. The bran and nervous system, deprived of the energy that they need to function properly, may cause so much dizziness that the runner falls. Athletes in many sports can suffer from carbohydrate depletion.

Athletes refer to the intake of a diet rich in complex carbohydrate foods as carbo-loading. By getting regular exercise and eating sufficient carbohydrates you can expand your liver and muscle carbohydrate stores daily to provide you with a winning edge in your athletic pursuits. Carbo-loading will enhance both your endurance fitness level and your muscular strength.

Copyright 1998 Dr. James Meschino D.C., M.S.

References:

Costill D.L., Hargreaves M. Carcohydrate Nutrition and Fatique. Sports Medicine, 1992 13;2:86-92.

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Creatine Supplementation and Muscle Strength by Dr. James Meschino D.C., M.S.

Over the past 5-6 years there has been a growing awareness that creatine supplementation can increase muscle strength and mass (2,3). In 1998 sales of creatine in the Unites States are expected to reach $ 200 million (1).

Creatine is an amino acid that is stored in muscle in the form of creatine phosphate. During explosive or intensive exercise, creatine phosphate is broken down by a specific enzyme to yield creatine, plus phosphate, plus free energy. The free energy released from the breakdown of creatine phosphate is used to re-generate ATP, which is the fuel that powers muscle contraction (2).

The normal daily requirement for creatine is about 2 grams for a 70 kg. person. Animal protein (especially meats) provides half that amount and the other half is synthesized by the liver. A half-pound of raw meat contains about 1 gram of creatine.

A number of recent studies have demonstrated that short-term creatine supplementation increases creatine phosphate stores in skeletal muscle by 10% to 40% (3). This in turn leads to an increase in muscle mass, which is thought to occur from increased protein synthesis as the muscle lays down an increased number of contractile myofilaments (protein bands that contract and generate force). Increased muscular fluid retention may also participate in muscle mass gains (5, 6, 7).

It also appears that creatine supplementation may allow athletes to train harder (due to increased available energy for muscle concentration), which promotes strength gains, and increases muscle size due to hypertrophy (larger muscle fiber size) (2,3).

The established protocol for creatine supplementation involves a loading dosage of 20 to 25 grams per day for the first 5 to 7 days. Typically an athlete will mix a heaping teaspoon of creatine monohydrate crystals into a glass of juice to obtain about 5 grams of creatine. During the loading phase the athlete does this on 4 or 5 occasions throughout the day to attain an intake of 20-25 grams.

After the loading phase is completed the maintenance daily dosage is usually 5 to 10 grams per day. Recent reports suggest taking creatine with glucose (a simple carbohydrate) may increase the amount of creatine absorbed by the muscles. As such, some manufacturers combine creatine with carbohydrates in a premix product to help improve creatine delivery to muscles.

Several studies have shown that creatine supplementation improves performance in repeated bouts of high intensity strength work and repeated sprints, which are requirements for many sports (13, 14, 16, 17, 18).
Significant gains in strength and lean mass often occur in the first 6 weeks of creatine supplementation, when combined with proper training and diet.

In one study, college football players who took creatine supplements for 28 days during resistance and agility training had significant gains in lean mass when compared with players who took a placebo (15).

Individuals may vary in their response to creatine supplementation, but it is not uncommon to see a 5 to 10 lb. increase in weight within the first six weeks.

Approximately 80% of creatine studies have reported a performance-enhancing effect. This is quite impressive when you consider the fact that creatine is not structurally or functionally related to anabolic steroids, and creatine supplements are not banned by the International Olympic Committee or the National Collegiate Athletic Association. Creatine use is based on the same principle as carbohydrate loading in that an athlete is manipulating their dietary intake to optimize muscle creatine phosphate stores for more explosive power and enhanced performance.

As for the safety of creatine supplementation, a 1997 study showed that short-term creatine use (20 grams per day for 5 days) did not increase markers of kidney stress in five healthy men (21). However, individuals with pre-existing kidney disease should be cautious as evidenced by the development of kidney dysfunction in a 25 year old soccer player taking creatine who previously had been treated for focal segmental glomerulosclerosis of the kidney. His kidney function returned to normal when he stopped taking the creatine supplements.

For younger athletes, the safety of creatine supplementation has not yet been investigated. My feeling is that younger athletes should not use creatine, but rely on a proper diet and training to build their bodies during developmental years.

Overall creatine supplementation appears to be safe for healthy adults. It's a low molecular weight compound that is excreted in the kidneys by simple diffusion. In the maintenance phase athletes consume the amount of creatine generally found in the diet.

Due to its effectiveness in improving muscle energy stores and strength, creatine is now being studied as a therapy to reverse muscle wasting after heart surgery and to improve exercise capacity in patients who have chronic heart failure
(10, 11).

Personally, I think creatine is here to stay. It works, and athletes notice differences in their lean muscle mass and strength almost right away. It's been studied for 5 or 6 years and scientific investigation around its use is still quite intensive.


Copyright 1998 Dr. James Meschino D.C., M.S.

References:

1. Kreider RB: Creatine, the next ergogenic supplement? Sportscience Training and Technology. Internet Society for Sports Science. Available at: http://www.sportsci.org/traintech/creatine/rbk.html. Accessed May 5, 1998.

2. Kreider RB: Creatine supplement: analysis of ergogenic value, medical safety, and concerns. Journal of Exercise Physiology Online 1998; 1(1). Available at: http://www.css.edu/users/tboone2/asep/jan3.html. Accessed May 5, 1998.

3. Bramberger M: The magic potion. Sports Illus 1998;88(16):58-65.

4. Bessman SP, Savabi F: The role of the phosphocreatine energy shuttle in exercise and muscle hypertrophy, in: Taylor AW, Gollnick PD, Green HJ (eds), International Series on Sport Sciences: Biochemistry of Exercise VII. Champaign, IL, Human Kinetics, 1988, vol. 19, pp 167-178.

