Ergogenic Aids
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Transcript of Ergogenic Aids
NUTRITIONAL SUPPLEMENTS FOR ATHLETES
LIV ENGELSEN, MS
Ergogenic Aids
OutlineRegulation of nutritional supplementsIn-depth review of 5 popular ergogenic aids
Caffeine Creatine Monohydrate Sodium Bicarbonate β – Alanine HMB
Overview of research to support/refute additional supplements/practices
The best recovery beverage of all time…Summary/Conclusion
DefinitionSubstances, devices or practices that
enhance an athlete’s energy use, production or recovery
RegulationRegulated by the Dietary Supplement Health
and Education Act of 1994 (DSHEA)
http://www.youtube.com/watch?v=3vxrTMYXpZo
Caffeine Most popular social drug in the US
Average adult ingests 3 mg/kg of caffeine daily Alkaloid stimulant found in coffee, tea, colas, sports drinks,
chocolate, etc. Has been studied for its ergogenic effects for ~100 years Levels of caffeine in foods vary greatly depending on preparation
Coffee: 60-150 mg/cup Tea: 40-60 mg/cup Cola: 40-50 mg/cup Chocolate (1.5 oz): 20 mg dark/9 mg milk
Ergogenic effectiveness varies, depending on:o Age o Gender o Body sizeo Caffeine toleranceo Habituationo Cessation patterns
Mechanisms of Action
Global effects on the CNS Caffeine is a competetive, nonselective adenosine receptor antagonist Leads to delayed fatigue, increased mental alertness, mood improvement,
energetic arousal Enhances concentration, visual acuity, reaction time and self-reported fatigue
Effects on hormonal, metabolic, muscular, cardiovascular, pulmonary and renal functions during rest and exercise. Leads to decreases in respiratory exchange ratio (RER), peripheral fatigue, rating
of perceived exertion (RPE), and threshold for exercise-induced cortisol and B-endorphin release
Leads to increases in oxygen uptake, cardiac output, ventilation, circulating levels of epinephrine, metabolic rate, and fat oxidation during endurance exercise in trained and untrained individuals
Bottom Line: The mechanisms by which caffeine improves athletic performance is multifactorial and extends well beyond any one biologic mechanism!
Effects on Body Systems & Sports Performance
Tolerance Diminished responsiveness resulting from repeated exposure Caffeine tolerance has been associated with increased
adenosine receptor activity and a decrease in β-adrenergic activity
Lower caffeine doses are well tolerated by nonusers Complete tolerance can occur in 5-6 days of moderate caffeine intake Effective strategy for a nonuser: 3-4 days of consecutive caffeine use to aid intense
workout sessions Begin with 1-2 mg/kg and increase progressively over the next few days
Psychological Factors
Withdrawal Withdrawal symptoms peak in 28 to 48 hours Takes an average of 4 to 7 days to return to baseline Main symptom is frequent and severe headaches
2/2 vasodilation of cerebral blood vessels Resumed or acute caffeine intake almost entirely reverses
withdrawal symptoms, including headache Regular caffeine users can optimize benefits by cutting back,
but must be careful to avoid withdrawal symptoms Reduce caffeine intake gradually at least 1 wk before competition Resuming caffeine on the day of competition will again provide the desired
ergogenic effects, as it would for a nonuser
Intake Strategy Caffeine reaches a peak plasma level between 30 and 75
minutes of ingestion Half-life is 4 to 5 hours with modest intake, but longer when
dose exceeds 300 mg In 6 to 7 hours, 75% of caffeine is cleared from the body
because it is rapidly absorbed and metabolized by the liver Intake strategy is crucial for those seeking to improve
athletic performance through caffeine use
Dosing As little as 1 mg/kg to as much as 13
mg/kg had positive effects on time to fatigue in endurance events, sports, and sprint or power events. 1 to 7 cups of coffee 3 to 18 cups of tea or soda
Some studies have found better ergogenic effect with lower dose (3-6 mg/kg) than higher doses No evidence of greater ergogenic effects with
more than 9 mg/kg Higher caffeine intake may blunt cognitive
performance Gender differences
Men tolerate higher doses than women
Safety Concerns The common belief that caffeine leads to dehydration and
causes poor athletic performance is a misconception! Claims of adverse effects of caffeine on the cardiovascular
system are inconclusive. The high levels of antioxidants found in coffee and tea have
been linked to a number of health benefits Protection against heart disease and type II DM
ResearchAuthor &
YearSubjects & Methods
Measures Treatment Results
Cox, et al., 2002
Effect of different protocols of
caffeine intake on metabolism and endurance perf.
