Matt Poe uses an existing client, "Ned The Golfer", to explain the considerations and fluid requirements for athletes with comments about Gatorade’s new “Endurance Formula”. A Discussion On Fluid Intake and Gatorade's New Endurance Formula By Matt Poe, MS Matt Poe > Let’s pose three questions for this discussion!  First let's look at the profile of "Ned The Golfer"   Beginning weight: 146.5 (66.59kg) Ending weight: 145 (65.91kg) Fluid loss: 2.5 pounds (1.14kg) weight loss (consumed 16 oz of fluid) Sweat rate: 40 oz/hour   PART 1:   Based on the recommendations in the literature what is the average amount of fluid you estimate that Ned requires each day?  How would you recommend Ned obtain this fluid (type of fluid(s), consumed in one sitting/multiple sitting, etc).  THEN, consider the results of the sweat loss test- do your estimates change?  (in other words is Ned a typical sweater, a heavy sweater of a light sweater? Ned lost 1.18 liters (40 oz) of fluid in an hour of exercise.  Based on current research, I would recommend that Ned consume from 5-8 liters of water each day (1).  During golf tournaments in warmer climates I would even recommend 8-10 liters/day as his losses would tend to be higher.   This may seem a bit high but keep in mind that he is outside for prolonged periods in humid and hot conditions both for practice time and during competitions.  Consuming much more than 1.2L/hr can be quite difficult thus consumption before and after practices and competitions is vital (1,2,3).  A 16 oz drink would be perfect prior to exercise as that would meet the 6-8 ml per kg of bodyweight recommendation (2).  Ned appears to be a typical sweater thus my estimates for fluid intake are not affected by this single variable (2).  The main variables that will affect Ned’s loss of fluid are the temperature and humidity and the level of exercise.  More strenuous golf courses/tournaments would require higher levels of consumption.  The research states that negative effects begin to occur after a 2% body mass loss due to sweat loss (2,3,5,7).  Much of the research recommends between 1.2 and 1.6 L/hr as that is close to the gastric emptying rate and much more would cause GI discomfort (3,4).  I would recommend Ned reach these consumption goals via sports drinks that contain the proper electrolyte balance or water while consuming granola, trail mix, or the like (6).   PART 2: Ned decides to spend the next 6 weeks in Miami Florida, and do all of the exercise outside between 8am and 12pm each day.  Again based on research how, if at all, would your recommendations from #1 differ?  According to The Weather Channel website the average temperatures for Miami, FL and Nashville, TN are relatively close during the golf season(8).  The average humidity of those same two cities are relatively close as well over that same time period(9).  The good news here is that Ned will be used to the humidity which is a gigantic hurdle for those who are not acclimatized to the heat and humidity. Considering my original recommendations, if Ned were to encounter warmer days and higher average temperatures in Miami in comparison to Nashville, I would make Ned aware that he might consider an increase in his consumption of fluids by a liter or so to combat these changes. Practicing earlier or later in the day is not a viable option as he will most likely be competing in the hottest parts of the day.   PART 3: Gatorade now markets Gatorade Endurance.  Powerade plans to bring a similar product to the market (it is currently available in some markets).  Is this just marketing hype, or is there actually a physiological benefit for active individuals to utilize these beverages compared to “traditional” Gatorade/Powerade/Cytomax/etc?  Gatorade and Gatorade Endurance do differ in the amount of sodium and potassium.  Gatorade original has 110 mg of sodium and 30 mg of potassium; whereas, the endurance formula has 200 mg of sodium and 90 mg of potassium and 6 mg of calcium and 3 mg of magnesium (10).  These increased levels of nutrients are important during longer, more intense exercise (6).  Based on this information, I would tend to say that there is a physiological benefit from these beverages as opposed to solely being “hype”, but more research seems  to be needed in this area.  There are less expensive options and more expensive options to maximize recovery.  One’s body must be “trained” to utilize the increased nutrients in the endurance formula.   References 1. Sawka MN, Cheuvront SN, Carter R. Human water needs. Nutr Rev.  2005:63;30-39. 2. Shirreffs SM, Sawka MN, Stone M. Water and electrolyte needs forfootball training and match-play. J Sport Sci. 2006:24;699-707. 3. Kovacs MS. A review of fluid and hydration in competitive tennis. Int J Sport Physiol Perf. 2008:3;413-423. 4. Maughan RJ, Watson P, Evans GH, Broad N, Shirreffs SM. Water balance and salt losses in competitive football. Int J Sport Nutr Ex Metab. 2007:17;583-594. 5. Palmer MS,  Spriet LL. Sweat rate, salt loss, and fluid intake during an intense on-ice practice in elite Canadian male junior hockey players. Appl Physiol Nutr Metab. 2008:33;263-271. 6. Shirreffs SM, Aragon-Vargas LF, Keil M, Love TD, Phillips S.  Rehydration after exercise in the heat:A comparison of 4 commonly used drinks. Int J Sport Nutr Ex Metab.2007:17;244-258. 7. Maughan RJ, Shirreffs SM. Development of individual hydration strategies for athletes. Int J Sport Nutr Ex Metab. 2008:18;457-472. 8. Average Temperatures for Miami, FL and Nashville, TN. The Weather Channel. www.weather.com. Accessed June 15th, 2010. 9. Average Humidity for Miami, FL and Nashville, TN. National Climatic Data Center. http://ggweather.com. Accessed June 15th, 2010. 10. Nutritional information Gatorade and Gatorade Endurance.  Gatorade.  www.gatorade.com. Accessed June 18, 2010.