5. Ingwall JS: Creatine and the control of muscle-specific protein synthesis in cardiac and skeletal muscle. Circ. Res 1976;38(5 suppl 1):I115-I123.

6. Sipila I, Rapola J, Simell O, et al: Supplementary creatine as a treatment for gyrate atropy of the choroid and retina. N Engl J Med 1981;304(5):867-870.

7. Almada A, Kreider R, Ferreira M, et al: Effects of calcium-HMB supplementation with or without creatine during training on strength and sprint capacity, abstract. FASEB J 1997; 11:A374.

8. Earnest CP, Snell PG, Rodriguez R et al.: The effect of creatine monohydrate ingestion on anaerobic power indices, muscular strength and body composition. Acta Physiol Scand 1995;153(2):207-209.

9. Burke LM, Pyne DB, Telford RD: Effect or oral creatine supplementation on single-effort sprint performance in elite swimmers. Int. J Sports Nutr 1996;6(3):222-223.

10. Dawson B, Cutler M, Moody A, et al.: Effects of oral creatine loading on single and repeated maximal short sprints. Aust J Sci Med Sports 1995;27(3):56-61.

11. Redondo DR, Dowling EA, Graham BL, et al: The effect of oral creatine monohydrate supplementation on running velocity. Int J Sports Nutr 1996;6(3):213-221.
12. Kreider RB, Ferreira M, Wilson M, et al.: Effects of creatine supplementation on body composition, strength, and sprint performance. Med Sci Sports Exerc 1998;30(1):73-82.

13. Poortmans JR, Auquier H, Renaut V, et al.: A Effect of short-term creatine supplementation on renal responses in men. Eur J Appl Physiol 1997;76(6):566-567.

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Enhancing Exercise Performance With Pre-Game Carbohydrate Intake by Dr. James Meschino D.C., M.S.

Carbohydrates are an important source of energy for sports that involve repeated bouts of explosive power and for long distance events. As this defines most sports, carbohydrate intake is a critical determinant in optimizing athletic performance. A short list of sports that rely on carbohydrate as a predominant energy source include (basketball, soccer, hockey, la crosse, football, tennis, squash, badminton , racquetball, handball, middle and long distance running, swimming, rowing, and cross-country skiing).

For sports of this nature adequate carbohydrate intake before, during and after exercise is associated with enhanced exercise performance. Thus, knowing the right amount, type and timing of carbohydrate helps to provide an athlete with a competitive edge.

The early studies on carbohydrate and exercise performance date back to the late 1960s (Bergstrom et al., 1967), which confirmed the work of Christensen and Hansen, who 30 years earlier had demonstrated the importance of increased dietary carbohydrate for endurance exercise performance. So, at a time when professional athletes were still eating a pre-game steak, research was already in place to suggest that any combination of pasta, rice, bread, vegetables, fruits, peas and beans would have been a better choice to enhance performance.

Recent studies have proven that an athlete's diet should consist of 60-70% carbohydrate calories during heavy training where carbohydrates are a predominant energy source.

The pre-exercise or pre-game meal should consists primarily of carbohydrates and be ingested 3 to 4 hours prior to competition. This should not include a lot of refined sugar products, but rather carbohydrates that don't abruptly cause a rise in blood sugar or insulin concentrations. Good examples include oatmeal, whole wheat bread, whole wheat pasta with tomato sauce , brown rice, most vegetables, most fruits, peas, beans, high fiber breakfast cereals (low in sugar) with low fat milk or yogurt (non fat or 1% milk fat).

The pre-exercise or pre-game carbohydrate meal is intended to expand the liver's carbohydrate reserves, which become the exclusive source of blood sugar during the sport or training session. During exercise the muscles at work extract sugar (carbohydrate) from the bloodstream at rate that is 30-40 times greater than under resting conditions. Thus, to prevent liver carbohydrate depletion and a fall in blood sugar adequate carbohydrate intake 3-4 hours prior to the event is an essential part of optimal sports nutrition. In addition, it is possible that a portion of these carbohydrates can contribute to reloading of the muscles' carbohydrate fuel tank, which is a critical factor in for sports performance as we will discuss.

In one study Sherman et al. demonstrated that ingestion of 312 grams (1,248 calories) of carbohydrate 4 hours prior to strenuous exercise resulted in a 15% improvement in exercise performance. As a side note, no improvement was observed when either 45 grams (180 calories) or 156 grams (624 calories)of carbohydrate was ingested. Therefore the meal must contain a sufficient total number of carbohydrate calories to yield a sports-enhancing effect when strenuous or prolonged exercise is involved.

In contrast to this, carbohydrate ingestion 30 to 60 minutes prior to strenuous exercise has been shown to impair exercise performance. This is believed to be due to the effects of insulin which produce a rapid drop in blood sugar when combined with exercise. Thus, it is undesirable to raise blood insulin levels just prior to strenuous exercise.

For this reason drinking or eating carbohydrates just prior to exercise can be detrimental to performance. The one exception to this rule is fructose sugar. Fructose sugar does not disrupt blood sugar or insulin levels to a significant degree and its ingestion 30 minutes prior to exercise has been shown to enhance exercise performance. For this reason I often suggest to athletes that they ingest up to 20 grams of fructose sugar added to cold water (20-25 ounces) 30 minutes prior to their event. This recommendation is less important for more moderate exercise activities such as recreational walking or for submaximal exercise lasting less than one hour. The general importance of carbohydrates for strenuous or long distance events is that it provides a high octane type of fuel that enables muscles to work at a higher rate of power output. During exercise if muscle carbohydrate stores become depleted, muscle power will suffer. Hence, the athlete slows their pace during long distance events or is unable to achieve or maintain their optimal speed in sports that require repeated bouts of rapid acceleration and sprints.

