Hll \ \ | ‘ ‘ ‘\ ‘ ‘ ‘ x ‘1‘ H ‘! .3 ‘H o ,| N \ LINEAR)! Michigan State University THE EFFECTS OF SELECTED DIETARY REGIMENS AND SODIUM BICARBONATE INGESTION UPON ACID-BASE STATUS AND PERFORMANCE CAPACITY IN AN EXHAUSTIVE RUN OF SHORT DURATION BY Kazem Boosharya A THESIS Submitted to Michigan State University in partial fulfillment of the requirements for the degree of MASTER OF ARTS Department of Health, Physical Education and Recreation June, 1978 ABSTRACT THE EFFECTS OF SELECTED DIETARY REGIMENS AND SODIUM BICARBONATE INGESTION UPON ACID-BASE STATUS AND PERFORMANCE CAPACITY IN AN EXHAUSTIVE RUN OF SHORT DURATION By Kazem Boosharya The effects of pre-exercise alkalosis induced under two diet conditions (high carbohydrate and high fat- protein), upon acid-base balance and performance capacity in exhaustive work of short duration were studied in healthy males, 21 - 26 years of age. Supplements con- sisted of 0.12 grams sodium bicarbonate per kg as the alkalizer and a placebo of 0.095 grams dextrose per kg body weight administered in a non-biasing order under both diet conditions 12 and 2 hours prior to testing on the motor driven treadmill at 9 mi/hr, 9% grade. Expired gases were collected using the Douglas method. Arterialized blood samples were taken bedore and after the run and analyzed for lactate and acid-base measure. Performance was not significantly altered pre- run pH values were significantly altered by sodium bicar- bonate ingestion and by the high carbohydrate diet. Post- run base excess or pH measures reflected no supplement or diet effects. Accepted by the faculty of the Department of Health, Physical Education and Recreation, College of Education, Michigan State University, in partial fulfillment of the requirements for the Master of Arts degree. Guidance Committee: [gm/[4 Z1.) / /o " / DEDICATION I would like to offer this work as a tribute to my lovely mother SHOKUFEH without whose affection and encouragement it would not have been possible for me to pursue further studies away from my own country and to devote myself to the task. ii AC KNOWLEDGMENTS The writer wishes to express his sincerest appreciation and infinite gratitude to his academic and thesis advisor, Professor W. D. Van Huss, for his valuable comments and constant guidance in the course of this work and my academic program at Michigan State University. Many pleasant hours were spent in association with him while this research was being conducted and while this thesis was being prepared. He contributed much of his time, wisdom and continued support to its completion. I wish also to thank the members of my guidance committee, Dr. William Heusner and Dr. Kwok Wai Ho, for their help and concerned support. The author is especially grateful to Gary Hunter for his constant help during data collection. My deep gratitude also goes to Dr. Frank Cerny, for his continued encouragement, inspiration and comments on the preliminary draft of this thesis. Finally, to all of these people and to numerous others I say "Thank you for your help and encouragement." Without them this thesis would not have been written. iii TABLE OF CONTENTS LIST OF TABLES . . . . . . . . . LIST OF FIGURES . . . . . . . . Chapter I. INTRODUCTION . . . . . . . II. III. Statement of Problem . Scope of the Study . . Significance of the Study Limitation of the Study Definition of Terms . . REVIEW OF RELATED LITERATURE . . Mechanism for Anaerobic Energy Yield Lactate Production and Removal During Exercise . . . . . Limiting Factors of Anaerobic Work Lack of Metabolic Substrates . Accumulation of Metabolic End Products Blood-Buffer Capacity Bicarbonate Infusion Hyperventilation . Summary . . . . . PROCEDURES 0 O O O O O O 0 Experimental Design . . . . Parameters of the Study . . Testing Procedure and Equipment Diet Recall . . . . . . Blood Sample . . . . . . Sodium Bicarbonate (NaHCO3) Ingestion Placement of the Electrodes . Expired Gas Collection . . . Recording the Rate of Respiration Statistical Techniques . . . . iv Page vi vii U'IUIU'Iubnh |'-' (D Chapter Page IV. RESULTS AND DISCUSSION . . . . . . . . 32 Lactic Acid Results . . . . . . . . . 32 pH Results . . . . . . . . . . . . 35 Base Excess Results . . . . . . . . . 38 Performance Times . . . . . . . . . 41 Discussion . . . . . . . . . . . . 41 V. SUMMARY, CONCLUSION, AND RECOMMENDATIONS . . 48 Summary . . . . . . . . . . . . 48 Conclusion . . . . . . . . . . . . 50 Recommendations . . . . . . . . . . 51 APPENDICES . . . . . . . . . . . . . . 52 BIBLIOGRAPHY . . . . . . . . . . . . . 59 Chapter IV. RESULTS AND DISCUSSION Lactic Acid Results pH Results . Base Excess Results Performance Times Discussion . V. SUMMARY, CONCLUSION, Summary . . . Conclusion . . . Recommendations . APPENDICES . . . . . BIBLIOGRAPHY Page 32 32 35 38 41 41 48 48 50 51 52 59 Table 2.1 4.4 4.5 4.6 4.7 LIST OF TABLES Time to exhaustion and supplement level comparisons . . . . . . . . . . . High carbohydrate diet . . . . . . . High fat x protein diet . . . . . . . Summary of food intake of an individual subject 0 O O I O O O O O O O 0 Percent of carbohydrate, fat and protein in the controlled diets . . . . . . . . Mean and standard deviation of lactic acidl (before maximal work) in mM/L . . . . . Mean and standard deviation of lactic acid3 (after maximal work) in mM/L . . . . . Change in lactic acid during maximal work of short duration . . . . . . . . . . Mean and standard deviation of pH (before maximal work of short duration) 1* pH unit . Mean and standard deviation of pH3 (after maximal work of short duration) in pH unit . Change in pH during maximal work of short duration 0 I O O O O O O O O O 0 Mean and standard deviation of BEl (before maximal work of short duration) in mEq/L . Mean and standard deviation of BE3 (after maximal work of short duration) in mEq/L . Change in base excess during maximal work of short duration . . . . . . . . . Mean and standard deviation of performance time of maximal work of short duration . . vi Page 16 23 24 26 27 33 33 33 35 35 35 38 38 38 42 Table A-1 Page Percent dietary constituent (CHO, fat, protein) in diet, and indicates that the dietary manipu- lation did significantly alter the intake of CHO and fat and proteins . . . . . . . 