12 trained cyclists/triathletes in study A, 8 in study B
Plasma/ urinry caff, rate of fat
oxidation,
1) Precaf2) Durcaf3) Coca-cola4) Placebo
Coca-cola was equally effective
in enhancing endurance
Hogervorst et al., 2008
Caffeine improves physical and
cognitive performance during exhaustive exercise
24 well-trained cyclists in a
RCCT
Series of cognitive and physiological
tests
1) CHO (CHO)2) Caffeine
+CHO (CAF)3) Placebo
(BEV)
Faster after CAF on both complex info processing
Maridakis et al., 2007
Caffeine attenuates delayed onset muscle pain
following eccentric exercise
9 low-caffeine consuming
females
Pain intensity, force loss during
eccentric and MVIC exercise
1) Caffeine2) Placebo
Large reduction in pain following
caffeine ingestion
Pedersen et al., 2008
High rates of muscle glycogen resynthesis after
exhaustive exercise when CHO is
coingested with caff
7 trained cyclists/triathlet
es in a Randomized, DB
Crossover design
BG, insulin, caff levels, muscle metabolites,
muscle glycogen,
protein kinases
1) CHO2) CHO + Caff
After 4 hrs of recovery, muscle
glycogen was higher in Caff
Think Fast!What has the highest caffeine
content?
a) Brewed teab) Shot of espressoc) Brewed coffeed) Dark chocolate bar
Creatine Monohydrate
An amine found naturally in some foods, particularly meat products.
Can be formed in the kidney and liver from glycine and arginine
Delivered to the muscle and combined with phosphate to create phosphocreatine: a high-energy phosphagen in the ATP-PCr energy system. ATP-PCr energy system is important for rapid energy production, such as in
speed and power events Supplements come in various forms; powders, pills, candy,
gels, etc. Marketed to both strength and endurance athletes
Appears most effective for activities that involve repeated short bouts of high-intensity physical activity
Ergogenic Benefits Recent studies have shown significant improvements in:
Total and maximal force in repetitive isometric muscle contractions Muscular strength and endurance in isotonic strength tests Muscular force/torque and endurance in isokinetic strength testing Cycle ergometer performance in maximal tests ranging from 6 to 30 seconds Field performance tests such as jumping, running, swimming, and skating.
Less consistent, but overall favorable
Exogenous Sources Average adult needs to replace ~2 grams of creatine/day for
maintenance of normal creatine and PCr levels. Daily creatine intake of carnivores is ~1 g/day Daily intake may be nearly zero for vegetarians
Endogenous creatine formation helps complement dietary sources to achieve 2 grams
Excessive amounts of exogenous creatine will not be stored, but will be excreted unchanged in the urine
Proposed Mechanisms Most of the creatine in the body is stored in the muscles
Research suggests that performance benefits are related to increased creatine within type II muscle fibers
60% of total muscle creatine is PCr, and 40% is free creatine Increasing the amount of PCr will provide more
substrate for generating ATP during high-intensity exercise, and higher levels of free creatine will help re-synthesize PCr.
Alternative theory: creatine supplementation and anabolic hormones?