Prior to exercises of this nature refueling of the liver carbohydrate and muscle carbohydrate fuel tank (glycogen reserves) is crucial to performance capabilities.

Knowing how to replenish carbohydrates during exercise, post exercise and during day to day meal planning is also essential and is discussed in other articles appearing on this site entitled "Essentials of Carbohydrate Replenishment During and After Exercise".

Copyright 1998 Dr. James Meschino D.C., M.S.

References:

Costill DL Hargreaves M. Carbohydrate nutrition and fatigue. Sports Medicine, 1992; 13;2:86-92.

Bergstrom J, Hermansen L, Hultman E, Saltin B. Diet, muscle glycogen and physical performance. Acta Physiologica Scandinavica 71:`140-150, 1967.

Costill DL, Coyle EF, Dalsky G, Evans W, Fink W et al. Effects of elevated plasma FFA and insulin on muscle glycogen usage during exercise. Journal of Applied Physiology 43; 695-699, 1977.

Coyle EF, Coggan AR, Hemmert MK, Ivy JL. Muscle glycogen utilization during prolonged strenuous exercise when fed carbohydrate. Journal of Applied Physiology 61: 165-172,1986.

Coyle EF, Coggan AR, Hemmet MK, Ivy JL. Muscle glycogen utilization during prolonged strenuous exercise when fed carbohydrate. Journal of Applied Physiology
59: 429-433, 1985.

Coyle EF, Hagberg JM, Hurley BF, Martin WH, Eshani AA et al. Carbohydrate feeding during prolonged strenuous exercise can delay fatigue. Journal of Applied Physiology 55: 230-235, 1983.

Hargreaves M, Costill DL, Coggan A, Fink WJ, Nishibata I. Effect of carbohydrate feedings on muscle glycogen utilization and exercise performance. Medicine and Science in Sports and Exercise 16: 219-222, 1984.

Hargreaves M, Costill DL, Fink WJ, King DS, Fielding RA. Effect of pre-exercise carbohydrate feedings on endurance cycling performance. Medicine and Science in Spots and Exercise 19: 33-36, 1987.

Hargreaves M, Costill DL, Katz A, Fink WJ. Effect of fructose ingestion on muscle glycogen usage during exercise. Medicine and Science in Sports and Exercise 17: 360-363, 1985.

Koivisto VA, Karvonen SL, Nikkila EA. Carbohydrate ingestion before exercise: comparison of glucose, fructose and sweet placebo. Journal of Applied Physiology 51: 783-787, 1981.

Sherman WM, Brodowicz G, Wright DA, Allen WK, Simonsen J et al. Effects of 4 h pre-exercise carbohydrate feedings on cycling performance. Medicine and Science in Sports and Exercise 21: 598-604, 1989.

Sherman WM, Costill DL, Fink WJ, Miller JM. The effect of exercise and diet manipulation on muscle glycogen and its subsequent utilization during performance. International Journal of Sports Medicine 2: 114-118, 1981. 

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Essentials Of Carbohydrate Replenishment After Exercise by Dr. James Meschino D.C., M.S.

As reviewed in other articles on this site, carbohydrate nutrition is an important determinant of exercise performance for sports that require repeated bouts of all-out-effort (i.e. hockey shift) and long distance races. Consuming a carbohydrate-rich meal
3-4 hours prior to exercise, a fructose-rich drink 30 minutes prior to exercise and the ingestion of 5-8 ounces of a carbohydrate sports drink every 10-15 minutes during exercise are considered prudent ergogenic (exercise enhancing) strategies in the field of sports nutrition. This applies primarily to sports activities executed at a strenuous level and lasting a minimum of 60-90 minutes.

Once the training session or sports event is over there are two concerns to address with respect to carbohydrate replenishment. First, the craving within the muscle for carbohydrate storage is extremely high in the first 2 to 6 hours following the completion of exercise. Thus, this represents an ideal opportunity to rapidly drive carbohydrates into the muscles' carbohydrate fuel tank (glycogen) thereby helping to prepare the muscle for the next training session or competition.

Secondly, on a more long-term basis it is important to derive sufficient carbohydrate calories from day to day as it requires at least 24 hours to fully refuel the muscles' carbohydrate fuel tank. Very conveniently the size of the muscles' carbohydrate fuel tank doubles with exercise training. So, the key is to completely refuel the tank between training sessions as greater concentrations of muscle glycogen are correlated with better performance. This includes improved ability to perform repeated all-out-sprints, better sustained maximum power in long distance events and the postponement of fatigue. Hence, reloading the muscles' carbohydrate stores to a maximum level is deemed to be very desirable for athletes competing in a wide variety of sports. The ability to store twice as much carbohydrate in trained muscles versus untrained muscles is known as glycogen super compensation, which requires sufficient daily carbohydrate intake. For sports that rely heavily upon carbohydrate energy the athlete's diet should consist of 60-70 percent carbohydrates from day to day.

On a more technical level the rate of post-exercise muscle glycogen storage, when supplied by dietary carbohydrates is reported to be 5 to 8 mmol/kg/hour, which means at least 20 to 24 hours are required for complete restoration of normal muscle glycogen levels. The rate of resynthesis is faster if carbohydrates are consumed immediately following exercise rather than delaying carbohydrate intake by 2 hours. Thus, athletes should ingest carbohydrates as soon after exercise as possible.
Interestingly, in the early post-exercise period the optimal carbohydrate intake appears to be 50 grams every 2 hours aiming for a total carbohydrate intake in 24 hours of 600 grams (2,400 calories) for athletes involved in strenuous training or tournament weekends where carbohydrate demanding sports are involved (i.e. basketball, hockey, swim meets).