  Matt Poe discusses how much aerobic exercise is too much based on an interview of Dr. David Nieman,       professor of health and exercise science at Appalachian State University in Boone, North Carolina.   A Discussion on How Much “Aerobic Exercise Is Too Much” for Endurance Athletes and     Endurance Activities with a Focus on the Ultra Endurance Athlete?   By Matt Poe, MS   Matt Poe > Listen to Dr.Nieman’s interview first (Click the "play button" below the picture)!   In the interview, Dr. Nieman reports that the benefits of moderate exercise include a boost to the immune system; however, in ultra athletes (whom can sometimes perform up to 30 hours of exercise) immune function is actually decreased.  Dr. Nieman also discusses the increased stress hormones noted in this population post exercise and how that places them in an immunosuppressed state. According to his interview a mere 24 hours of increased stress hormones in the ultra athlete increases the athlete’s risk of getting sick to six times that of normal.  Dr. Nieman suggests that a variable heart rate over shorter periods of exercise which boosts the immune function is much more beneficial than high intensity unrelenting exercise (> 90 mins) which suppresses immune function. The following summarizes the research found to support Dr. Nieman’s remarks in the interview.  In his research, Dr. Nieman suggests that immunonutrition is much needed for the ultra athlete.  In fact he states that the ultimate goal is to provide these athletes with a “cocktail” of supplements that would restore and minimize the damage of exercise induced stress and inflammation. (1) Acute cardiac dysfunction has been noted in participants of ultra endurance exercise via electrocardiographic abnormalities.  This is believed to be due to increased levels of oxidative stress, which is also associated with the development of atherosclerosis, increased risk of cardiovascular disease, and mortality. (2) Yet another factor in endurance athletes maintaining good immune function is a well balanced diet.  Exercising in a carbohydrate depleted state increases stress hormones; thus, sustained intensive exercise gives rise to increased cortisol and immunosuppresion. (3)  Including carbohydrates in a beverage also affects the rate of water assimilation and can also act to supplement reserves for muscles during ultra-endurance activities.  The fluid balance is critical in recovery from exercise, and insufficient intake during exercise causes the rate of restoration to take longer.  Diets high in protein and fat increase urinary water loss as well (4).  Discussed throughout the research of ultra endurance athletes is the incidence of hyponatremia.  It is believed to be a common finding amongst ultra endurance athletes; however, it is asymptomatic. (5) Ultra endurance exercise by most definitions is exercise greater than three hours.  After reviewing the research and postulating an educated hypothesis, I must agree with many of the previous posts regarding “how much is too much?”  I agree that when exercise becomes detrimental to health as opposed to being beneficial then the line has been crossed.  I must add  one caveat to my hypothesis and that is too much exercise is when the body is unable to sufficiently recover at rest to overcome the detrimental effects.  Only THEN is the amount of exercise being performed “too much”.   References 1.      Nieman DC. Immunonutrition support for athletes. Nutr Rev. 66:310-320, 2008. 2.      Knez WL, Coombes JS, and Jenkins DG. Ultra-endurance exercise and oxidative damage: implications for cardiovascular health. Sports Med. 36:429-441, 2006. 3.      Gleeson M, Nieman DC, and Pedersen BK. Exercise, nutrition and immune function. J Sport Sci. 22:115-125, 2004. 4.      Rehrer NJ. Fluid and electrolyte balance in ultra-endurance sport. Sports Med. 31:701-715, 2001. 5.      Weir E. Ultra-endurance exercise and hyponatremia. Can Med Assn J. 163:439, 2000.

