Articles

Group running at Golden Gate Bridge

Choose an article:
Building your Base
IM Race Nutrition Management 101
Triathlete
Competitor Magazine

 


Building your Base
By Duane Franks

 

      Imagine that you are about to construct a new house.  The first thing you would do is build a solid foundation to support the future load of the building.  But let’s say that you were in a hurry or didn’t have solid ground to build on.  Although in your haste, you could still build your abode and decorate it with beautiful landscape, but it might only be a matter of time before that beautiful new dream home would crumble down. 

     Now let’s suppose that the above structure is your triathlon body and you are preparing for what you hope will be your most successful race season ever.  Sound familiar?  Each year, many athletes go into their race seasons with an inadequate base.  This shortfall not only limits their potential for athletic success, it may also predispose them to an increased risk for injury.  This becomes even more critical if the upcoming season will include Ironman distance training.  Our body’s muscular skeletal system, equipped with joints and soft tissue is similar to a building’s wood, metal and concrete understructure. Our nervous system is analogous to the house’s electrical wiring that controls all the articulations of the moving parts. 

     So how do we build a strong base that will support the future stress of training and racing?  That question might be best answered with another question: how are we spending our training time during these winter months? There are three areas of focus that are recommended for the off-season.  These are 1) building a base with longer, slower steady-state workouts, 2) Increasing strength with hills and resistance training, and 3) Improving technique and efficiency of the 3 disciplines by performing correctly executed drills. 

      The key to programming these sessions is the intensity and the progression at which we increase the volume.     As a general rule, it is recommended that the duration of the long weekly run be increased by approximately 5-7%, while cycling time can progress at a more liberal rate of 10-15%.  It is further suggest that with running, we build time duration in a sequence of two steps forward followed by one step back so that every third week is experienced by a slightly shorter run.

     Intensity during this period should be kept within the recovery to low aerobic efforts (approx. 50-67% of maximum HR or 25-45 beats below Lactate/Anaerobic Threshold) on the flats and no higher than mid aerobic (approx. 70-73% of max or 20 beats below LT) while climbing hills.  Remember these are the maximum recommended ranges.  Keep in mind that heart rates are approximately 5-7 beats per minute higher for most triathletes when running compared to the same perceived effort during cycling.  The specific time or miles will depend on several factors including the number of years in the sport, current fitness level, race schedule and the distance of the event?  Most athletes training for Olympic distance are advised to include weekly rides lasting 2-3 hours and runs of up to 90-100 minutes.  Those training for half and full Ironman distance should consider a weekly ride of 3-5 hours and a weekly run building to 2 hours or longer.   Long hilly trail runs during the winter season are a perfect way to log miles with less wear on the muscular-skeletal system.  The added gravity factor will also transfer to faster power gains for future running and cycling.  Swim workouts during the base phase should emphasize longer steady sets at an easy to moderate pace with short recovery intervals. 

     Using our construction analogy, the base period should also include technique drills to hard wire our body’s neuromuscular system -- commonly referred to as muscle memory.   Group rides with experienced cyclists and coached swim workouts are ideal for receiving tips to improve form and efficiency. The off-season is the best time to have your swim stroke evaluated by an experienced swim coach, and if necessary, the right time to make the appropriate changes.  These changes to your stroke early in the year will allow you to make significant improvements in speed later in your program as begin higher quality swim sessions. 

     Your gearing selection for the bike during the base phase should employ lighter gears that allow you to maintain a higher cadence.  Many cyclists will change their rear cassette cluster to one that contains more teeth (i.e.13-27 or more) to accommodate climbing hills in an easier gear.  Begin most cycling sessions with several minutes of one-leg spin drills.  Using a bike stand or rollers are great when the weather or time become a factor. These can also improve your balance and pedal spinning efficiency.  Avoid using your aero bars during the base season.  Riding conventional bars will help develop core strength, skill and stability. Running drills, such as high-knees, butt-kickers and strides should also be added to one run each week.