Ingestion of simple rather than complex carbohydrates are preferred between games and events scheduled on the same day. Examples include sports drinks, sports bars, pancakes, bread, rice, pasta, potatoes, fruit and fruit juice. Sweet vegetable such as carrots, squash and sweet potatoes are also a consideration. If the next game or race is less than 3 hours following the preceding one, then a complete meal is not recommended. Rather, reliance upon sports drinks, sports bars, fruit juice, fruit and carrot sticks are viable dietary suggestions.
In the event of over training that produces muscle soreness, muscle damage and presence of inflammatory cells, the refueling of muscle carbohydrate (glycogen resynthesis) is reduced, resulting in poorer performance in future events. The effect of muscle damage can be partially overcome by the ingestion of increased amounts of carbohydrate. Thus, athletes should be aware of the potential need of increased dietary carbohydrate following intense, prolonged exercise that produces muscle damage and soreness.
From a metabolic standpoint glucose and sucrose (white sugar) result in faster muscle glycogen resynthesis than fructose, although fructose may be of more benefit in the restoration of liver glycogen.
In summary, in view of the importance of carbohydrate for performance in many sports, the goal of carbohydrate nutrition strategies aimed at before, during and after exercise as well as day to day carbohydrate loading can help to optimize athletic performance, providing an important competitive edge.

Copyright 1998 Dr. James Meschino D.C., M.S.

References:

Costill D.L. and Hargreaves M. Carbohydrate nutrition and fatigue. Sports medicine 1992;13;2:86-92.
Bak JF, Pedersen O. Exercise-enhanced activation of glycogen synthase in human skeletal muscle. American Journal od Physiology 248: E957-E963, 1990.
Blom PCS, Costill DL, Vøllestadt NK. Exhaustive running: inappropriate as a stimulus of muscle glycogen supercompensation. Medicine and Science in Sports and Exercise 19: 398-403, 1987a.
Blom PCS, Høstmark AT, Vaage O, Kardel K, Maehlum S. Effect of different sugar diets on the rate of muscle glycogen synthesis. Medicine and Science in Sports and Exercise 19: 491-496, 1987b.
Burke L, Collier G, Hargreaves M. Effect of glycemic index on muscle glycogen resynthesis following exhaustive exercise. Submitted for publication, 1991.
Costill DL, Pascoe DD, Fink WJ, Robergs RA, Barr SI et al. Impaired muscle glycogen resynthesis after eccentric exercise. Journal of Applied Physiology 69: 46-50, 1990.
Costill DL, Sherman WM, Fink WJ, Maresh C, Witten M et al. The role of dietary carbohydrates in muscle glycogen resynthesis after strenuous running. American Journal of Clinical Nutrition 34: 1831-1836, 1981.
Ivy JL, Katz AL, Cutler CL, Sherman WM, Coyle EF. Muscle glycogen synthesis after exercise: effect of time of carbohydrate ingestion. Journal of Applied Physiology 64: 1480-1485, 1988a
Ivy JL, Lee MC, Broznick JT, Reed MJ. Muscle glycogen storage after different amounts of carbohydrate. Journal of Applied Physiology 65: 2018-2023, 1988b.
Kiens B, Raben AB, Valeur AK, Richter EA. Benefit of dietary simple carbohydrates on the early post-exercise muscle glycogen repletion in male athletes. Medicine and Science in Sports and Exercise 22: S88-1990.
O'Reily KP, Warhol MJ, Fielding RA, Frontera W, Meredith CN et al. Eccentric exercise-induced muscle damage impairs muscle glycogen repletion. Journal of Applied Physiology 64: 252-256, 1987.
Sherman WM, Costill DL, Fink WJ, Hagerman FC, Armstrong LE et al. Effect of a 42.2 km footrace and subsequent rest or exercise on muscle glycogen and enzymes. Journal of Applied Physiology 55: 1219-1224, 21983.
Zachwieja JJ, Costill DL, Pascoe DD, Robergs RA, Fink WJ. Influence of muscle glycogen depletion on the rate of resynthesis. Medicine and Science in Sports and Exercise 23: 44-48, 1991.

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Essentials of Carbohydrate Replenishment During Exercise by Dr. James Meschino D.C., M.S.

As I've described in a previous article on this site, 60-70 percent of an athlete's diet should be comprised of carbohydrate calories where the sport involves repeated bouts of all-out effort and for long distance events. For these events carbohydrate energy represents the predominant energy source for maximum sustained power. Carbohydrate depletion during these events is known to hasten the onset of fatigue and to hinder performance capabilities. As a result athletes should be aware of effective carbohydrate repletion techniques as a means of optimizing their performance. Prior to exercise a carbohydrate rich meal should be consumed 3-4 hours before the game or training session. Thirty minutes prior to exercise 10-20 grams of fructose sugar mixed with 20-25 ounces of water can also maximize carbohydrate availability and utilization, enhancing performance.

Consuming carbohydrates during prolonged exercise events has also been shown to improve performance. Numerous studies have demonstrated increased exercise time to fatigue, power output during exercise and improved sprint performance following prolonged exercise when carbohydrate is ingested during exercise. Carbohydrates ingested during intensive or prolonged exercise are able to maintain blood sugar more effectively , thereby providing an immediate source of carbohydrate energy to the exercising muscle. As a result this strategy spares the rapid breakdown of liver carbohydrate, which is then able to provide blood sugar for a longer period of time during the event. Indeed, a recent report has observed a 59% reduction in liver carbohydrate (glucose) production during prolonged exercise when carbohydrate is ingested. This strategy enables the liver to deliver carbohydrate through the bloodstream as blood sugar, thus the exercising muscle uses up its own carbohydrate stores (glycogen) at a slower rate. Slowing the depletion rate of muscle carbohydrate stores allows the muscle to work at higher levels of power for a longer period of time; hence performance improves.

