Effect of glutamine supplementation combined with resistance training in young adults.
Candow DG, Chilibeck PD, Burke DG, Davison KS, Smith-Palmer T.
College of Kinesiology, University of Saskatchewan, Saskatoon, Canada.
The purpose of this study was to assess the effect of oral glutamine supplementation combined with resistance training in young adults. A group of 31 subjects, aged 18-24 years, were randomly allocated to groups (double blind) to receive either glutamine (0.9 g x kg lean tissue mass(-1) x day(-1); n = 17) or a placebo (0.9 g maltodextrin x kg lean tissue mass(-1) x day(-1); n = 14 during 6 weeks of total body resistance training. Exercises were performed for four to five sets of 6-12 repetitions at intensities ranging from 60% to 90% 1 repetition maximum (1 RM). Before and after training, measurements were taken of 1 RM squat and bench press strength, peak knee extension torque (using an isokinetic dynamometer), lean tissue mass (dual energy X-ray absorptiometry) and muscle protein degradation (urinary 3-methylhistidine by high performance liquid chromatography). Repeated measures ANOVA showed that strength, torque, lean tissue mass and 3-methylhistidine increased with training (P < 0.05), with no significant difference between groups. Both groups increased their 1 RM squat by approximately 30% and 1 RM bench press by approximately 14%. The glutamine group showed increases of 6% for knee extension torque, 2% for lean tissue mass and 41% for urinary levels of 3-methylhistidine. The placebo group increased knee extension torque by 5%, lean tissue mass by 1.7% and 3-methylhistidine by 56%. We conclude that glutamine supplementation during resistance training has no significant effect on muscle performance, body composition or muscle protein degradation in young healthy adults.
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J Strength Cond Res 2002 Feb;16(1):157-60
The effects of high-dose glutamine ingestion on weightlifting performance
Antonio J, Sanders MS, Kalman D, Woodgate D, Street C.
Sports Science Laboratory, University of Delaware, Newark, Delaware 19716, USA.
The purpose of this study was to determine if high-dose glutamine ingestion affected weightlifting performance. In a double-blind, placebo-controlled, crossover study, 6 resistance-trained men (mean +/- SE: age, 21.5 +/- 0.3 years; weight, 76.5 +/- 2.8 kg(-1)) performed weightlifting exercises after the ingestion of glutamine or glycine (0.3 g x kg(-1)) mixed with calorie-free fruit juice or placebo (calorie-free fruit juice only). Each subject underwent each of the 3 treatments in a randomized order. One hour after ingestion, subjects performed 4 total sets of exercise to momentary muscular failure (2 sets of leg presses at 200% of body weight, 2 sets of bench presses at 100% of body weight). There were no differences in the average number of maximal repetitions performed in the leg press or bench press exercises among the 3 groups. [/b]These data indicate that the short-term ingestion of glutamine does not enhance weightlifting performance in resistance-trained men.[/b]
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Int J Sports Med 2000 Jan;21(1):25-30 Related Articles, Links
The effect of free glutamine and peptide ingestion on the rate of muscle glycogen resynthesis in man.
van Hall G, Saris WH, van de Schoor PA, Wagenmakers AJ.
Department of Human Biology, Maastricht University, The Netherlands.
RH01769@RH.DK
The present study investigated previous claims that ingestion of glutamine and of protein-carbohydrate mixtures may increase the rate of glycogen resynthesis following intense exercise. Eight trained subjects were studied during 3 h of recovery while consuming one of four drinks in random order. Drinks were ingested in three 500 ml boluses, immediately after exercise and then after 1 and 2 h of recovery. Each bolus of the control drink contained 0.8 g x kg(-1) body weight of glucose. The other drinks contained the same amount of glucose and 0.3 g x kg(-1) body weight of 1) glutamine, 2) a wheat hydrolysate (26% glutamine) and 3) a whey hydrolysate (6.6% glutamine). Plasma glutamine, decreased by approximately 20% during recovery with ingestion of the control drink, no changes with ingestion of the protein hydrolysates drinks, and a 2-fold increase with ingestion of the free glutamine drinks. The rate of glycogen resynthesis was not significantly different in the four tests: 28 +/- 5, 26 +/- 6, 33 +/- 4, and 34 +/- 3 mmol glucosyl units x kg(-1) dry weight muscle x h(-1) for the control, glutamine, wheat- and whey hydrolysate ingestion, respectively. It is concluded that ingestion of a glutamine/carbohydrate mixture does not increase the rate of glycogen resynthesis in muscle. Glycogen resynthesis rates were higher, although not statistically significant, after ingestion of the drink containing the wheat (21 +/- 8%) and whey protein hydrolysate (20 +/- 6%) compared to ingestion of the control and free glutamine drinks, implying that further research is needed on the potential protein effect.