54 Statistical Analysis - . . . . . . . . 57 Statistical Analysis . . . . . . . . . 58 vii LIST OF FIGURES Figure Page 3.1 Single Bipolar V5 Configuration . . . . . 30 4.1 Lactic Acid Results . . . . . . . . . 34 4.2 pH Results . . . . . . . . . . . . 37 4.3 Base Excess Results . . . . . . . . . 40 4.4 Performance Times . . . . . . . . . 43 A-l Change of food intake in the different experimental conditions . . . . . . . 55 viii CHAPTER I INTRODUCTION Maximal anaerobic work lasting greater than thirty seconds usually results in a large uncompensated acidosis (5, 32, 55, 57). The accumulation of lactic acid inside the muscle cell lowers the intracellular pH (32, 35). Minor changes from the normal pH value have been shown to produce alterations in the rates of chemical reaction in the cell (2, 3, 17, 27, 32, 43). It also became evident that these modifications are quantitatively different with exercise of different durations and intensities. Like- wise the humoral response to muscular work might be quite different in trained and untrained organisms. The changes of the body fluids during and after severe exercise may be related in two aspects: the physico-chemical alterations which directly or indirectly affect the performance capacity or the loss of certain compounds (i.e., K, Mg, Na) from the active tissues leading to a depletion of these compounds or both (1, 24, 36, 41, 62, 68). Although this will eventually impair the capacity of performance, many points still remain obscure and further biochemical studies are needed. The assumption that the metabolic accumulation and its resultant shift in pH is the limiting factor of anaerobic performance time has been supported by several findings (11, 32, 42, 55). The formation of lactic acid in response to electrical stimulation of the muscle stopped when the intracellular pH dropped from 6.98 units (average resting value) to about 6.3 (32, 34). Also, when the pH in the muscle cell lowered to less than 6.3, an inhibition of glycolysis has been observed (34, 35). The activity of the key glycolysis enzyme phosphofructokinase (PFK) is reduced with increasing hydrogen ion concentration (71, 73). Decreased blood pH values impair neuromuscular con- duction of a stimulus (20) and the ability of calcium ions to bind to the contractile protein in the myofibrils is diminished (27, 43). The extent of metabolic acidosis after maximal exercise was in fifty healthy males. Lactate values as high as 12.67 mEq/L along with corresponding low pH values of 7.19 were reported. The values for standard bicarbonate (SB) and base excess (BB) were 14.2 mEq/L and -l4.4 mEq/L respectively. These measurements indicate severe exercise acidemia (11). From these findings, it appears that the decrease in pH due to lactate accumulation could be a limiting factor in high intensity work of short duration. An increase, therefore, in the buffer capacity of the blood has been proposed as a procedure which may reduce the acidosis and delay the onset of fatigue (21, 22, 39, 68, 69). Coaches and physical educators have been searching for food substances which increase buffer capacity of the blood and result in improved performance in competition. Blood alkalizers (e.g., sodium bicarbonate, sodium citrate and potassium citrate) and carbohydrates have been proposed as aids to anaerobic and aerobic work capacity. Improvements in performance have been observed in swimmers and runners who had previously ingested sodium bicarbonate (21, 22, 39, 68, 69). Dennig (21, 22) reported that acidification achieved via ammonium chloride ingestion prior to endurance running induced earlier onset of exhaustion whereas alkalizing of the body before prolonged exercise (running or bicycle ergometer) extended per- formance by 30 to 100 percent and reduced the time necessary for recovery after exhaustion (22). To gain additional insight into these phenomena during intensive muscular exertion the effects of orally ingested sodium bicarbonate accompanied with high carbohydrate or high fat—protein were selected as the subjects of investigation in this study. Statement of Problem To determine the effects of diet (high carbo- hydrate and high fat-protein) and sodium bicarbonate ingestion upon acid-base status and performance capacity in an exhaustive run of short duration. The problem can be further delineated as an attempt to evaluate: a. The effects of sodium bicarbonate ingestion upon acid-base status and performance time in healthy young college age men under high carbohydrate and high fat-protein dietary conditions. b. The effects of high carbohydrate and high fat-protein dietary conditions upon the acid- base status and performance time in healthy young college age men. Scope of the Study The study utilized seven healthy college males with no specific