     The final component to include in your winter program is whole body resistance or strength training.  A well-planned program will incorporate a sequence of stages that include a muscle adaptation phase, followed by an increased strength period and a muscular endurance phase.  Exercises during these phases should emphasize larger, multi-joint movements.  Special attention should also be placed on strengthening the body’s core and postural muscles of the abdomen, spine and hips.  After the base season, strength exercises will evolve into those more suited for the individual triathlon activities.

     Building a solid base as described above is only the beginning of your complete triathlon training program.  The months that follow this period will see an increase in quality training that will build upon this base.   Train smart, be safe and remember to always wear your ‘hard hat’ while on the construction site! 

.:.top


IM Race Nutrition Management 101
By Duane Franks (2006)

Three areas to manage: Energy, Hydration and Electrolytes.

Basic Physiology:
  • At rest 80% of blood flow goes to organs, 20% to muscles.
  • While exercising 80% to working muscles and 20% to organs including digestive system.
  • Fat is main substrate used for energy at rest and during low levels of intensity.
  • Some CHO is required to utilize fats as fuel. CHO is only fuel that can be used by neurological system such as the brain.
  • As the intensity increases a shift occurs with CHO being used as main substrate. At LT efforts, CHO is main fuel source.
  • Glycogen is stored in liver and muscles. Some CHO such as fructose and galactose need to be converted to usable glucose. This occurs in the liver so the process is delayed. However, this process allows for better liver storage of glycogen and ultimately may prevent “bonking”.
  • Maltodextrins or glucose polymers are readily available and can quickly be absorbed and delivered to working muscles for fuel.
  • The body stores enough fats to enable us to run for hundreds of miles.

Carbohydrate Intake
  • The body stores approx. 2000 Kcals CHO in muscle and liver.
  • 22g (88 Kcals) of CHO per hour is believed to be the minimum to elicit a benefit.
  • Most studies have demonstrated that ingestion of an isoenergetic CHO (one source such as glucose) can reach a peak oxidation rate of approximately 1 g. per minute (240 Kcals/hour). However other studies have shown that a mixture of CHO (maltodextrins and fructose) can increase oxidation to 1.8 g. per minute (432 Kcals per hour) for cyclist working at 55% of maximum power for 150 minutes.
  • Many if not most of these studies are conducted under standard laboratory environmental conditions (18-22 C and 55-65 relative humidity), which may represent the typical conditions that athletes compete in.
  • A 2004 review of 22 studies examining the various forms of CHO showed little difference whether the CHO was ingested as solid food (energy bars), soft food (gels) or in beverages (sport drink).

Gastrointestinal Problems
  • A study of 1999 Hawaii Ironman finishers found a high incidence of GI complaints with 45% classified as severe while 7% of the athletes were forced to abandon the competition. A 1988 Ironman study reported nausea and intestinal cramping in 61% and 44% respectively of all athletes either during or immediately after the event.
  • The underlying cause of GI symptoms associated with exercise has been rarely studied and remains speculative.
  • Reduced blood flow to the area is believed to produce hypoxia in the intestinal membrane resulting in damage and discomfort.
  • The intestinal agitation or jarring is widely supported to be the positive direct cause of GI symptoms, including diarrhea.

Race Physiology
  • 600-900 kcals are expended per hour by most triathletes during training or competition.
  • Duane’s thoughts are that we should attempt to replace approx. one third of expended calories.
  • Polar HRM and other technology can help determine individual caloric expenditure but must be properly installed with personal data.
  • Individual variation exists so we need to practice in training first. Be scientific about your approach.
  • Fat & fiber not easily digested and can lead to GI distress for most athletes.
  • CHO is the preferred choice for ingesting during racing.
  • 1000 kcals require approx. 1Liter of water to digest.
  • Some studies have shown a small amount of protein (approx. 20%) with CHO can aid absorption of CHO.
  • Kcals should be ingested frequently in small amounts (every 5-15 minutes) for best absorption. High concentrations of some sugars such as fructose may result in bloating and diarrhea.
  • A combination of galactose, fructose and maltodextrin may be best combination of sugars for immediate and sustained energy.
  • Maltodextrin has been shown to cause less gastric distress during exercise because it does not force the body to send water to the intestine to digest.
  • Products such as Carbo Pro (Sport Quest) uses Maltodextrin as only carbohydrate fuel. Other products, such as Sustained Energy and Perpetuem (Hammer Nutrition) combine Maltodextrin with other complex carbs and glucose polymers along with some protein (see CHO section).
  • One study conducted during an Ironman Triathlon correlated CHO intake with faster times when competitors consumed the maximum or higher amount of CHO that can be absorbed and burned as fuel. Increasing CHO intake from 0.6g / min to maximum of 1 g /min (4 kcals / min) during the event improved performance by 5%. In this study raising CHO higher than 1 g / min did not improve race times.
  • Rate of CHO intake into muscles is less with muscles that are already CHO loaded. Therefore it might be preferred to take in less CHO during the first hour.