Creatine Dosing Very effective quick strategy
20-30 g/day (5-7 g per dose over the course of the day) Significant effects seen after only 2 days
Long-term supplementation at lower dose is just as effective 4-5 g/day Significant effects seen after 6 days
Once loaded, ~2 g/day for maintenance Creatine supplementation appears safe when the
recommended loading and maintenance doses are followed
Special Considerations Research suggests people may be responders or non-responders
Characteristics of nonresponers include :1) Higher initial levels of creatine and PCr2) Fewer type II muscle fibers
Individuals with initially low levels of intramuscular creatine are more responsive to supplementation Vegetarians
Caffeine counteracts the ergogenic action of muscle creatine loading! Vandenberghe et al., 1996
Effect on body mass >50 studies have shown an increase in body mass
during the first week of creatine supplementation Increased creatine in the muscle draws water
Formulation- creatine monohydrate Theoretically, dehydration, muscle cramps
and heatstroke can occur Drink plenty of water!!!!!
Creatine supplementation enhances muscular performance during high-intensity resistance
exerciseVolek et al., 1997Subjects &
MethodsMeasures Treatment Results
•14 active men
•DB RCT
•Bench press (PB)protocol and jump squat (JS) protocol
•Three different occasions(T1, T2, T3)
•Each separated by 6 days
•Total reps for bench press•Peak power output for jump squats•Body mass•Skinfold thickness•Pre and post- exercise lactate
PL: PlaceboCR: Creatine
Prior to T1: No supplementation
Prior to T2: Everyone got placebo
Prior to T3: CR group took 25g/day for 6 days
•Lifting performance was not altered for either exercise after PL•CR improved peak power output during all 5 sets of JS and improvement in reps during all 5 sets of BPs. •CR increased body mass by 1.4 kg
Think Fast!For maintenance of normal creatine and PCr
levels, the average adult needs to replace ___ of creatine/day
a) 1 gb) 2 gc) 3 gd) 4 g
Sodium Bicarbonate Alkaline (buffer) salt found naturally in the body that helps
control pH and avoid excess acidity Increases pH Decreases H and lactate ions
During high intensity anaerobic exercise, energy needs are mainly provided by anaerobic glycolysis This is associated with a high level of lactic acid production Accumulation of excess lactic acid in the muscle cell interferes with
the optimal functioning of various enzymes, resulting in fatigue Increased perception of effort and decreased force production
Marketed to athletes as part of a sports supplement Not as popular as some of the other ergogenic aids available
Baking soda is a commercial version
Proposed Benefits Sodium bicarbonate supplementation increases serum pH
Desired effect is to buffer lactic acid Reduces acidosis in the muscle cell, decreases the
psychological sensation of fatigue, and increases performance in high-intensity anaerobic exercise tasks to exhaustion (~1-3 min of maximal exercise) 400 or 800-meter sprint 100 meter swims 5 km bicycle races
50% of well-controlled studies have demonstrated these effects
There is still conflicting research on the topic
Great individual variability in response
Safety & Side Effects Possible side effects of acute sodium bicarbonate
supplementation GI distress including nausea, diarrhea and cramping
Possibly due to an increase in gastric emptying following the ingestion of alkalotic agents Increased osmolality of the GI tract
Symptoms may be alleviated by drinking extra water with supplementation, however this may also impact the degree of alkolosis obtained
Dosage & Timing Supplements should be given 1-3 hours prior to exercise event
(90 minutes seems ideal) Leads to increased blood pH levels before, during and after an event
Most studies had subjects ingest 0.15- 0.30 g/kg 0.30 g/kg appears to be the optimum dose, with higher dosages providing no
additional benefit This is less than 1 oz for the average adult and appears to be effective and safe
Supplementation with lower doses over longer periods of time may be just as effective, with lower risk of adverse effects Take the same dose over 6 day period instead of at one time
Strategies to avoid/minimize GI distress during an event:a) Trial supplementation during trainingb) Drink plenty of water during treatmentc) After chronic ingestion for 5-6 days, d/c supplementation 2 days before the
eventd) Intravenous infusion
Sodium bicarbonate can be used as an ergogenic aid in high-intensity, comptetive cycle ergometry of 1 h duration
McNaughton et al., 1999
Subjects & Methods
Measures Treatment Results
•10 male, well trained cyclists
•3 tests, in a RDB fashion
Blood samples taken:
•90 min prior•every 30 min prior•10 min intervals throughout•1,3,5,10 min post-ex
Blood Analysis:•pH•Blood NaHCO3
•PO2•PCO2•Blood lactate
Ergometer Data:•Work output•Power output•Heart rate
C: control60 min ride
P: placebo60 min ride + equimolar dose of NaCl
E: experimental60 min ride + 300 mg/kg NaHCO3
•Subjects in E completed greater amounts of work than either C or P•Subjects in E had greater power output than C or P •No change in peak power or power:mass •Blood pH was increased in E prior to testing•Blood lactate was lower in E throughout test
Think Fast!Which of the following is NOT a strategy to
avoid or limit GI distress when taking NaHCO3?