fitness who varied their diets from 19.14% to 59.6% carbohydrate and from 24.6% to 49.5% fat, respectively. Only a .12 g/kg dosage of sodium bicarbonate was evaluated under the various conditions. Significance of the Study The study should add information concerning the acid-base parameters, diets, and oxygen debt relations in exhaustive work of short duration. Limitation of the Study The study was limited to college age men, a single bicarbonate supplement level and to diet levels of 19.14% to 59.6% CH0 and 24.6% to 49.5% fat. Due to psychological factors, in any maximal test, there is always a question as to whether the subject is actually exhausted. The amount of food, rest, tobacco that the subject had before testing could not be con- trolled. Definition of Terms Maximal or Exhaustive Exercise. The time at which the individual is unable to continue work at the desig- nated load. Glycolysis. The anaerobic breakdown of one molecule of glucose to two molecules of pyruvic acid. Anaerobic Reaction. A metabolic or chemical reaction that can take place without the utilization of oxygen. Lactic Acid. An organic acid, the end product of anaerobic metabolism of glucose. Agid. An acid is a substance that can donate a proton to another substance. Base. A base is a substance that can accept a proton from another substance. Acid-Base Balance. The ratio of H+ and OH- ions in the blood. Acid-Base Regulation. Those chemical and physical processes which maintain the hydrogen ion (H+) concentra- tion in body fluids at levels compatible with life and proper functioning, i.e., good health. (Acidn .9 H+ + base n-l). Acidosis. A condition in which there is an excess of hydrogen ions in the blood. Acidosis is usually con- sidered to be at a pH of less than 7.36. Alkalosis. A condition in which there is a reduced level of hydrogen ions in the blood. The pH is usually considered to be greater than 7.42. pH. A notation of expressing the degree of acidity or alkalinity as the negative logarithm of the hydrogen ion concentration (-log H+). The normal blood pH is 7.42. Buffer. A substance that minimizes the change in pH of a fluid when acids or alkalies are added. Maximal Physical Capacity. The maximum time an individual is able to work at a defined work load. Oxygen Uptake (V02). The volume of oxygen absorbed per minute during work. Oxygen Debt. The amount of oxygen consumed during the recovery period following work in excess of that used at rest. It has been proposed that the debt consists of two portions: alactacid and lactacid. The alactacid oxygen debt is thought to represent the oxygen required to resynthesize the creatin phosphate and adenosine triphosphate to the level of homeostasis. The lactacid oxygen debt is thought to represent the quantity of oxygen required to restore the lactic acid levels to normal levels. CHAPTER II REVIEW OF RELATED LITERATURE The relevant studies are grouped in three cate- gories for review purposes: (1) mechanisms for anaerobic energy yield, (2) limiting factors for anaerobic work, and (3) blood-buffer capacities. Mechanism for Anaerobic Energy Yield In anaerobic work (without oxygen) the energy requirement of activity is greater than the available oxygen supply. Therefore, energy must be generated from anaerobic metabolism (glycolytic pathways). The relative importance of this energy liberating process depends upon several factors, i.e., the type, intensity, and the dura- tion of the work. During heavy exercise of short duration, energy is derived from the splitting of energy-rich sub- stances, i.e., adenosine triphosphate (ATP) and creatine phosphate (CP) which are collectively known as the phospha- gens. Their average concentrations in human skeletal muscle are about 4 and 16 mmole/kg wet muscle, respectively (29, 36, 41, 42). A depletion of the ATP and CP stores in relation to the work load has been observed while the muscle 8 lactate concentrations increased faster at higher work loads concomitant with increased glycolysis. According to Margaria et al. (47, 48, 50, 51), the ATP and CP stores account for the alactacid anaerobic energy output. The anaerobic breakdown of glycogen or glucose to lactate can also supply energy to contracting muscles. Two enzymes have been suggested to have key positions in the glycolysis. One of them, phosphorylase, has been shown to be activated by the muscle contraction (5, 16, 18, 24, 56). With higher work intensities, progressively higher activities of this enzyme have been observed (5, 16). Another enzyme of glycolysis which regulates the breakdown of glucose residues is phosphofructokinase (PFK) (5, 30, 71, 73). It has been shown to be inactivated by high concentrations of ATP and activated in the anaerobic cellular state (5, 30, 71, 73). Lactate Production and Removal During Exercise The end product of glycolysis is lactic acid (34). With a progressively higher intensity of work of greater than ten seconds duration, progressively higher quantities of lactic acid are produced. Also with increased duration of high intensity work to the point of exhaustion higher lactic levels were observed (33). In work of lower intensity, removal of lactic acid during work has been observed. In seeking the explanation 10 for the increased rate of lactate removal, several factors must be considered. The importance of the liver in the elimination of lactate during exercise has been pointed out by several investigators (19, 61). In addition to the liver skeletal muscle (40) and other tissues (45, 