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Metabolism 2000 Dec;49(12):1555-60 Related Articles, Links
Intravenous glutamine does not stimulate mixed muscle protein synthesis in healthy young men and women.
Zachwieja JJ, Witt TL, Yarasheski KE.
Exercise and Nutrition Program, Pennington Biomedical Research Center, Baton Rouge, LA, USA.
We investigated the effects of a glutamine-supplemented amino acid mixture on vastus lateralis muscle protein synthesis rate in healthy young men and women. Three men and 3 women (27.8 +/- 2.0 yr, 22.2 +/- 1.0 body mass index [BMI], 56.1 +/- 4.5 kg lean body mass [LBM]) received a 14-hour primed, constant intravenous infusion of L[1-13C]leucine to evaluate the fractional rate of mixed muscle protein synthesis. In addition to tracer administration, a clinically relevant amino acid mixture supplemented with either glutamine or glycine in amounts isonitrogenous to glutamine, was infused. Amino acid mixtures were infused on separate occasions in random order at a rate of 0.04 g/kg/h (glutamine at approximately 0.01 g/kg/h) with at least 2 weeks between treatment. For 2 days before and on the day of an infusion, dietary intake was controlled so that each subject received 1.5 g protein/kg/d. Compared with our previous report in the postabsorptive state, amino acid infusion increased the fractional rate of mixed muscle protein synthesis by 48% (P < .05); however, the addition of glutamine to the amino acid mixture did not further elevate muscle protein synthesis rate (ie, 0.071% +/- 0.008%/h for amino acids + glutamine v 0.060% +/- 0.008%/h for amino acids + glycine; P = .316). Plasma glutamine concentrations were higher (P < .05) during the glutamine-supplemented infusion, but free intramuscular glutamine levels were not increased (P = .363). Both plasma and free intramuscular glycine levels were increased when extra glycine was included in the infused amino acid mixture (both P < .0001). We conclude that intravenous infusion of amino acids increases the fractional rate of mixed muscle protein synthesis, but addition of glutamine to the amino acid mixture does not further stimulate muscle protein synthesis rate in healthy young men and women.
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J Appl Physiol 2002 Sep;93(3):813-22 Related Articles, Links
Exercise-induced immunodepression- plasma glutamine is not the link.
Hiscock N, Pedersen BK.
Copenhagen Muscle Research Centre and Department of Infectious Diseases, Rigshospitalet, University of Copenhagen, DK-2100 Copenhagen, Denmark.
The amino acid glutamine is known to be important for the function of some immune cells in vitro. It has been proposed that the decrease in plasma glutamine concentration in relation to catabolic conditions, including prolonged, exhaustive exercise, results in a lack of glutamine for these cells and may be responsible for the transient immunodepression commonly observed after acute, exhaustive exercise. It has been unclear, however, whether the magnitude of the observed decrease in plasma glutamine concentration would be great enough to compromise the function of immune cells. In fact, intracellular glutamine concentration may not be compromised when plasma levels are decreased postexercise. In addition, a number of recent intervention studies with glutamine feeding demonstrate that, although the plasma concentration of glutamine is kept constant during and after acute, strenuous exercise, glutamine supplementation does not abolish the postexercise decrease in in vitro cellular immunity, including low lymphocyte number, impaired lymphocyte proliferation, impaired natural killer and lymphokine-activated killer cell activity, as well as low production rate and concentration of salivary IgA. It is concluded that, although the glutamine hypothesis may explain immunodepression related to other stressful conditions such as trauma and burn, plasma glutamine concentration is not likely to play a mechanistic role in exercise-induced immunodepression
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Effect of glutamine and protein supplementation on exercise-induced decreases in salivary IgA.
Krzywkowski K, Petersen EW, Ostrowski K, Link-Amster H, Boza J, Halkjaer-Kristensen J, Pedersen BK.
The Copenhagen Muscle Research Centre, Rigshospitalet, 2200 Copenhagen, Denmark.
Postexercise immune impairment has been linked to exercise-induced decrease in plasma glutamine concentration. This study examined the possibility of abolishing the exercise-induced decrease in salivary IgA through glutamine supplementation during and after intense exercise. Eleven athletes performed cycle ergometer exercise for 2 h at 75% of maximal oxygen uptake on 3 separate days. Glutamine (a total of 17.5 g), protein (a total of 68.5 g/6.2 g protein-bound glutamine), and placebo supplements were given during and up to 2 h after exercise. Unstimulated, timed saliva samples were obtained before exercise and 20 min, 140 min, 4 h, and 22 h postexercise. The exercise protocol induced a decrease in salivary IgA (IgA concentration, IgA output, and IgA relative to total protein). The plasma concentration of glutamine was decreased by 15% 2 h postexercise in the placebo group, whereas this decline was abolished by both glutamine and
protein supplements.None of the supplements, however, was able to abolish the decline in salivary IgA. This study does not support that postexercise decrease in salivary IgA is related to plasma glutamine concentrations.