During prolonged exercise the muscle breaks down carbohydrates as a source of energy at a rate of 1-1.5 grams per minute. Based on a number of studies it appears that athletes need to ingest carbohydrates at a rate that will supply them with carbohydrates at approximately 1 gram per minute. This can be achieved by the ingestion of 600 to 1,000 ml/hour of solutions (drinks) containing 6-10% carbohydrate. This simply means that for every 100 ml of water in a sports drink there should be no more than 6-10 grams of carbohydrate. Any more carbohydrate than this will slow down the rate of gastric emptying and water absorption into the bloodstream. Gastric emptying means the rate at which carbohydrates and fluids pass through the stomach into the small intestine where the maximum amount of absorption into the bloodstream occurs.

Soft drinks, for instance, contain at least 12 grams of carbohydrate per 100 ml of water and, therefore, are not good sports enhancement beverages.

The popular carbohydrate sports enhancement drinks in the marketplace all meet the 6-10% carbohydrate criteria as I have explained it.

As for the type of carbohydrate that is best to include in a sports enhancement drink during competition, there is little difference between maltodextrines (glucose polymers) glucose and sucrose in their metabolic and performance effects during exercise. However, maltodextrin solutions tend to be less sweet, and therefore more palatable, than solutions of only simple sugars. In contrast, fructose ingestion during prolonged exercise does not improve performance. Fructose is the beverage of choice 30 minutes prior to exercise, but not during exercise.

As a general guide as to how to practically apply this information, let me summarize this information in the following way. During a strenuous exercise event that will last for more than 60 minutes, consider drinking 5-8 ounces of a carbohydrate based sports enhancement drink every 10-15 minutes. This will not only provide the right concentration and type of carbohydrates to stave off carbohydrate depletion in your liver, bloodstream and exercising muscles, but also provides an optimal strategy to prevent dehydration. Most of these drinks (i.e. Gatorade) also provide sufficient sodium and/or potassium to prevent hyponatremia which is a loss of sufficient sodium (from sweating) to result in a life-treatening conditioning involving brain swelling and other complications. As a rule usually a minimum of 3 to 4 hours of continuous sweating is required to develop hyponatremia, but it remains a nutritional concern for certain types of sporting events.

In conclusion the use of carbohydrate sports drinks is a proven method to enhance athletic performance in events lasting at least 60-90 minutes, which require repeated bouts of explosive power and in long distance events where maintaining optimal speed is critical to the outcome. Consuming 5-8 ounces of these drinks every 10-15 minutes is the best way to deliver the optimal amount of carbohydrate to the exercising muscle during intense and prolonged activity. As well, colder fluids are absorbed faster than fluids at room temperature. Thus, colder beverages are a better choice for optimal carbohydrate and fluid replenishment.

Copyright 1998 Dr. James Meschino D.C., M.S.

References:

Costill D.L. and Hargreaves M. Carbohydrate nutrition and fatigue. Sports medicine 1992;13;2:86-92.

Bjorkman O, Sahlin K, Hagenfeldt L, Wahren J. Influence of glucose and fructose ingestion on the capacity of long term exercise in well trained men. Clinical Physiology 4: 483-494, 1984.

Coggan AR, Coyle EF. Reversal of fatigue during prolonged exercise by carbohydrate infusion or ingestion. Journal of Applied Physiology 63: 2388-2395, 1987.

Coggan AR, Coyle EF. Effect of carbohydrate feedings during high-intensity exercise. Journal of Applied Physiology 65: 1703-1709, 1988.

Coggan AR, Coylle EF. Metabolism and performing following carbohydrate ingestion late in exercise. Medicine and Science in Sports and Exercise 21: 59-65, 1989.

Coyle EF, Coggan AR, Hemmet MK, Ivy JL. Muscle glycogen utilization during prolonged strenuous exercise when fed carbohydrate. Journal of Applied Physiology
59: 429-433, 1985.

Coyle EF, Hagberg JM, Hurley BF, Martin WH, Eshani AA et al. Carbohydrate feeding during prolonged strenuous exercise can delay fatigue. Journal of Applied Physiology 55: 230-235, 1983.

Hargreaves M, Costill DL, Coggan A, Fink WJ, Nishibata I. Effect of carbohydrate feedings on muscle glycogen utilization and exercise performance. Medicine and Science in Sports and Exercise 16: 219-222, 1984.

Ivy JL, Katz AL, Cutler CL, Sherman WM, Coyle EF. Muscle glycogen synthesis after exercise: effect of time of carbohydrate ingestion. Journal of Applied Physiology 64: 1480-1485, 1988a
Ivy JL, Lee MC, Broznick JT, Reed MJ. Muscle glycogen storage after different amounts of carbohydrate. Journal of Applied Physiology 65: 2018-2023, 1988b.

Michell JB, Costill DL, Houmard JA, Fink WJ, Pascoe DD et al. Influence of carbohydrate dosage on exercise performance and glycogen metabolism. Journal of Applied Physiology 67: 1843-1849, 1898a.

Murray R, Paul GL, Seifert JG, Eddy DE, Halaby GA. The effect of glucose, fructose and sucrose ingestion during exercise. Medicine and Science in Sports and Exercise 21: 275-282, 1989.

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General Nutrition Tips for Athletes by Dr. James Meschino D.C., M.S.

If you are a competitive athlete, you probably don't need advice on training techniques. We can, however, point out a few nutrition tips that will give you an edge over the competition. To begin with, it is especially important for you to eat a diet high in complex carbohydrates. This nutritional program is a perfect way to load your body with carbohydrates everyday. Eat a complex-carbohydrate-only meal three to four hours prior to your daily work out. This will load your liver's carbohydrate fuel tank and help prevent hypoglycemic symptoms from appearing during your workout.