46) are also able to remove lactate even during the course of muscular work. LimitingyFactors of Anaerobic Work The limiting factor of anaerobic work is open to speculation. The lack of metabolic substrates; the accumulation of metabolic end products; or a combination of both could provide explanations for the limits of maxi- mal work of short duration. Lack of Metabolic Substrates Hultman and Bergstrom (36) support the theory that the limiting factor of anaerobic performance is due to a lack of metabolic substrate. These authors investi- gated the levels of CP and ATP in human muscle during exhaustive work. There was a depletion in the CP concen- trations following exercise, the pre-exercise average con- centration ratio was 7.00 mmoles per 100 g dry muscle. The ATP reduction was approximately 40 percent of the initial value. Karlesson, Diamant and Saltin (41) recently confirmed the depletion of CP and lowering of ATP in exhaustive exercise. The small breakdown in ADP 11 as compared to the total breakdown of the ATP and CP stores, led the authors to conclude that the myokinase reaction was probably not of quantitative importance in the anaerobic energy yield during exercise. The increase in glycolysis during maximal exercise was attributed to the elevated glucose 6 phosphate and lactate concentrations in the muscle (5, 29). The inter- relationship between phosphagen depletion and anaerobic glycolysis was further illustrated by the relationship between the lactate concentration in the working muscle and the simultaneous depletion of the phosphagens of 4-5 mmoles per kg"1 wet muscle had to be present before the lactate concentrations increased over resting levels (41, 44). Accumulation of Metabolic End Products Many investigations (ll, 32, 42, 55) support the metabolic accumulation theory and its resultant shift in pH as the limiting factor of anaerobic performance. Bouhuys (11) investigated the extent of metabolic acidosis after maximal exercise in fifty healthy males. Lactate values as high as 12.67 mEq per liter along with corresponding low pH values of 7.19 were reported. The values for standard bicarbonate (SB) and base excess (BE) were 14.2 mEq per liter and -l4.4 mEq per liter, respectively. These measurements indicate severe 12 exercise acidemia. It was also observed that the direct chemical analysis of blood lactate was the best index of exercise acidosis. Hartley and Saltin (31) studied acid-base balance during maximal treadmill running, leading to exhaustion in 3 to 5 minutes. Low pH values of 7.21, 7.11 and 7.03 were obtained in brachial artery, brachial vein and femoral vein, respectively. The drop in pH was accom— panied by an increase of lactate to 13.1 mmoles per liter (117 mg) reflecting the exercise acidosis brought about by short, severe work bouts. Karlesson and Saltin (42) investigated the relationship between fatigue and muscle concentrations of lactate, ATP, CP and blood lactate during 2, 6 and 16 minutes of exhaustive exercise on a bicycle ergometer. The highest mean blood lactate of 13.4 mmoles per liter (120.6 mg) was obtained at the shortest maximal work load. In all work bouts the break- down of ATP and CP was already maximal at two minutes of work. However, the accumulation of lactate in the muscle and blood increased continually until exhaustion. Acid-base balance after maximal exercise of short duration was further investigated by Osnes and Hermansen (55). Fourteen young male subjects performed intermittent exercise on a treadmill. Each exercise bout led to exhaustion in 40 to 60 seconds. The experiments were preceded by a 10 minute warm-up representing approximately 13 50 to 60 percent of the individual's VO2 maximum. Blood lactate was found to increase up to 32.1 mmoles per liter (288 mg). This value is very high and inconsistent with that of other investigators (5, ll, 49). Extremely low blood pH value of 6.8 was reported indicating severe exercise acidosis. Hermansen and Osnes (32) continued the experiments in a group of 13 male and female subjects. After one maximal exercise bout leading to exhaustion in 1.66 minutes, blood pH continued to fall in the recovery period, reaching its lowest mean value of 7.11 in the fourth minute. It was suggested that a decrease in pH is not the limiting factor for maximal work. Contrary to the speculation that pH is not the limiting factor in maximal work, Craig (17) found that a decreased pH reduced the rate of glycolysis in nervous tissue and consequently the rate of ATP synthesis. Del Castillo (20) investigated the mechanism of increased acetylcholine sensitivity of skeletal muscle in low pH solution and found with pH values below 7.1 neuromuscular transmission and the reactivity of skeletal muscle to acetylcholine may be affected. Recent studies on cardiac muscle (43) and skeletal muscle (27) have provided evi- dence suggesting that increased hydrogen ion concentration may affect the myosin-actin interaction during the process of contraction by inhibiting the calcium-troponin binding 14 activity. Tibes et a1. (70) examined the electrolyte changes brought about by exercise acidosis. Their results suggest that an increase in hydrogen ion concen- tration inhibits ionic transport through the muscle cell membrane due to an accumulation of sodium within the cell. From these diverse studies, it appears that the decrease in pH due to lactate accumulation could be a limiting factor in high intensity exercise of short duration. Blood-Buffer Capacity During intensive