Practical Summary
  • CHO intake of 1 g or 4 kcals /min (240-280 kcals / hour) may be the maximum your body can absorb at race efforts. However, recreational athletes working at lower intensities (less than 75% of aerobic capacity) may be able to absorb more due to greater blood flow to GI system?
  • Products such as Carbo Pro or Sustained Energy contain pure unflavored CHO and can be mixed in high concentrations for the bike. Add these to your flavored sport drink. It is possible to mix one water bottle that can hold 1000 + kcals. This can be sipped frequently while on the bike. Be sure to drink enough water along with the CHO. Note: This is food, not to be used as your primary fluid replacement.
  • Solid foods such as bars, sandwiches and fruit should be consumed early on the Ironman bike to be absorbed well before the start of the run. It’s best to break these up in pieces and eat small bites frequently. Bars should be pre-opened to be easier and safer to obtain. Be sure to drink plenty of water to aid absorption of nutrients.
  • Maltodextrin mixed with small amounts of fructose or galactose is the most efficient CHO to ingest if ingested frequently in small amounts. This is preferred especially for athletes competing at higher level of intensities (i.e. elite athletes working at upper aerobic to low LT efforts).
  • Protein intake of up to 50-kcals(12.5 grams)/ hour may help reduce muscle breakdown and spare muscle glycogen. Certain products such as Accelerade and Endurox R4 contain 4:1 CHO/Protein. Total protein ingested during competition should be limited to only 5-15%.
  • It is not recommended to ingest fat during racing. However, some athletes can tolerate small amounts of nut butters when working at lower intensities.
  • A Sport fluid containing 5-6% CHO is recommended if using simple sugars. Some athletes may need to dilute with water to lower concentrations of sucrose, glucose or fructose. Other sport drinks that use complex carbohydrates and glucose polymers can accommodate concentrations of 15-18%.
  • When using gels, it may be preferred to only ingest a half packet or less, more frequently than an entire packet at one time. In an Ironman distance event do not use gels until second half of the bike. This will prevent “flavor fatigue”.
  • If “special needs bags” are provided, use them. Freeze your bottles the night before and they will be cold when you receive them mid way on the bike during an Ironman.
  • Once we determine what works in training, we should only practice every few weeks to avoid getting “burned out” on the product.