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Effect of carb intake on plasma glutamine
Int J Sport Nutr 1998 Mar;8(1):49-59 Related Articles, Links
Effect of low- and high-carbohydrate diets on the plasma glutamine and circulating leukocyte responses to exercise.
Gleeson M, Blannin AK, Walsh NP, Bishop NC, Clark AM.
School of Sport and Exercise Sciences, University of Birmingham, Edgbaston, England.
We examined the effects of a low-carbohydrate (CHO) diet on the plasma glutamine and circulating leukocyte responses to prolonged strenuous exercise. Twelve untrained male subjects cycled for 60 min at 70% of maximal oxygen uptake on two separate occasions, 3 days apart. All subjects performed the first exercise task after a normal diet; they completed the second exercise task after 3 days on either a high-CHO diet (75 +/- 8% CHO, n = 6) or a low-CHO diet (7 +/- 4% CHO, n = 6). The low-CHO diet was associated with a larger rise in plasma cortisol during exercise, a greater fall in the plasma glutamine concentration during recovery, and a larger neutrophilia during the postexercise period. Exercise on the high-CHO diet did not affect levels of plasma glutamine and circulating leukocytes. We conclude that CHO availability can influence the plasma glutamine and circulating leukocyte responses during recovery from intense prolonged exercise.
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Clin Nutr 2002 Oct;21(5):423-9 Related Articles, Links
Carbohydrate supplementation during intense exercise and the immune response of cyclists.
Bacurau RF, Bassit RA, Sawada L, Navarro F, Martins E Jr, Costa Rosa LF.
Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Brazil.
OBJECTIVE: To evaluate the effect of carbohydrate supplementation upon some aspects of the immune function in athletes during intense indoor cycling. METHODS: Twelve male athletes cycled for 20 min at a velocity corresponding to 90% of that obtained at the anaerobic threshold and rested for 20 min. This protocol was repeated six times. The athletes received, during the trial, water ad libitum, or a solution of carbohydrate (95% glucose polymers and 5% fructose) at 10% (w/v), 1 g kg h every 20 min, starting at the 10th minute of the first exercise period, plus extra water ad libitum. RESULTS: Exercise induced a reduction in peripheral blood mononuclear cell proliferation (37%) as well as in the production of cytokines by cultured cells (interleukin-1 (IL-1), interleukin-2 (IL-2), tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma), by 37%, 35%, 26% and 16%, respectively). All of these changes were prevented by the ingestion of a carbohydrate drink by the athletes, except that in IFN-gamma production, which was equally decreased (17%) after the second trial. The concentration of plasma glutamine, an important fuel for immune cells, was decreased in the placebo group but maintained in the group that received carbohydrate. CONCLUSION: Carbohydrate supplementation affects positively the immune response of cyclists by avoiding or minimizing changes in plasma glutamine concentration
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An excerpt from "Appetite For Construction
Building Results From Research"
by John M. Berardi
Should I Spend my Hard-Earned Money on Glutamine or Hookers?
.... A high protein diet provides a big whack of glutamine as it is. In fact, if you follow standard bodybuilding protein recommendations, about 10% of your total dietary protein intake is composed of glutamine (milk proteins are composed of somewhere between 3 — 10% glutamine while meat is composed of about 15% glutamine). This means that a high protein diet (400g/day) already provides me with about 40g of glutamine.
• While the theorists still cling to the idea that since glutamine helps clinical stress, it might help with exercise stress, it‚s important to note that exercise stress has got nothin‚ on surgery, cancer, sepsis, burns, etc. For example, when compared with downhill running or weight lifting, urinary nitrogen loss is 15x (1400%) greater in minor surgery, 25x (2400%) greater in major surgery, and 33x (3200%) greater in sepsis. When it comes to the immune response, it‚s about 9x (800%) greater with surgery. When it comes to metabolic increase, it‚s 7x (600%) greater with burn injury, and when it comes to creatine kinase release; it‚s about 2x (100%) greater with surgery. As I said, exercise has got nothin‚ on real, clinical stress. It‚s like trying to compare the damage inflicted by a peashooter and that inflicted by a rocket launcher.
• The major studies examining glutamine supplementation in otherwise healthy weightlifters have shown no effect. In the study by Candow et al (2001), 0.9g of supplemental glutamine/kg/day had no impact on muscle performance, body composition, and protein degradation. Folks, that's 90g per day for some lifters.
• The majority of the studies using glutamine supplementation in
endurance athletes have shown little to no measurable benefit on performance or immune function.
• And with respect to glycogen replenishment in endurance athletes, it's interesting to note that the first study that looked at glycogen resynthesis using glutamine missed a couple of things. Basically, the study showed that after a few glycogen depleting hours of cycling at a high percentage of VO2 max interspersed with very intense cycle sprints that were supramaximal, a drink containing 8g of glutamine replenished glycogen to the same extent as a drink containing 61g of carbohydrate.
