ex nutr c10-supplement1 introduction ergogenic aids, or nutrition supplements 500-400 b.c. enhance...

Ex Nutr c10-Supplement 1

Introduction

Ergogenic aids, or Nutrition supplements 500-400 B.C. Enhance performance Influence by manufacturers

Weight loss and muscle gain Nutritional supplements are used by

40-100% athletes Over 600 nutrition supplements

Ex Nutr c10-Supplement 2Clinical Evaluation of Nutrition Supplements Studies Does the study have a clear hypothesis? Was the study on cell, muscle, animals, or humans? Was the population for which claims are made

comparable to the population in the study? Were external variables controlled? Was the study placebo controlled? Were adequate techniques used? Were the trials randomized? Was a crossover design used? Was it random assignment or was self-section used? Do other studies confirm the findings? Was the study peer reviewed?


Androstenedione

Claim: increase testosterone, muscle mass, and improve recovery

most popular supplement in USA Used by Mark McGwire when broke MLB single

season HR record 1994 allowed to sell as food supplements No supporting evidence Decrease HDL-C IOC banned, MLB banned in 2006


New drugs tetrahydrogestrinone （ THG ）全新的藥物，和已知的類固醇在結構上有很大的不同

直到 2003 年 6 月，一位匿名的教練將一支含有 THG 的針筒寄到美國藥檢局總部

位於舊金山的運動營養品公司－ Bay Area Laboratory Co-Operative （ BALCO ）提供 THG 給運動員

Jason Giambi, Barry Bonds, Roger Clemens, Marion Jones, Montgomery 等可能使用


tetrahydrogestrinone （ THG ）


Bee Pollen

Claim: Increase energy level, enhance physical fitness and improve endurance, and boosts immune function

Reduces free-radicals, weight control, longevity, and prevent asthma

No supporting evidence

Ex Nutr c10-Supplement 11Beta-Hydroxy Beta Mtheylbutyrate (HMB) A metabolite of Leucine (Fig 10.2) Synthesis rate 0.2-0.4 g/day Popular among body builders Claimed

Increase LBM, strength and improve recovery Increase immune function, lower cholesterol, stress,

reduce body fat For both endurance and strength athletes


HMB metabolism

Nissen SL, 1997

Ex Nutr c10-Supplement 13Beta-Hydroxy Beta Mtheylbutyrate (HMB)

41untrained subjects, 3 wk weight training Control, 1.5 g/day, 3.0 g/day


Boron 硼 In noncitrus fruits, leafy vegetable, nuts, and

legumes. Improve bone density, muscle mass, and

strength Improve bone mineral density in post-

menopausal women, not in men


Caffeine Paleolithic time – brew a drink for stimulus properties Stimulate central nervous system Stimulate release of epinephrine Improve high-intensity and endurance exercise, fat oxidation ↑Post-exercise glycogen recovery? Effective dosage 3-15 mg/kg, ~1 hr before exercise

Not a banned substance any more 70 kg male, consume 100 mg, ~1.5 ug/ml urine Safe dosage 8-10 mg/kg (recommend <7, usually 3-5 mg/kg) 100-150 mg in a cup of coffee, 20-50 mg in a cup of tea, 35-55 mg

in a can of coke Individual difference in effect, dosage, excretion

Adaptation, may need to avoid caffeine Purified caffeine in capsule may better than coffee


Effect of Caffeine in Performance Endurance exercise

Ingested 1 h before exercise Increase FA conc., decrease muscle glycogen utilization

- improve endurance performance Not all studies found performance improved: Dosage,

fitness level, habitual caffeine consumption, and duration of exercise

Maximal exercise 6 mg/kg improve time to exhaustion at 100%VO2max Muscle glycogen still high at exhaustion neuromuscular pathway? muscle ion handling? enhance

anaerobic energy production? 150-200 mg improve 1500 m (4:46-4:50)


Effects of Caffeine in Performance

Supramaximal Exercise: Uncertain No effect in 15-second sprint, 30 s Wingate test

Cognitive function Caffeine (2-3 mg/kg) + carbohydrate

electrolytes drink Improve cognitive functioning (attention,

psychomotor skills, memory) Improve concentration

Ex Nutr c10-Supplement 25Meta-analysis of caffeine on endurance performance (vs placebo)

Conger SA, 2011

Ex Nutr c10-Supplement 26Meta-analysis of caffeine on endurance performance (vs CHO)

Conger SA, 2011


L-Carnitine 肉鹼 from meat and dairy products, popular

among athletes Also endogenous production from

methionine and lysine Synthesis in liver, ~27g stores, 98% in skeletal

muscle and heart muscle Lost from only urine and stool

Claim ↑VO2max, muscle, fat oxidation, spare muscle

glycogen ↓lactate, fat mass


Carnitine in fat metabolism

Transport long-chain FA across Mitochondrial inner membrane

Maintaining acetyl-CoA/CoA ratio Action on PDH Acetyl-CoA + carnitine –> acetyl-carnitine +

CoA Reduces lactate production, may enhance high

intensity exercise


Carnitine as a slimmer agent

Regular ingestion of carnitine increases muscle carnitine concentration which may increase fat oxidation?