During aerobic exercise, up to 10 percent of your energy comes from the breakdown of muscle tissue protein. Therefore, it is wise to have some protein after your exercise to prevent breakdown of your muscle tissue. Within an hour after your workout, eat either a low-fat flesh or low-fat dairy protein meal. Remember that both of these meals should also contain a substantial amount of complex carbohydrates, which will reload the stores of carbohydrates in your liver and muscles.

About 20 to 30 minutes before your workout, you should drink 13 to 20 ounces of water. You should also drink 8 to 10 ounces of water every 15 minutes during a prolonged training session or competitive marathon race. This helps prevent overheating and dehydration during exercise. Like the water in your car's radiator, the water in your bloodstream transports the heat generated from your exercising muscles to the surface of your body, where it escapes, primarily through sweat. You lose between one and three quarts of water per hour during exercise, so dehydration can occur quite easily. Losing 3-4 percent of your water volume through perspiration can decrease endurance performance by up to 30 percent. Further water loss can result in serious dehydration or even heat stroke. Incidentally, as well as being more refreshing, cold water 50C (or 400F) is absorbed into the bloodstream much faster and more efficiently than water at room temperature.

Profuse sweating also results in the loss of electrolytes and minerals. You should take approximately one gram of salt for every quart of water you drink during exercise to prevent a life-threatening condition known as hyponatremia (very low concentration of sodium in the blood). This is most critical if the event will last more than 2-3 hours.

When your aerobic exercise session ends for the day, replace the fluids in your body just beyond the point of satisfying your thirst. Thirst is a reasonable good indicator of your fluid needs, but by the time you get thirsty during exercise, your blood volume is already down by at least one quart of water. In other words, you are already approaching dehydration. So remember: drink before, during, and after exercise.

The best drink to have after exercise is one part of any juice and three parts of cold soda water. The juice will provide carbohydrates to restore your blood sugar quickly and will also provide potassium to replace what you lost in perspiration. The soda water will re-establish the proper balance of water and electrolytes in your bloodstream. You can also use any of the common carbohydrate sports drinks, which provide similar benefits.

Some recent research indicates that athletes use vitamins B2 and B6 faster than other people. Both of these vitamins are necessary for energy production. Aerobic athletes may also be more likely to sustain oxygen damage to their muscles during exercise. Studies indicate that much of this tissue damage can be minimized by supplementing vitamin E, vitamin C, and beta-carotene in doses of 200-400 I.U., 500-1,000 mg, and 10,000-20,000 I.U., respectively. Therefore, it is advisable that aerobic athletes take a multiple vitamin and mineral tablet to supplement the nutritional program. Be sure that the multiple vitamin you choose contains no more than 5,000 I.U. of vitamin A to prevent the risk of toxicity.

There is no question that good nutrition and fluid replacement have a major impact on athletic performance. Use a sound nutritional program to complement your aerobic-endurance training-capitalize on the competitive edge.

You will find a number of details articles about sports nutrition, training and conditioning in this section of my site. This information will help you train smarter and better, enhance your performance through optimal nutrition and supplementation practices.

Copyright 1998 Dr. James Meschino D.C., M.S.

References:

The Winning Weigh. Meschino and Simon, 1993, Elite Publishing, Toronto.

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Playing Steroid Roulette: Is Mark McGwire Putting Himself at Risk? by Dr. James Meschino, DC, M.S.

The use of anabolic steroids by athletes can be traced back as far as 1954 to the World Weight Lifting Championships in Vienna. During this competition, the Soviet team doctor reportedly told the US team physician that Soviet competitors were taking testosterone. Since then, further experimentation with anabolic drugs has continued in attempts to enhance strength, power and muscle mass in various types of athletes.

The Ben Johnson incident at the 1988 Olympics and the inquiry that followed brought attention to the widespread use of anabolic steroids among athletes competing in many different sports.

IIn recent years, a new anabolic steroid story surfaced. This time it involved slugger Mark McGwire, who broke the home run record set by Roger Maris in 1961. Newspaper reports indicated that McGwire admitted to using a steroid substance called Androstenedione, which can be legally purchased in the United States from many health food stores, sports nutrition centers and drug stores.

Androstenedione is legal because it is not a form of testosterone, but it is the immediate building block of testosterone in the body. From a biochemical standpoint, the more Androstenedione there is available, the more testosterone the body can produce.

Under the influence of higher testosterone levels, muscles respond by synthesizing a greater number of protein contractile bands, known as myofilaments. A greater number of myofilaments within each muscle fiber translates into greater strength and increased muscle size (hypertrophy). Thus, higher levels of testosterone can aid an athlete's strength and muscle mass development in an attempt to go beyond his genetic limitations.

As a result of testosterone's proven anabolic properties, there has been intense interest in developing testosterone-related drugs that can provide athletes with a competitive edge. In 1958, Ciba Pharmaceutical Company released Dianabol (methandrostenolone), a synthetic testosterone. Reports about the efficacy of the drug spread by word-of-mouth throughout the weight lifting community. By the 1964 Olympics, anabolic drugs were being used by almost all athletes in the strength sports.

New federal laws (1990) have made anabolic steroids illegal to possess or distribute in the United States. This is primarily due to the potential health hazards associated with their use. Nevertheless, Dr. Charles Yesalis, world expert on drug use in sports at Penn State University, estimates that 75-90 percent of NFL players have used steroids.

A 1991 survey reported that 5 percent of college athletes admit steroid use, although other reports are as high as 14.7 percent. Even at the high school level, reports suggest that as many as 5-12 percent of young athletes take anabolic steroids.