muscular exertion, acids accumu- late in the blood which result in a large uncompensated acidosis (5, 32, 55, 57). To take care of the increased quantity of acid produced, more buffer alkalies are needed. It is logical to assume that an artificial increase in the amount of alkalies in the body should increase work capacity. Thus an increase in the buffer-capacity of the blood should reduce the acidosis and delay the onset of fatigue. Such an assumption has been responsible for the alkali feeding of athletes. Bicarbonate Infusion In early experiments [Dorow 1940, Govaerts and De Lanne 1940, referenced in (30)] an improvement in per- formance was observed in swimmers and runners who ingested sodium bicarbonate. Dennig and co-workers (21, 22) found an increase in endurance after alkali intake. They 15 recommended using sodium citrate, 5 gm; sodium bicarbonate, 3.5 gm; and potassium citrate, 1.5 gm. A daily dose taken after a meal for two days before a test and two days after the test was used to avoid an acidotic reaction. The experiments were based on tread- mill and stationary bicycle tests. Staib [referenced in (30)] obtained comparable results, as well as a much lesser reduction in blood pH, standard bicarbonate and base excess in swimming mice after administration of either sodium bicarbonate or tris-hydroxy-methol-aminomethane (Tromethamine). Similar experiments were conducted by Simmons and Hordt (68) at the University of Wyoming with eight trained swimmers (five sprinters and three distance swimmers). They were in a highly trained state, having just completed the water polo season. Alkali compounds (.715 grams sodium citrate, 0.50 grams sodium bicarbonate and 0.215 grams potassium citrate) were administered to the experi- mental groups, and placebo to the control groups, begin- ning two days prior to each test. The results of this study indicate that the administration of supplemental alkali produced significant improvements in the perform- ances of trained sprint swimmers (Table 2.1). The improve- ment, however, was slight when compared to the results reported by the other investigators (Table 2.1). In this investigation the trained swimmers excreted significantly .ncuan no: maze Amoumuv onmomam mumconumo Eswoamo ommbn .onwomam Madam ca venom 16 om.m mo.o vm.~ m~.~ com. ow.m mH.o av.~ m~.m oma. oo.HH mN.o Hm.~ wN.N mwo. mfihmv Hmucfim om.Hm wm.o Ho.m hv.m ma. name Eonumuud oo.oHH oo.- oo.~e oo.o~ ma. omimmv mflccmo om.mm mm.~ em.m mm.m om. nAmov couusm om.mm om.m om.h om.e om. nAmmv meson mmmmmmm ma.m mo. Hm. em. NH. wAmov .am no mcoesfim a mmmmnocH mmocmHOMMHo ucmamammsm oncomam Aux\8mv amoum w Hm>mq AcwEv cowumsmnxm on made ucmamammsm .chmHHmmEoo Hm>ma usmfimammsm can cowumsmnxw on mEHBII.H.N mamma 17 less alkali than untrained subjects during the five hour period following alkali administration, i.e., from 23.7 to 28.7 mmoles and from 22.4 to 39.0 mmoles, respectively (68). The effects of alkalosis on performance and lac- tate formation during exhaustive exercise in man was investigated by Atterbom (9). Seven male volunteers were tested following ingestion of 25 mEq or 0.18 grams of NaHCO per kg body weight to see the effect of sodium 3 bicarbonate ingestion on adaptation to and recovery from brief maximal activity. Although the reported results show a 21.9 percent increase in time to exhaustion, the mean difference of 0.54 minute in exercise time was not statistically significant (Table 2.1). The BB decrement was larger (from +5.8 to -11.8 mEq/L); despite decreased H+ ion concentration from 67.6 to 59.6 nanomoles per liter (nM/L). The acidotic stresses were lessened by the pre-exercise metabolic alkalosis. The increased fixed acid production has been shown to reflect greater anaerobic capacities (9, 10). Margaria (47) observed that the ingestion of 2.43 grams mixture of sodium and potassium citrate had no significant effects either on exhaustive exercise or in the evolution of lactate production. Only after massive doses of NaHCO (i.e., 12 grams) did the time to exhaustion 3 increase (up to 5.8 percent). This difference was not 18 statistically significant. Dill, et a1. (23) found that an intake of sodium bicarbonate allowed a greater oxygen debt but they could not notice any significant differences in muscular performance. Recently, Poulus et a1. (57) studied acid-base balance and subjective feelings of fatigue during exercise. Sodium bicarbonate infusion was effective in correcting the exercise acidemia but had no effect on the subjective feel- ings of fatigue. It was suggested that the acid-base state of arterial blood was not one of the mechanisms underlying the feelings of fatigue. The authors did indicate that the infusions might have an effect, if H+ ion concentra- tion increased to values found by Hermansen and Osnes (32) and Osnes and Hermansen (55). Hyperventilation A transient increase in the buffer capacity of the blood can be produced by hyperventilation. However, this consideration and its possible effects on performance have been overlooked in the literature. The experiments thus far have been primarily centered on alterations in circu- latory parameters during hyperventilation. Clark (14) reported a two-fold increase in blood flow to the forearm during moderate overventilation. It was suggested that a falling CO tension stimulated some unidentified chemo- 2 receptor mechanism causing muscular dilation. Richardson l9 and Wassermann (58) supported the previous findings by reporting a 20 percent increase in