a) Drink plenty of water during treatmentb) Intravenous infusion c) After chronic ingestion for 5-6 days, increase dose 2 days before
the eventd) Trial supplementation during training
β - Alanine Precursor for carnosine, a dipeptide found in high
concentrations in skeletal muscle Carnosine is synthesized from the amino acids L-histidine and
β–alanine β –alanine is the rate-limiting component in the process
Chronic ingestion of β–alanine can elevate the carnosine content of human muscle by up to 80%
Carnosine plays an important role in homeostasis of contracting muscle cells, especially during high rates of anaerobic energy delivery.
Carnosine Latin for “meat/flesh” Produced and stored in the skeletal muscle of animals but
virtually absent from other organs Absent from plants
Lacking in vegetarian diet Content is especially high in animals involved in sprint exercise
Chickens, greyhound dogs, horses Muscle carnosine content is highly individualized
Lower in women Declines with age Likely lower in vegetarians
β- alanine supplementation is one of the most powerful means to elevate musclecarnosine content More effective than carnosine ingestion alone
Proposed Mechanisms Carnosine loading leads to improved performance in high-
intensity exercise likely due to the following mechanisms
pH buffering Undisputable physiological role as determined by its molecular structure
Protection of proteins against glycation by acting as a sacrificial peptide
Preventing the formation of protein-protein cross-links Acting as an antioxidant Increasing calcium sensitivity in muscle fibers enhancing
force production and total work output
Dosing Considerations Daily doses of β –alanine in the amount of 4.8-6.4 grams can
elevate muscle carnosine content by 60% in 4 weeks 80% in 10 weeks
Baguet et al., showed that the increased carnosine content in calf muscles remained elevated for > 9 weeks following supplement cessation
Doses of >10 mg/kg should be avoided Can induce paraesthesia symptoms
No other side efects of β –alanine supplementation have been reported
Further research on the safety and possible side effects of β –alanine as a nutritional supplement is warranted.