The problem was that during the recovery period, a constant IV infusion of labeled glucose was given (i.e., a little bit of glucose was given to both groups by IV infusion). While this isn't too big of a deal on its own since the infusion only provided a couple of grams of glucose, the other problem is that during glycogen depleting exercise, a lot of alanine, lactate, and other gluconeogenic precursors are released from the muscle.
What this means is that there's a good amount of glucose that will be formed after such exercise, glucose that will be made in the liver from the gluconeogenic precursors and that will travel to the muscle to replenish glycogen. Therefore, without a placebo group that receives no calories, carbohydrates, or glutamine, we have no idea of knowing whether or not the placebo would have generated the same amount of glycogen replenishment as the glutamine group or the glutamine plus carbohydrate group. To say it another way, perhaps there's a normal glycogen replenishment curve that was unaffected by any of the treatments.
• And finally, with respect to the claims that glutamine might increase cell swelling/volume (something I once believed was a reality), we decided to test this theory out in our lab using multifrequency bioelectric impedance analysis as well as magnetic resonance spectroscopy. The pilot data that's kicking around has demonstrated that glutamine supplementation has no effect on total body water, intracellular fluid volumes, or extracellular fluid volumes (as measured by mBIA) and has no effect on muscle volume (as measured by nMRS)...
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J Appl Physiol 2002 Sep;93(3):813-22 Related Articles, Links
Exercise-induced immunodepression- plasma glutamine is not the link.
Hiscock N, Pedersen BK.
Copenhagen Muscle Research Centre and Department of Infectious Diseases, Rigshospitalet, University of Copenhagen, DK-2100 Copenhagen, Denmark.
The amino acid glutamine is known to be important for the function of some immune cells in vitro. It has been proposed that the decrease in plasma glutamine concentration in relation to catabolic conditions, including prolonged, exhaustive exercise, results in a lack of glutamine for these cells and may be responsible for the transient immunodepression commonly observed after acute, exhaustive exercise. It has been unclear, however, whether the magnitude of the observed decrease in plasma glutamine concentration would be great enough to compromise the function of immune cells. In fact, intracellular glutamine concentration may not be compromised when plasma levels are decreased postexercise. In addition, a number of recent intervention studies with glutamine feeding demonstrate that, although the plasma concentration of glutamine is kept constant during and after acute, strenuous exercise, glutamine supplementation does not abolish the postexercise decrease in in vitro cellular immunity, including low lymphocyte number, impaired lymphocyte proliferation, impaired natural killer and lymphokine-activated killer cell activity, as well as low production rate and concentration of salivary IgA. It is concluded that, although the glutamine hypothesis may explain immunodepression related to other stressful conditions such as trauma and burn, plasma glutamine concentration is not likely to play a mechanistic role in exercise-induced immunodepression.
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Am J Physiol Cell Physiol 2001 Oct;281(4):C1259-65 Related Articles, Links
Effect of glutamine supplementation on exercise-induced changes in lymphocyte function.
Krzywkowski K, Petersen EW, Ostrowski K, Kristensen JH, Boza J, Pedersen BK.
Copenhagen Muscle Research Centre and Department of Infectious Diseases, Rigshospitalet, 2200 Copenhagen N, Denmark.
The purpose of this study was to investigate the possible role of glutamine in exercise-induced impairment of lymphocyte function. Ten male athletes participated in a randomized, placebo-controlled, double-blind crossover study. Each athlete performed bicycle exercise for 2 h at 75% of maximum O(2) consumption on 2 separate days. Glutamine or placebo supplements were given orally during and up to 2 h postexercise. The trial induced postexercise neutrocytosis that lasted at least 2 h. The total lymphocyte count increased by the end of exercise due to increase of both CD3(+)TCR alpha beta(+) and CD3(+)TCR gamma delta(+) T cells as well as CD3(-)CD16(+)CD56(+) natural killer (NK) cells. Concentrations of CD8(+) and CD4(+) T cells lacking CD28 and CD95 on their surface increased more than those of cells expressing these receptors. Within the CD4(+) cells, only CD45RA(-) memory cells, but not CD45RA(+) naive cells, increased in response to exercise. Most lymphocyte subpopulations decreased 2 h after exercise. Glutamine supplementation abolished the postexercise decline in plasma glutamine concentration but had no effect on lymphocyte trafficking, NK and lymphokine-activated killer cell activities, T cell proliferation, catecholamines, growth hormone, insulin, or glucose. Neutrocytosis was less pronounced in the glutamine-supplemented group, but it is unlikely that this finding is of any clinical significance. This study does not support the idea that glutamine plays a mechanistic role in exercise-induced immune changes.
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