blood flow through the forearm due to hypocapnia induced by voluntary hyper- ventilation. Richardson and Kontos (59) found that hypo- capnic alkalosis induced by hyperventilation in normal man was associated with increased cardiac output and heart rate and decreased mean arterial blood pressure and systemic vascular resistance. These were reported to be most pronounced one minute following the onset of hyper- ventilation. All the experiments were conducted in the resting state. Contrary to these findings, Betz (10) in a thoroughly documented review of cerebral blood flow indicated that a decrease in PCO due to hyperventilation 2 caused vasoconstriction. This response resulted in a decrease of cerebral blood flow, possibly affecting the regulatory mechanisms of the brain. Summary Anaerobic work is activity in which the oxygen supply does not meet the oxygen demands of the tissue. Energy must be supplied from the phosphagens and glycolysis. Anaerobic work may be limited by the lack of metabolic substrate; the accumulation of metabolic end products or a combination of both. It has been demonstrated that high intensity sport competition and severe exercise results in a large 20 uncompensated acidosis which may have a detrimental effect on time to exhaustion. A transient increase in the blood buffer capacity may reduce or delay acidosis. Thus, the duration of an anaerobic run may be prolonged. Temporary alkalosis can be created by sodium bicarbonate infusion or hyperventilation. There is evidence in the literature that alkaline ingestion delays the onset of fatigue during anaerobic running. CHAPTER III PROCEDURES The purpose of this experiment was to determine the effects of sodium bicarbonate (NaHCO3) ingestion in conjunction with two levels of diets [i.e., high carbo- hydrate (CH0) and high fat-protein] upon acid-base balance and performance in exhaustive work of short duration. Experimental Design Seven healthy college male volunteers (age 21-26 years) were used as subjects and were randomly assigned into the four following experimental conditions: high CHO plus placebo high CHO plus NaHCO3 high fat-protein plus placebo high fat-protein plus NaHCO3 and all subjects were tested under the four experimental conditions. They were all tested once a week between 0900 and 1600 hours. The temperature and humidity were approxi- mately constant (72°F and 48% RH) while the subjects were tested. 21 22 Diet Conditions High fat-protein High carbohydrate ‘é’ a :g placebo 8 H S g sodium r4 bicarbonate 8: a The subjects were assigned randomly to the two regulated diets, two days prior to testing on the tread- mill. The test runs were performed on the motor-driven treadmill at a speed of nine miles per hour at an incline of nine percent grade. Each subject ran to exhaustion, that is, as fast as and as long as possible and their performance times were recorded. The foods recommended in the high carbohydrate and high fat-protein dietary regimens are listed in Tables 3.1 and 3.2. They were sub- jected to each dietary condition twice in which they received NaHCO3 or placebo as follows: a. 0.12 gram of sodium bicarbonate (NaHCO3) per kilogram (kg) of body weight. b. 0.095 gram of dextrose (placebo) for kg of body weight. 23 TABLE 3.l.--High carbohydrate diet. DIET: HIGH CARBOHYDRATE Foods that can be consumed in any amounts: Fruit (except cranberries, plums, prunes) Vegetable (except corn and lentils) Bread Cereal Potatoes, Rice, Macaroni Margarine Sugar Skim Milk (no more than 3 servings of whole milk) Cottage Cheese Lettuce Pancakes No more than one serving of any combination of the following can be consumed each day: Meat E99 Fish Nuts (including peanut butter) Corn, Lentils Cranberries, Plums, Prunes Cakes and cookies, plain Butter AN EFFORT MUST BE MADE TO KEEP YOUR TOTAL CALORIC INTAKE RELATIVELY CONSTANT. A BODY WEIGHT LOSS OR GAIN DURING THE CONTROLLED DIET PERIOD COULD EFFECT THE EXPERIMENTAL RESULTS. 24 TABLE 3.2.-—High fat x protein diet. DIET: HIGH FAT X PROTEIN Foods that can be consumed in any amounts: Meat Fish Fowl Eggs Nuts Peanut Butter Bacon Butter Corn Lentils Cranberries Lettuce Margarine AT LEAST 3 SERVINGS OF ANY COMBINATION OF MEAT, FISH, AND FOWL MUST BE CONSUMED EACH DAY. No more than 3 servings of any combination of the follow- ing canfbe consumed eacH day: Fruit Vegetables Bread Cereal Potatoes, Rice, Macaroni Margarine Sugar Milk Cakes and cookies, plain Pancakes AN EFFORT MUST BE MADE TO KEEP YOUR TOTAL CALORIC INTAKE RELATIVELY CONSTANT. A BDY WEIGHT LOSS OR GAIN DURING THE CONTROLLED DIET PERIOD COULD EFFECT THE EXPERIMENTAL RESULTS. 25 Parameters of the Study The following parameters have been selected for study: (a) performance time, (b) lactic acid--before work, (c) lactic acid--after work, (d) change in lactic acid, (e) pH--before work, (f) pH--after work, (9) change in pH, (h) base excess--before work, (i) base excess-- after work, and (j) change in base excess. Testing Procedure and Equipment After the individual's arrival in the laboratory the tasks listed were completed in the order which follows. 1. Diet recall. 2. Blood samples taken. 3. Sodium bicarbonate (NaHCOB) ingestion. 4. Placement of electrodes on subject's chest. 5. Expired gas collection. 6. Recording heart rate (HR) during both, run and recovery. 7. Recording of the rate of respiration. More specific details for each aspect of the testing protocol is prsented in the subsequent sections. Diet Recall The subject recorded the amount and type of food stuffs as outlines on the form shown in Table 3.3. The number of calories and the carbohydrate, fat and protein 26 Namath: nonumo Em .v>¢ Hmuoa mwwuonU susam .cuoumom can .mwflooo: .oowu caman .wcouaouE .