Matt Poe discusses the safety and effectiveness, if any, by using caffeine as a stimulant. An Objective Discussion on the Use Of Caffeine By Matt Poe, MS Matt Poe > Let’s pose two questions for this discussion! PART 1: is there any neural benefit (improved alertness, improved neuromuscular recruitment, etc) for an individual to ingest moderate amounts of caffeine prior to and/or during their activities? (consider moderate to be 300 mg or less)   In a study that assessed recreationally active individuals participating aerobic-dance bench stepping, it was determined that neither 3mg/kg of body weight or 6 mg/kg of body weight had any effect on HR, VO2, VCO2, minute ventilation, RER, RPE, or REE. (1)  The effects of caffeine intake combined with casual exercise for fitness and weight management showed an increase in energy expenditure (REE) with moderate amounts being ingested. (2) Another study examined the physiological effects of caffeine on healthy subjects participating in maximal cycling bouts.  It was also determined that caffeine had no significant effect on HR, RPE, peak power, and work output.  In the same study it was suggested that not only does caffeine show no real ergogenic benefits but may even be detrimental to anaerobic performance. (3)  The study cited a slower time to reach peak power in a second exercise bout following a rest period after the first bout. Increased testosterone along with a concurrent increase in cortisol was observed in professional rugby players. (4) The anabolic effects of the increased bioavailabilty of testosterone may be negated by the increase in cortisol levels as well. PART 2: for the healthy non athlete are there any risk factors for consuming moderate levels of caffeine daily (moderate = 300 mg per day or less). Much of the research suggests that little to no side effects or risk factors that should be considered regarding ingestion of caffeine and the effects of exercise.  There is research that warns against potential side effects such as significantly higher blood lactate and significantly slower time to peak power.  In the same study one subject experienced hand tremors, feelings of hyperactivity and restlessness.  Another experienced restlessness, agitation, dizziness, and nausea. (3)  No ill effects on the body fluid balance were observed with moderate ingestion of caffeine after exercise heat exposure. (5) Some other potential side effects observed were gastric upset, withdrawal, sleep disturbance, and possible interactions with other dietary supplements. (6) Caffeine intake has been shown to promote calcium loss, thus increasing the risk for osteoporosis.  This can be most problematic in those who replace nutrient rich beverages like juice and milk with caffeinated beverages. (6)  Caffeine intake has also been shown to reduce fertility in women.  Active females often have menstrual dysfunction which may be exacerbated by high caffeine intake. In the same article it was suggested that caffeine interferes with insulin action which may affect those with poor insulin sensitivity, diabetics, or the recreational athlete. (7) Modest amount of caffeine appear to have no significant effect on heart rate variability(HRV) in young, healthy subjects. (8)  This is significant because HRV has become an important risk factor in cardiovascular events (MI, CVA, etc).   References 1.      Ahrens JN, Lloyd LK, Crixell SH, and Walker JL. The effects of caffeine in women during aerobic-dance bench stepping. Int J Sport Nutr Exer Metab. 17:27-34, 2007. 2.      Ahrens JN, Crixell SH, Lloyd LK, and Walker JL.  The physiological effects of caffeine in women during treadmill walking. J Strength Cond Res. 21:164-168, 2007. 3.      Crowe MJ, Leicht AS, and Spinks WL. Physiological and cognitive responses to caffeine during repeated, high intensity exercise. Int J Sport Nutr Exer Metab. 16:528-544, 2006. 4.      Beaven CM, Hopkins WG, Hansen KT, Wood MR, Cronin JB, and Lowe TE. Dose effect of caffeine on testosterone and cortisol responses to resistance exercise. Int J Sport Nutr Exer Metab. 18:131-141, 2008. 5.      Dias JC, Roti MW, Pumerantz AC, Watson G, Judelson DA, Casa DJ, and Armstrong LE. Rehydration after exercise dehydration in heat: effects of caffeine intake. J Sport Rehabil. 14:294-300, 2005. 6.      Tunnicliffe JM, Erdman KA, Reimer RA, Lun V, and Shearer J. Consumption of dietary caffeine and coffee in physically active populations:physiological interactions. Appl Physiol Nutr Metab. 33:1301-1310, 2008. 7.      Graham TE. Caffeine, coffee, and ephedrine: impact on exercise performance and metabolism. Can J Appl Physiol. 26:S103-S119, 2001. 8.      Rauh R, Burkert M, Siepmann M, and Mueck-Weymann M. Acute effects of caffeine on heart rate variability in habitual caffeine consumers. Clin Physiol Funct Imaging. 26:163-166, 2006.