Hydration
  • Most endurance athletes are in a perpetual state of dehydration. We routinely underestimate our needs by replacing only 50% of body fluids loss.
  • 1% loss of body water can cause a 5% drop in performance.
  • 4% loss of body water (i.e. 160 lb. loses 6 lbs) can reduce performance by as much as 20-30%.
  • Most serious consequence of dehydration is hyperthermia, which can cause heat exhaustion, heat stroke and even death.
  • Fluid replacement should approximate sweat and urine loss.
  • Sweat loses during hard exercise often average 1 -2 L/hour and may as high as 3 L/hour in hot and or humid environments. Body size and individual physiology will dictate sweat loss with larger athletes sweating more.
  • The maximum volume that can be absorbed is believed to be approx. 2 L/hour.
  • More difficult to ingest fluid while running than cycling.
  • Calculating sweat rate may aid in ability to form a strategy to maintain proper hydration.
    * Sweat Rate = (pre-exercise body weight – post body weight) + fluid intake – urine volume
    * 1 pound of weight loss correlates to 15 fluid ounces (450 ml). 2.2 pounds correlates to 1 Liter.
    * Drink appropriate amounts before, during and after exercise.
  • Strategy to stay hydrated:
  • Pre-exercise:
    * Approx. 17- 20 oz, 2 to 3 hours before activity.
    * Consume another 7 to 10 oz. 10-15 minutes prior to activity
  • One large bike bottle holds approx 22-24 oz.
  • During Exercise:
  • Approx. 16-28 for most athletes and up to 40 - 48 oz per hour (7 to 12 oz. every 10 to 15 min for heavier athletes, or those athletes working at higher percentages of aerobic capacity. Or during severe environmental conditions. (heat & humidity).
  • Develop a hydration strategy based on sweat rate. The goal is to maintain body weight on the bike since it will be difficult to do while running. Use the scale method in training during a variety of conditions.
  • Post Exercise:
    * Rapidly replace lost fluids within 2 hours after exercise.
    * Consume 20 to 24 oz. for every pound body weight lost
  • Signs of Dehydration include:
    Thirst
    Irritability
    Headache
    Weakness
    Dizziness
    Cramps
    Chills
    Vomiting
    Nausea
    Increased HR
    Scanty dark urine
  • It may take up to 2 days to fully replace body water if you become dehydrated.
  • Alcoholic and caffeine beverages are diuretics and therefore should be limited.
  • While most front runners and elite athletes are believed to be dehydrated, Recent studies have shown that a percentage of “mid to back of the pack” marathoners and triathletes are actually over hydrated and may be in danger of dilutional hyponatremia/water intoxication (see below).

Electrolytes -- Include: sodium chloride, potassium, magnesium, and calcium
  • Loss in electrolytes with sweat.
  • Mild reductions in blood levels may cause fatigue, muscle cramps.
  • Severe hyponatremia (serum sodium concentrations of less than 128 – 135 mmol/L) may cause several medical conditions and even death.
  • Hyponatremia is typically caused by over hydrating with water or fluids with inadequate electrolyte make-up. Serious Electrolyte compensation in sweat is highly variable among individuals.
  • The average sweat concentration is approx. 2 grams of sodium chloride per liter with some individuals as low as 1 gram and others as high as 4 grams per liter.
  • Athletes with large amounts of crystallized salt on clothes and skin may require more salt intake to replace sodium losses.
  • Training decreases salt concentration in sweat. However the volume of sweat goes up.
  • The amounts of potassium, magnesium and calcium in sweat are much lower than sodium and less likely to cause cramps.
  • Sport drinks contain 40 mg to 250 mg of sodium and 30 mg to 156 mg of potassium per 8 oz.
  • 1.5 liters of Gatorade will contain only 750 mg of sodium. Gatorade Endurance will contain 1500 mg in 1.5 liters.
  • Electrolyte replacement supplements contain 100 mg to 225 mg of sodium and 25 mg to 85 mg of potassium.
  • Ingesting a small amount of CHO may improve the rate of intestinal uptake of sodium.
  • When using electrolyte supplements, always test in training with small dosages first. If possible, combine electrolyte supplements with sport drink to replenish all that is lost during racing.
  • Eating salty foods in the days before an event and using extra salt from the shaker will help increase the body’s storage and or replenish from earlier workouts.
  • Duane’s tip from the Sherpas of Napal: Consuming 1-2 L of Tonic water with Quinine 24-12 hours before event may help prevent cramps.