Traditionally, there have been two ways of using anabolic steroid drugs -- by injectables or by ingesting them orally. As a rule, injectable steroids are most potent because they most closely resemble the body's own testosterone and have been chemically manipulated to deliver an even greater anabolic effect.
When taken orally, the majority of testosterone is partially destroyed by enzymes in the intestinal tract and the liver. As a rule, only 5-10 percent survive degradation to reach the systemic circulation and target tissues, such as muscle fibers.

Oral anabolic steroids, however, have been created by modifying testosterone in such a way as to enhance its longevity in the circulation and slow down its rate of destruction by liver enzymes.

Athletes typically use very high doses of these substances, and this is what adds to the danger of their use. For instance, men requiring testosterone injections for medicinal reasons have received a replacement dose of Dianabol of approximately 15 mg/day; athletes have reported using up to 300 mg/day. Although this drug has not been available for medical use in the United States for over a decade, it is readily obtained through black market sources, and remains one of the most-used oral anabolics. Testosterone enanthate, now used medicinally for some rare diseases and for men with low sperm counts, is typically injected at doses of 75-100 mg/week (250 mg maximum). Athletes may use this drug at 1000 mg or more per week.

The dangers of using these drugs are well documented. For an adolescent boy using synthetic anabolic steroids, the primary risk is accelerated puberty and early closure of the ends of the long bones, thus terminating bone growth and potentially resulting in short stature for the boy.

The oral anabolics are known to cause liver damage. The risk of liver tumors (hepatoma) and peliosis hepatitis (the formation of blood-filled cysts within the liver) increases with oral anabolic use. There are almost 100 cases of liver cancer in steroid users reported to date.

Adverse effects also include a drop in HDL blood levels, which increases the risk of coronary artery disease. Steroids can pathologically enlarge the heart and make blood platelets more sticky, both of which increase risk of heart attacks in athletes. Three cases of stroke have also been reported by athletes taking high doses of steroids.

Early onset prostate cancer is also a risk. High levels of testosterone increase growth of normal prostate cells as well as growth of any cancerous cells that may be present in a dormant state. It's very common for even young men to have cancerous lesions in the prostate gland that may never pose a threat to one's life. The introduction of high levels of testosterone acts as a tumor promoter, encouraging the cancer cells to grow and spread.

Other more peculiar side effects of anabolic drug use involves acne on the face and trunk of the body, impotence, gynecomastia (male development of breasts, due to some testosterone converting to estrogen), and decreased size of the testes. Sodium retention, jaundice and a lower sperm count are also associated with anabolic drug use, as is increased aggressive behavior.

As for Androstenedione and its effects, biochemistry principles suggest that higher levels of Androstenedione will raise testosterone levels, yielding an anabolic effect. To appreciate how this is possible, one need only examine the testosterone synthesis pathway that occurs most predominantly in the male testes. In women, the bulk of testosterone is produced in the adrenal glands via the same pathway, but adult males secrete 6-7 mgs per day of testosterone, whereas women produce only 0.15- 0.4 mg per day (approximately 1/20 the male production). Nevertheless, all testosterone is made from cholesterol through the following biochemical steps:

Cholesterol > Pregnenolone > 17 Hydroxypregnenolone > DHEA > Androstenedione > Testosterone

As for all steroids, the rate-limiting step in testosterone production is the conversion of cholesterol to pregnenolone, which is normally regulated by luteinizing hormone (LH). As can be seen, by ingesting Androstenedione, an athlete bypasses the regulation step of testosterone synthesis (cholesterol > pregnenolone), providing the body with the immediate building block of testosterone.

As a result, testosterone synthesis can be greatly enhanced as the enzyme 17-beta-dehydrogenase readily converts Androstenedione into testosterone. Athletes ingesting Androstenedione claim it achieves this anabolic outcome, although sufficient controlled studies are lacking.

The point is, however, that it is biologically plausible that Androstenedione can significantly elevate testosterone levels. This suggests that it carries similar health hazards as other anabolic drugs. Although it presently is available over the counter at many locations, my personal feeling is that athletes are putting themselves at risk for liver disease, liver cancer, heart disease, stroke, stunted growth, and early prostate cancer by using this substance. Its presence in the marketplace is an attempt to circumvent the Anabolic Steroids Control Act established in November 1990.

Unlike DHEA, which the body can convert into estrogen or testosterone, Androstenedione is converted exclusively into testosterone. Thus, higher testosterone levels and more testosterone-related side effects would likely result from its use. My recommendation is that young athletes avoid this substance until its safety can be established.

Anabolic steroids are dangerous because they impose super-physiological levels of testosterone on the body, which act directly on our genetic blueprints. This unnatural and powerful effect results in an increased risk of premature disease and death in an attempt to gain a competitive edge in a sport or competition.

In contrast, the supplementation of vitamins, minerals and various herbal products at appropriate levels is associated with a variety of positive health benefits, and their safety has been well-established.

As such, supplements must be evaluated individually. Androstenedione supplementation may pose a serious threat to one's life, whereas, for instance, the ingestion of a saw palmetto supplement by a middle-aged man can reverse prostate enlargement and possibly reduce the risk of future prostate cancer.

Copyright 1998 James Meschino D.C., M.S.