Effects of β-alanine supplementation and high intensity interval training on endurance
performance and body composition in men; a double-blind trial
Smith et al., 2009
Subjects & Methods
Measures Treatment Results
•46 active college- aged men
•DB RCT
•6 weeks of HIIT consisting of 5-6 bouts of a 2:1 cycling work to rest ratio
Determination of VO2 peak•VO2 peak•VO2 TTE•VTCycling test•TTE•TWD•WBody composition•% body fat•Fat mass•Lean body mass
PL: placebo16.5 g dextrose
BA: β-alanine 1.5 g β-alanine + 15 g dextrose
First 21 days:4x/day (6 g/day)
Next 21 days:2x/day (3 g/day)
•Improvements in VO2 peak, VO2 TTEand TWD after 3 wks in both groups
•Increases in VO2 peak, VO2 TTEand TWD and LBM were only significant for the BA group after 2nd 3 wks of training
HMB
Hydroxy-beta-methylbutyrate A leucine-derived metabolite Positive effects on sports performance and as a therapeutical
supplement Demonstrated by Nissen et al. in 1996 Literature is conflicting
Reduces muscle damage and muscle catabolism and reinforces protein synthesis Used to minimize muscle wasting in AIDS patients
Background Branched-chain amino acids (BCAAs)
Leucine Isoleucine Valine
Leucine and its metabolite α-ketoisocaproate (KIC) have been known to be potent anti-catabolic compounds for >35 years Mechanisms not clearly established Isoleucine and valine are not able to trigger these effects
HMB may be one of the key elements in the anti-catabolic effect of leucine
HMB appears to be safe at doses of 3 g/day and may even have positive impacts on overall health Decreases in TC and LDL Decreases in systolic BP
Effects of amino acids supplement on physiological adaptations to resistance training
Kraemer et al., 2009
Subjects & Methods
Measures Treatment Results
17 healthy men in a DB RCT
Performed 12 wks of heavy resistance training
Blood samples taken every 2 wks
•Body mass•Lean body mass•% body fat•Muscle circumference•Maximal power•Testosterone•Cortisol•Growth Hormone•Creatine kinase
MA: Muscle Armor1.5 g HMB, 7 g arginine, 7 g glutamine, 3 g taurine, and dextrose
CON: ControlIsocaloric control
•MA led to greater gains in LBM, muscle strength and power•MA promoted increases in resting and exercise-induced testosterone and GH•MA decreased CK, indicating recuction in muscle damage
Limited/Unsupportive ResearchSupplement Proposed
ActionResearch to Support
Side Effects Legality
Carnitine Increases fat metabolism
Refutes, no benefits
None Legal
Chromium Increases lean muscle mass
Refutes, no benefit unless
prior deficiency
Potentially dangerous if >400 mg/day
Legal
Coenzyme Q10
Enhances electron
transport, improves
endurance
Limited, does not support use for
athletes
Appears safe Legal
DHEA(dehydroepiandrostero
ne)
Prohormone that increases lean muscle mass
Refutes, no benefits for
athletes
None Legal
MCT Increases energy and muscle cell
mass, delays fatigue
Limited Intestinal cramping and
diarrhea
Legal
Zinc Increases endurance,
mental alertness/concen
t.
Limited None if taken in recommended
doses
Legal
Supportive ResearchSupplement Proposed
ActionResearch to Support
Side Effects Legality
Anabolic Steroids
Increases strength, LMM &
Motivation
Supports Significant, dangerous
Illegal
Blood doping Increases aerobic capacity
Supports Significant, dangerous
Illegal
Energy Gels & Sports Drinks
Increases endurance by
supplying CHO, fluid and lytes
Supports None Legal
Growth Hormone
Increases LMM, strength & power
Supports Enlargement of organs &
increased risk of disease
Banned by WADA
Protein Optimizes muscular growth
& repair
Supports None unless underlying cond.
Legal
Chocolate milk
“Chocolate milk as a postexercise recovery aid appears to be as effective as another carbohydrate replacement beverage.” Pritchett et al., 2009
Summary Dietary supplements for athletes are not well regulated
May be contaminated May contain substances not on the label, or may not contain what it claims
to contain Research on most ergogenic aids is limited and often
conflicting – interpret with caution Most studies used low number of subjects Often poorly controlled
Role of the RD Inform clients of the efficacy and safety issues surrounding nutritional
supplements Focus on those that are evidence-based (there aren’t many)! Caution of those with limited/unsupportive research
Stress the importance of proper diet and fluid intake for athletic performance Hydration – 20-24 oz fluid replacement for every pound lost CHO & quality protein to fuel workouts – 3-4 hrs prior Anabolic window – up to 30 min post workout
ReferencesCox GR, Desbrow B, Montgomery PG, Anderson ME, Bruce CR, Macrides TA, Martin DT,
Moquin A, Roberts A, Hawley JA, Burke LM. Effect of different protocols of caffeine intake on metabolism and endurance performance. J Appl Physiol. 2002; 93: 990-999.