Tips to carry and administer nutritional products
  • Mix CHO energy products such as Carbo Pro or Sustained Energy in one large water bottle to be sipped frequently.
  • Gels in individual packets can be stored in Bento Boxes (box that attaches behind bike stem), taped to top tube or consolidated to flasks and attached to handle bars with Velcro. For the run, Individual gel packets can be carried with special race belts that have elastic loops and a small zipper pouch.
  • Energy bars or sandwiches can also be stored in bento boxes or placed in back jersey pockets.
  • Electrolyte supplements (capsules or pills) can be grouped by serving and stored in small (1” x 1”) size zip bags available at office supply stores. These can be carried in the Bento Box on the bike and the small zipper pouch or back jersey for the run.
  • Always take extra gels or electrolytes on the bike in case you drop them.
  • Electrolyte pills or capsules should be stored in plastic bags to keep them from getting wet.
  • Aerodynamic bottles mounted in front of aero bars will make it easier to drink without grabbing for a bottle. Bottles mounted behind the seat have been shown to be less aerodynamic and often fall out.
  • Know what products, especially fluid replacement drinks will offered on the course. Test these products in training. If they do not suit you, develop a strategy to carry or obtain your preferred products. A few minutes lost while you are mixing your own drink at an aid station will be well worth the time lost due to hydration or nutritional problems.
  • Never litter on the racecourse. USAT rules will DQ an athlete for discarding garbage in areas other than aid stations or transition areas. Place the empty wrappers in your back pocket and discard at the aid station or transition area.
  • While on the run, wear your race belt over your top. If ice is served, dump the ice down your front and back so the race belt holds it against your torso to slowly melt. Ice can also be carried under your hat.

Race Day 911
  • An increased HR at same exertion effort and or pace may indicate dehydration.
    * Drink fluid, preferably sport drink with a little CHO and sodium
    * Reduce intensity to allow for absorption of water.
  • A reduced HR at same exertion effort and or pace may indicate low glucose levels.
    * Ingest CHO in the form of gel or solid food (on the bike) and or fluid.
    * Try Cola if in the later stages of the race. Caffeine mobilizes free fatty acids to spare glycogen and is a stimulant. Once beginning cola, you must continue using it for the duration of the race.
    * Reduce intensity to allow absorption of fluid and food.
  • Muscle cramps in working muscles may indicate dehydration and low electrolyte levels.
    * Drink!!!!
    * Take sodium in the form of electrolyte supplement and or sport drink with sufficient electrolyte.
    * If on the bike, stand up and stretch. If on the run stretch and then walk backwards to fire opposite muscle groups.
    * Reduce intensity.
  • Intestinal distress, diarrhea and cramping may be a sign that CHO is too concentrated.
    * Drink water to dilute concentration.
    * Switch from fructose or galactose to Maltodextrin or glucose polymers.
    * Reduce intensity to allow greater blood flow to GI.
  • Golden Rule of Race Day Nutrition:
    Never try anything that you haven’t tested in training!

Pre Race Meal
  • Significant depletion of liver carbohydrate stores occur during 8 + hours of fasting sleep. The purpose of the pre-race meal is to top off liver glycogen stores.
  • Assuming that your last post workout (recovery) meal(s) were adequate, you muscle glycogen stores will be full.
  • Most sports nutritionist a pre-race meal should be approx. 150 – 300 grams of carbohydrate ingested 3 hours before the race start. Or approx. 3-5 gm per kilogram of body weight. Extending beyond 3 hours may have a negative impact on performance.
  • Low Glycemic Index carbohydrate is preferred for longer releasing insulin and less chance of dropping blood glucose (hypoglycemia).
  • Examples of low to moderate glycemic index foods: Apples, all bran, oatmeal, corn, whole grain bread, low-fat yogurt, peanuts, jelly, oranges.
  • A small amount of protein taken may help absorb carbohydrate calories and satiety. Soy protein is Recommended for pre and during activity.
  • 100 – 200 calories of carbohydrate can be consumed 5 –10 minutes before start will help for immediate energy without creating an “insulin rush” and dropping glucose levels.
  • Pre-race hydration should also begin several hours prior to the event. 8-20 oz of fluid consumed 60-90 minutes before with an additional 6-12 oz 5-10 minutes before race start should allow for optimal hydration to begin. Sport drink can be used but should shy away from simple sugar drinks that might cause insulin spike.

References

* American College of Sports Medicine, American Dietetic Association and Dietitians of Canada. Joint Position Statement: Nutrition and Athletic Performance. 2000 pp.2130-2145.

* Armstrong, L. E. Hydration Assessment Techniques. Nutrition Reviews 63:S40-S54, 2005.