References:

1. Friedl, K.E. Performance-enhancing substances: Effects, Risks and Appropriate Alternatives. In Essentials of Strength and Conditioning. Human Kinetics, 1994.
2. Di Pasquale, MG. Drug Use and Detection in Amateur Sports. MG.D. Press, 1984.
3. Marks, B., Marks, A. and Smith, C. Basic Medical Biochemstry. Williams and Wilkins, 1996.
4. Fleck, S.J. Designing Resistance Training Programs. Human Kinetics, 1997.
5. Johnson, F.L., et al. Association of androgenic-anabolic steroid therapy with the development of hepatocellular carcinoma.. Lancet, 1972, Vol.2, pp 1273-1276.
6. National Household Survey on Drug Abuse; Population Estimates 1991. Publication No ADM-92-1887. Rockville, MD: Department of Health and Human Services, 1991.
7. Anderson, W.A. et al. A national survey of alcohol and drug use by college athletes. Physician and Sportsmed 1991;19-91, 104.
8. Yesalis, CE, et al. Athletes' projections of anabolic steroid use. Clin Sports Med 1990;2:155-171.
9. Forbes, G. Steroid users know all the tricks. USA Today, 8 October 1991;3C.
10. Yesalis, C.E. ed. Anabolic Steroids in sport and Exercise. Champaign, IL; Human Kinetics, 1992.
11. Kuipers, H. et al. Influence of anabolic steroids on body composition, blood pressure, lipid profile and liver functions in bodybuilders. Int J Sports Med 1991;12:413-418
12. Matsumoto, A.M. Effects of chronic testosterone administration in normal men. J Clin Endocrin Metabolism 1990;70:282-287
13. Ajache, A.E. Surgical treatment of gynecomastia in the bodybuilder. Plas Reconstruct Surg 1989;83:61-66
14. Noble, R.L. Androgen use by athletes: a possible cancer risk. Canadian Med Assoc j 1984;130:549-550.
15. Larkin, G.L. Carcinoma of the prostate. J Engl J Med 1991:324;18982.
16. Roberts, J.T. Essenhigh, D.M. Adenocarcinoma of prostate in 40-year old bodybuilder. Lancet 1986;2:742.
17. Lenders, J.W.M., et al. Deleterious effects of anabolic steroids on serum lipoproteins, blood pressure, and liver functions in amateur bodybuilders. Int J Sports Med 1988;9:19-23.
18. McKillop, G. Todd, I.C., Ballantyne, D. Increased left ventricular mass in a bodybuilder using anabolic steroids. Br J Sprts Med 1986;20:151-152.
19. De Piccoli, B. et al. Anabolic steroid use in bodybuilders: an echo-cardiographic Study of Left Ventricle Morphology and Function. Int J Sports Med 1991;12:408-412.
20. Longhurst, J.C. et al. Echocardiographic left ventricular masses in distance runners and weightlifters. J App Physiol 1980;48:154-162.
21. Johnson, M. Ramey, E. Ramwell, P. Androgen mediated sensitivity in platelet aggregation. Am J Physiol 1977;232:H381-H385.
22. Everly, R.S. et al. Severe cholestasis associated with stanozolol. Brit Med J 1987;294:612-613.
23. Lin, G.C., Erinoff, L, eds. Anabolic Steroid Abuse. Washington, D.C.: Government Printing Office, 1990.
24. Udry, J.R. et al. Serum androgenic hormones motivate sexual behavior in adolescent boys. Fertility and Sterility 1985;43-90.

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Your Pre-Game Nutrition Plan: The nod goes to Fructose by Dr.James Meschino D.C., M.S.

One of the main breakthroughs in sports performance in the past 15 to 20 years has been the ability to understand what foods and nutrients can best optimize athletic performance.

The longstanding ritual of the pre-game steak has been abandoned by athletes who have otherwise learned that the pre-game meal, eaten 3-4 hours prior to competition or training, should be comprised of mostly complex carbohydrate foods such as pasta, rice, vegetables, fruits, cereal products, potatoes, peas and beans.

The confusion that often arises, however, is what to eat within 30 minutes of competition or an intensive training session. Although researchers continue to debate this issue, some very impressive studies suggest that the ingestion of 15-20 grams of the carbohydrate know as "Fructose" is the best performance enhancing food or drink for all sports that have an endurance component, (long distance running, hockey, soccer, basketball, lacrosse, long distance speed skating, cross-country skiing, long distance swimming, ringette, field hockey etc.)

In 1984 a landmark study by exercise physiologist expert Dr. Costill, revealed that drinking a fructose-rich drink 30 minutes prior to aerobic exercise improved performance by slowing down the depletion of muscle carbohydrate stores.

Studies by E. Price, Koivisto, and Levine have also supported the finding that a pre-workout fructose drink can enhance performance during prolonged bouts of exercise that involve endurance or aerobic energy systems.

All other sugar mixtures tend to acutely increase levels of insulin, which have the effect of reducing blood sugar rapidly once exercise begins. This rapid drop in blood sugar forces your muscles to more quickly deplete their own carbohydrate (sugar) stores. Once depleted, fatigue and exhaustion follow, which greatly impair speed, endurance and performance in general, essentially, muscles run out of high-octane fuel (carbohydrates).

By ingesting fructose, 30 minutes prior to exercise it appears that muscles can burn fructose sugar while sparing their own carbohydrate (sugar) stores for use as a high-octane fuel later in the game or event.

So, in order to increase your exercise time to exhaustion, or to maintain your maximum playing level for as long as possible during a game or practice, consider drinking 200-250 ml. of cold water 30 minutes prior to exercise, adding 15-20 grams of fructose to the water. Some companies make fructose powdered drink mixes (usually lemon and orange flavors).

Copyright 1998 Dr. James Meschino D.C., M.S.

References:

Costill D.L. et al., Effect of carbohydrate feeding on muscle glycogen utilization and exercise performance. Med. Sci. Sports Exerc., 1984. Vol. 16, No 3. pp3345-3350.

Price E., Nutritional Aspects of Heart Disease and Athletics. Contin Educ Syllabus Palmer College of Chiropractic-West Dept. of Physiology and Biochemistry, Sunnyvale California, 1987.

Hawley J. A., Oxidation of carbohydrate Ingested during Prolonged Endurance Exercise. Sports Medicine, Vol. 14, No. 1 pp27-42. July, 1992

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