Derave W, Everaert I, Beeckman S, Baguet A. Muscle carnosine metabolism and beta-alanine supplementation in relation to exercise and training. Sprots Med. 2010; 40(3): 247-263.
Hogervorst E, Bandelow S, Schmitt J, Jentjens R, Oliveira M, Allgrove J, Carter T, Gleeson M. Caffeine improves physical and cognitive performance during exhaustive exercise. Med. Sci. Sports Exerc. 2008; 40(10): 1841-1851.
Kraemer WJ, Hatfield DL, Volek JS, Fragala MS, Vingren JL, Anderson JM, Spiering BA, Thomas GA, Ho JY, Quann EE, Izquierdo M, Hakkinen K, Maresh CM. Effects of amino acids supplement on physiological adaptations to resistance training. Med. Sci. Sports Exerc. 2009; 41(5): 1111-1121.
Maridakis V, O’Connor PJ, Dudley GA, McCully KK. Caffeine attenuates delayed-onset muscle pain and force loss following eccentric exercise. Journal of Pain. 2007; 8(3): 237-243.
McNaughton L, Dalton B, Palmer G. Sodium bicarbonate can be used as an ergogenic aid in high-intensity, competitive cycle ergometry of 1 h duration. Eur J Appl Physiol. 1999; 80: 64-69.
Pedersen DJ, Lessard SJ, Coffey VG, Chruchley EG, Wootton AM, Ng T, Watt MJ, Hawley JA. High rates of muscle glycogen resynthesis after exhaustive exercise when carbohydrate is coingested with caffeine. J Appl Physiol. 2008; 105: 7-13.
Pritchett K, Bishop P, Pritchett R, Green M, Katica C. Acute effects of chocolate mild and a commercial recovery beverage on postexercise recovery indices and endurance cycling performance. Appl Physiol Nutr Metab. 2009; 34: 1017-1022.
ReferencesRequena B, Zabala M, Padial P, Feriche B. Sodium bicarbonate and sodium citrate: ergogenic
aids? J. Strength Cond. Res. 2005; 19(1): 213-224. Smith AE, Walter AA, Graef JL, Kendall KL, Moon JR, Lockwood CM, Fukuda DH, Beck TW,
Cramer JT, Stout JR. Effects of β –alanine supplementation and high-intensity interval training on endurance performance and body composition in men; a double-blind trial. Journal of the International Society of Sports Nutrition. 2009; 6:5.
Sokmen B, Armstrong LE, Kraemer WJ, Casa DJ, Dias JC, Judelson DA, Maresh CM. Caffeine use in sports: considerations for the athlete. J Strength Cond Res. 2008; 22(3): 978-986.
Terjung RL, Clarkson P, Eichner R, Greenhaff PL, Hespel PJ, Israel RG, Kraemer WJ, Meyer RA, Spriet LL, Tarnopolsky MA, Wagenmakers AJM, Williams MH. The physiological and health effects of oral creatine supplementation. Med Sci Sports Exerc. 2000; 32(3): 706-717.
Vandenberghe K, Gillis N, Van Leemputte M, Van Hecke P, Vanstapel F, Hespel P. Caffeine counteracts the ergogenic action of muscle creatine loading. J Appl Physiol. 1996; 80(2): 452-457.
Volek JS, Kraemer WJ, Bush JA, Boetes M, Incledon T, Clark KL, Lynch JM. Creatine supplementation enhances muscular performance during high-intensity resistance exercise. J Am Diet Assoc. 1997; 97: 765-770.
Zanchi NE, Gerlinger-Romero F, Guimaraes-Ferreira L, Alves de Siqueira Filho M, Felitti V, Lira FS, Seelaender M, Lancha AH. HMB supplementation: clinical and athletic performance-related effects and mechanisms of action. Amino Acids. 2010; 130: 1937-1945
Questions?