* Burns, J., Clarkson, M., Coyle, E.F., Eichner, E.R , Kenny, L.W, Mack, G.W., Murray, R., Passe, D., Prentice, W. and C. Rosenbloom. Why don’t athletes drink enough during exercise, and what can be done about it? Gatorade Sport Science Exchange 12:1-4, 2001.3.

* Casa, D. et al. Journal Athletic Training 35 (2): 212-224, 2004

* Cheung, S.S. and G.G. Sleivert. Multiple triggers for hyperthermic fatigue and exhaustion. Exercise and Sport Science Reviews. Vol. 32, Williams and Williams, Philadelphia, 2004, pp. 100-106.

* Cheuvront, S.N. and M.N.Sawka. Hydration assessment of athletes. Gatorade Sport Science Exchange 18:1-12, 2005.

* Clark, N, Recovery nutrition guidelines, Active.com (on line), 2004

* Coyle, E.E. Fluid and carbohydrate replacement during exercise: how much and why? Gatorade Sport Science Exchange 7:3, 1994.

* Davis, M.J., Lamb, D.R., Pate, R.R., Slentz, C.A., Burgess, W.A. and W.P. Bartolli. Carbohydrate-electrolyte drinks: effects on endurance cycling in the heat. Amercan Journal Clinical Nutrition 48:1023-1030, 1988.

* Dohm GL, et al. Metabolic response to exercise after fasting. J Appl Physio 1986;61:1363

* Gil, S.M., Yazaki, E., and D.F. Evens. Aetiology of running-related gastrointestinal dysfunction. Sports Medicine. 26:365-378, 1998.

* Grandjean, A. C., Reimers, K.J. and M.E. Buyckx. Hydration: Issues for the 21st Century. Nutrition Reviews. 61:261-271, 2003.

* Grandjean, A.C. and A. Ruud. Nutrition for Cyclist. Clinics in Sports Medicine. 13:235-246, 1994.

* Hew-Butler, Tamara, D., Sharwood, K., Speedy, D.B., Collins, M. and T. D. Noakes. Ad libitum sodium ingestion does not influence serum sodium concentration during an ironman triathlon. Medicine & Science in Sports & Exercise. 37:S347, 2005.

* Hiller, W., Dierenfield, L.M., Laird, R.H. and D.S. Yamada. Hydration and hyponatremia following ultra endurance exercise. Medicine & Science in Sports & Exercise. 34:S49, 2002.

* Melody, P., Holand, G.J., Loy, S.F., Vincent, W.J., White, T.L., McClaine, A. and E. Sletten. Injuries and illnesses sustained during the eco-challenge ultra-endurance competition. Sports Medicine and Training Rehabilitation. 9:1-13, 1999.

* Mafucci DM, McMurray RG. Toward optimizing the timing of pre-exercise meal. Int J Sport Nutr Exer Metab 2000;10:103

* Peressini, J. Modernization Theory and the Ironman Triathlon. http://www.angelfire.com/ultra/endurance/kines.htm

* Jeukendrup, A. E. Carbohydrate intake during exercise and performance.
Nutrition 20:669-677, 2004.

* Jentjens, R.L.P., Achten, J. and A.E. Jeukendrup. High oxidation rates from combined carbohydrates ingested during exercise. Medicine & Science in Sports & Exercise. 36:1551-1558, 2004.

* Jeukendrup, A.E., Anton, J.M., Wagenmakers, J.H., Stegen, C.H., Annemie, P. G., Brouns, F and W.H.M. Saris. Carbohydrate ingestion can completely suppress endogenous glucose production during exercise. American Journal of Physiology. 276:E672-683, 1999.

* Lambert, G.P., Murray, R. Eddy, D., Scott, W. Laird, R., V. Gisolfi. Intestinal permeability following the 1998 ironman triathlon. Medicine & Science in Sports & Exercise. 31:S318, 1999.

* Lambert, G. P. Role of gastrointestinal permeability in exertional heatstroke. Exercise and Sport Science Reviews. Vol. 32, Williams and Williams, Philadelphia, 2004, pp. 185-190.