«uuunmunm mouaaocuu :wOuOum unm .m>< Em Em Annoy m m m e z e 2 xmn hon mmCA>Hmm mo umafisz .u: xom out \\ \ mama uomnnzm Bomnmam AHQZH Zd ho N¥fiucw no mo mxuucw ween mo >H~EE9mul.m.m mammc cumocmum can cmw:nl.oa.v mqmda Performance Time (880.) 43 I High fat-protein High carbohydrate IT: § 25:: § 1;: \\\ \\\\ a": .\\\\\V .\\\\\‘ Placebo NaHCO; Fig. 4.4. Performance Times 44 reflect a metabolic acidosis in the blood indicated by a lowering of blood pH from 7.44 to 7.18 pH units (Table 4.6) and a decrease in base excess from -.94 to -l7.5 mEq/L (Table 4.10). The obtained values indicate that base excess tends to reflect changes in acid base status of the blood, and suggest that estimation of BE can be used for the assessment of exercise acidosis. Quantitative relations between pH and BE on one hand and blood lactate content on the other hand are complex. However, pH is affected not only by metabolic acidemia (pH < 7.35 or alkalemia pH > 7.45) but also by respiratory acid base changes, which occur during and shortly after exercise (11, 20, 54). The findings of this study do not strengthen the hypothesis that pre- exercise alkalinization has a significant effect on per- formance time. The claim that NaHCO3 increased physical work capacity (21, 24, 39, 68, 69) has been denied by Margaria et a1. (49) and Johnson (38). It has even been suggested that endurance may be reduced by pre-exercise alkalosis (49). If no increase in performance time followed pre-exercise metabolic alkalosis or increased buffering capacity, the question arises as to the nature of the limiting factors in maximal work of short duration. In this case three factors appear possible. The validation of each of these would require further study involving integration of biochemical assays with extra- and 45 intracellular examinations of electrolytes and pH. These .factors are: 1. Intracellular accumulation of lactate and pyruvate levels which would halt anaerobic glycolysis. 2. Decrease in intracellular pH to a level less conducive to enzymatic activity and muscle contraction. 3. Intracellular depletion of those cations which are necessary for neuromuscular func- tion, i.e., Mg++, Ca++ and K+. Intracellular accumulation of lactic acid has commonly been shown to be increased in blood lactic con- centrations beyond ten mEq/L (21, 22); 135 to 175 mg per 100 ml of blood (4, 5) has been proposed to constitute the limits for continued effort. In the present study, under all conditions, these levels were approached, sup- porting the concept that lactate levels this high may limit performance. It is believed that the acidity of muscle cells appears to be influenced by extracellular loads at HCOE (2). In addition at all degrees of extracellular meta- bolic alkalosis the cellular H+ ion concentration varies linearly with extracellular H+ ion levels (3). One to two hours, however, is required for equilibrium to be attained between extracellular HCOS ion elevated by 46 intravenous infusion of NaHCO and total body water (12, 3 72). Consequently it appears that regardless of extra- 3 intracellular [H+]. cellular HCO levels, extracellular pH should reflect the It may be speculated that the work limiting changes in heavy muscular work may have also occurred among the electrolytes necessary for neuromuscular func— tion. Plasma K+ ion concentration has been shown to increase approximately thirty percent immediately follow- ing strenuous exercise (26). Hyperkalemia following severe exercise has been verified (60) as has measured urinary excretion of K+ ions (62). That electrolyte levels change, is also supported by Mudge et a1. (53) who found serum potassium varied from 3.9 to 4.8 mEq/L for the controls, from 2.5 to 3.7 mEq/L for an acidity group and from 1.8 to 2.7 mEq/L for an alkalotic group. Thus, the values of lactic acid and pH in this study do not seem to provide sufficient evidence for them to be regarded as the limiting factors of performance during maximal work of short duration. The change in base excess, however, is clearly related to performance times. Although the present study does not add much new information concerning limiting factors in performance it does add new data concerning optimal pH levels for performance and base excess changes most closely related to performance. The state of alkalinity does not seem to 47 be related to performance and to greatest base excess changes. It seems as if there is an optimal level around a pH of 7.4 to 7.5 but if it is more alkaline (> 7.5) or more acid (< 7.4) that performance and base excess change is negatively affected. Thus bicarbonate ingestion would appear to be beneficial in the more acid producing high fat-protein diet condition but detrimental in the more alkaline producing high carbohydrate diet condition where the pH reached 7.6. These data are con- sistent with those of Hunter (37) and support that the high pH may have a depressing effect on phsophofructo- kinase activity (71, 73). On the basis of these results a rationale is evident for some investigators observing increases in performance following bicarbonate ingestion and others observing decreases. In this investigation it is interesting to note that the body weight was significantly affected by the dietary alteration and by the interaction of diet by supplement at .10 level (Appendix Table B-l). CHAPTER V SUMMARY, CONCLUSION, AND RECOMMENDATIONS Summary The purpose of this investigation was to determine the effects of high carbohydrate and high fat-protein diets and sodium bicarbonate ingestion upon the acid base status and performance capacity in an exhaustive run of short duration. A review of the literature is suggestive that a transient increase in the blood buffer capacity may reduce or delay acidosis, thus, the duration of an anaerobic run may be prolonged. Improvements in performance have been observed in swimmers and runners who had previously ingested sodium bicarbonate (21, 22, 39, 68, 69). A few studies suggest that the pre-exercise sodium bicarbonate ingestion had no significant effects an exhaustive run (23, 47, 57). Thus, in this investigation the effects of alteration of the diet and supplement to provide pre- exercise metabolic alkalosis in anaerobic work, seven healthy college age men volunteers (21-26 years) were tested. Sodium bicarbonate and the placebo (dextrose) were given in gelatin capsules, .12 and .095 gram per 48 49 kilogram of body weight, respectively. The test runs were performed on the motor driven treadmill at a speed of nine miles per hour and an inclination of nine percent grade. The work bouts on the treadmill was performed four times by each subject under four diet conditions. The testing was done in both morning and afternoon between 0900 and 1600 hours. The following results were obtained: 1. The differences in lactic acid production attributable to dietary alterations were small and almost negligible. However, as expected, the before run- after run differences in lactic acid were significantly different. 2. Changes in pH due to sodium bicarbonate ingestion were not significantly different. Pre-run pH values when accompanied by the high carbohydrate diet were significantly higher--above 7.46. 3. In the post-run base excess measures no supplement or diet effects were evident. However, a significant diet by supplement interaction was observed. The greatest changes were observed under the high fat- protein diet with NaHCO supplementation and under the 3 high carbohydrate—placebo condition. Although a signifi— cant diet effect was observed in the change in base excess, the significance was due primarily to the high 50 carbohydrate-placebo differences rather than the high carbohydrate-NaHCO changes. 3 4. A four percent increase in performance time was observed following pre-exercise alkalinization. This increase was not statistically significant. Conclusion The following conclusions seem justified on the basis of the statistical analysis of presented data: 1. The dietary intake of the subjects, i.e., carbohydrate, fat and protein were altered significantly by the controlled diet. 2. Sodium bicarbonate supplementation did not alter maximal work performance of short duration. 3. The greatest changes in base excess were observed under the high fat—protein diet with bicarbonate supplementation and under the high carbohydrate diet with no bicarbonate ingestion. 4. It appears that performance may be negatively affected when the pH exceeds 7.45 as observed under the high carbohydrate-bicarbonate supplement condition. 5. The alteration of dietary intake had a significant influence on body weight. 51 Recommendations The following set of recommendations are pre- sented in the hope that further research be conducted along these lines: 1. Since sodium bicarbonate ingestion increases blood pressure by means of vasoconstriction of blood vessels, the presence of a physician as a supervisor is strongly suggested to protect the subjects from any damages which may take place while the work test is accomplished. 2. Large, more random sample size would enable definite conclusions as to the statistical significance of the findings. 3. There must be some kind of control on food intake (amount and type), relaxing, physical activity, and the use of tobacco or alcohol prior to testing. 4. The amount of bicarbonate excreted into urine before and after exercise would add additional information. 5. This investigation was conducted on the assumption that pre—exercise alkalosis metabolic may delay the mechanism of fatigue. The role of sodium bicarbonate ingestion on compensation of depleted cation and thereby on performance time should be further examined in terms of the biochemical and physical determinants of each. 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E 88 ugh? uhwwawmd 3.... sea 05.288 3% 58””qu 3% Scum-3.13m Pasqug>mxvadasacc sxauanuxvaaemaahwea chasm .ueuaeoc4 sensuaaucum .Nlm manta. xHozmmm< BIBLIOGRAPHY 59 lo. BIBLIOGRAPHY Agersborg, Jr., H. P. K., and Shaw, Jr., D. L., "Physiologic approach to the problem of fatigue." J. Sp. Med. Phys. Fit. 2:217, 1962. Adler, S., Roy, A., and Relman, A. S., "Intra- cellular acid-base regulation. The response of muscle cells to changes in C02 tension or extra- cellular bicarbonate concentration." J. Clin. Invest. 44:8, 1965. Adler, S., Roy, A., and Relman, A. 8., "Metabolic control of cell pH." J. Clin. Invest. 43:1251, 1964. Astrand, I., Astrand, P. 0., Christensen, H., and Hedman, R., "Circulatory and respiratory adapta- tion to severe muscular work." Acta. Physiol. Scand. 50:254, 1960 Astrand, P. O., and Rodhal, K., Textbook of Work Physiology. McGraw-Hill Book Company, N.Y., 1970. Astrand, P. 0., and Saltin, B., "Oxygen uptake during the first minutes of heavy muscular exercise." J. 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