* Lopez, A.A., Preziosi, J.P., Chateau, P., Auguste, P. and O. Plique. Digestive disorders of self medication observed during a competition in endurance athletes. Gastroenterologie Clinique et Biolique. 18:317-322, 1994.

* Montain, S. J., Sawka, M.N. and C. B. Wenger. Hyponatremia associated with exercise: risk factors and pathogensis. Exercise and Sport Science Reviews. Vol. 29, Williams and Williams, Philadelphia, 2001, pp. 113-117.

* Noakes, T.D., Sharwood, K., Speedy, D.B., Hew-Butler, T.D., Reid, S. and J.P. Dugas. Dehydration prevents the development of hyponatremic encephalopathy during exercise: evidence from 1423 weighed competitive athletic performances: Medicine & Science in Sports & Exercise. 37:S348, 2005.

* Opplinger, R.A. and C. Bartlok. Hydration testing in athletes. Sports Medicine. 32:959-971, 2002.

* Pahnke, M.D., Trinity, J.D., Zachwieja, J.J., Stofan, J.R., Hiller, D. and E. Coyle. Sodium balance and sweat loss during the Hawaii ironman triathlon. Medicine & Science in Sports & Exercise. 37:S347-S348, 2005.

* Peters, H.P.F., Bos, M., Seebregts, L., Akkermans, L., van Berge Hengouwen, G.P., Bol, E., Mosterd, W.L. and W.R. de Vries. Gastointestinal symptoms in long-distance runners, cyclists and triathletes: prevalence, medication, and etiology. American Journal of Gastroenterol 94:1570-1581, 1999.

* Sawka, M.N., Cheuvront, S.N. and R. Carter III. Human Water Needs. Nutrition Reviews. 63:S30-S39, 2005.

* Sawka, M.N. and S.J. Montain. Fluid and electrolyte supplementation for exercise heat stress. American Journal of Clinical Nutrition. 2:564S-572S, 2000.

* Shirreffs, S.M. The importance of good hydration for work and exercise performance. Nutrition Reviews. 63:S14-S21, 2005.

* Simoni, C.R., de Fatima, Malavasi, L.M., Possamai, C.L. and E.C. Silva. Competition symptoms reported by triathletes. Medicine & Science in Sports & Exercise. 37:S14-S15, 2005.

* Smetanka, R.D., Lambert, G.P., Murray, R., Eddy, D., Horn, M. and C.V. Gisolfi. Gastrointestinal permeability of runners following the 1996 Chicago marathon. Medicine & Science in Sports & Exercise. 29:131, 1997.

* Speedy, D.B., Noakes, T.D., Rogers, I.R., Thompson, J.M., Campbell, G.D., Kuttner, J.A., Boswell, R.D., Wright, S. and Mark Hamlin. Hyponatremia in ultradistance triathletes. . Medicine & Science in Sports & Exercise. 31:809-815, 1999.

* Tsinitzas, O., Williams, C., Wilson, W., Jackie Burrin. Influence of carbohydrate early in exercise on endurance running capacity. Medicine & Science in Sports & Exercise. 28:1373-1379, 1996.

* Van Nieuwenhoven, M.A., Brummer, R.J.M. and F. Brouns. Gastrointestinal function during exercise: comparison of water, sports drink, and sports drink with caffeine. Journal of Applied Physiology. 89:1079-1085, 1999.

* Wallis, G.A., Rolands, D.S., Shaw, C. and R.L.P.G Jentjens. Oxidation of combined ingestion of Maltodextrins and fructose during exercise. Medicine & Science in Sports & Exercise. 37:426-432, 2005.

* Wilson, CF, Sports Nutrition Article (on line), 2003

* Yamamoto, A., Iwane, H., Shimomitsu, T., Odagiri, Y., Hamaoka, T., Katsumura, T. and J. Fujinami. The effect of dehydration on exhaustive mood state following an ultraendurance race. Medicine & Science in Sports & Exercise. 28:S134, 1996.


.:.top



Triathlete
Click the thumbnails to read the pages.



Competitor Magazine
Click the thumbnails to read the pages.


.:.top