No effect 6 g/day for 14 days did not increase in muscle

carnitine concentration Human muscle has more than enough free

carnitine for CPTI to maximal activity


Carnitine in Performance

Endurance exercise theory – increase muscle carnitine concentrations NO effect in fat oxidation and glycogen

breakdown NO effect in performance during prolonged

cycling or running exercise High-intensity exercise

No effect on VO2max, performance and lactate accumulations


Choline

Acetylcholine precursor Abundant in meat and dairy products,

lecithin, pysophatidylcholine and sphiongomyelin

Strenuous exercise decrease plasma choline Supplementation no effect on performance


Chromium 鉻 Fat burner and muscle builder Claim: ↑Insulin action, ↑ protein synthesis

Essential for insulin sensitivity Evans 1989 – 40-42 days weight training +

200 ug/day Chromium Subsequent data did no confirm the results May cause chromosome damage


Coenzyme Q10

ETC in mitochondria Used in CVD patients for recovery Functions – improve oxidative metabolism

Exercise capacity Antioxidant – free radical

NO effects on VO2max, performance, lactate conc.

Free radicals?


Creatine Popular after 1992 Olympic game

Linford Christie (100 m), Sally Gunnell (400 m hurdle) 1996 Atlanta – 80% athletes used creatine 3,000,000 kg/year Ingestion 2g/day, breakdown 2g/day into creatinine

and excreted in the urine Primary source in fish and red meat Vegan depends on endogenous synthesis 70 kg man – 120g creatine, 95% in muscle Creatine synthesis in liver and kidney Type II has 30% more than type I


Creatine in the metabolic process Phosphocreatine (PCr) + ADP + H+ Creatine

(Cr) + ATP Muscle 30% ATP falls – muscle fatigue PCr stores can be depleted in 5 s ↑creatine conc creatine kinase

↑ PCr synthesis Safety: generally safe, minor side effects

Gastrointestinal, cardiovascular and muscular problems Nausea, vomiting, diarrhea Alterations in kidney and liver function Muscle cramps Elevated blood pressure


Creatine supplementation

Harris et al. 1992 5 g creatine 4-6 times/day 30% increase in PCr

Greenhaff 1993 20 g/day for 5 days improve 6% repeated bout maximal knee ex.

In 1999 – 62 studies, 42 positive results


Creatine Loading Regimens

Loading + maintenance 20 g/day (5g for 4 times) 6 days increases

muscle creatine by 25 mmol/kg, ~20% Follow up by 2 g/day maintain for 35 days 3 g/day for 28 days = rapid loading Initial muscle concentration 160 mmol/kg dw – maximal conc. Ingest with simple carbohydrate solution


Creatine and Weight Gain

20 g for 6 days – 0.5-3.5 kg weight gain Increase intracellular water Increase protein synthesis Decrease protein breakdown

10 wks weight training + creatine 20-25% increase in maximal strength 60% fat free mass increased

Allow more repetitions – better training quality Negative effect on weight bearing activities?

Running, Gymnastics


Creatine and performance

High-intensity exercise, repeated exercise 70% of all studies – improve in strength, force

production or torque 25 g for 6 days, 10X6s sprints 20 g for 5 days, 2X30s

Endurance exercise: No effect


Mechanism of Creatine Action

Increased PCr stores – especially in type II Increased PCr resynthesis Increased use of PCr, reduced anaerobic

glycolysis and lactic acid formation Buffer of hydrogen ion


ATP shuttling Creatine important in

shuttling high-energy phosphate from mitochondria to myofibrils

Potential mechanism for Cr in improving endurance exercise performance Endurance performance

NOT affected


Dehydroepiandrosterone (DHEA)

DHEA, DHEAS Stimulate muscle growth Olympic Committee banned


Fish Oil

No effects on performance Need further study

May benefit health Cardiovascular disease Fat/cholesterol metabolism inflammation


Ginseng

Improve VO2max? Running performance in rats!!

Inconsistent results


Glycerol

A substrate as glyconeogenesis Convert into glucose in the liver as fuel As hyperhydrating agent

Act like a sponge Increase plasma osmolarity 1g/kg bw in 1-2 L water

Banned by WADA


Inosine, Lecithin

Inosine: Nucleoside, ATP structure Claim: ↑ ATP stores, ↑ muscle strength, ↑

oxygen delivery, ↑ endurance No evidence

Lecithin: phosphotidylcholine Claim effects: similar to choline No effect on performance


Lactate Salts and Polylactate

Lactate – energy source for heart Lactate salt – sodium or potassium lactate

10 g without any gastrointestinal problem Polylactate – low in bioavailability No effect on performance


Medium Chain Triacylglycerol MCT FA contain 8-10 carbons May elevated plasma FA and spared muscle

glycogen – improve performance CHO, CHO+MCT, MCT 57% VO2max, 180 min Contribute to total energy expenditure is small

MCT rapid emptied from stomach Ingest 20 g MCT does not affect muscle

glycogen breakdown Probably no positive effect on performance


Pangamic Acid

Vit B15 Increase VO2max, reduce lactate formation,

improve performance No effect Not Vitamin Synthetic pangamic acid is harmful – FDA

forbid the sale as dietary supplement or as a drug


Phosphatidylserine, Phosphorus

Phosphatidylserine Soy bean Decrease in stress Inconclusive in exercise performance

Phosphorus Phosphate loading – 4 g/day ↑VO2max?, ↓lactate ? Inconsistent findings, need further confirmation


Pyruvate (and dihydroxyacetone)

Claim:↑ fat oxidation, ↑ muscle glycogen storage, ↑ endurance capacity, ↓ fat mass

Stanko et al. 1990 – 75 g DHA+25g pyruvate ↑ VO2max and endurance time

Morrison et al. 2000 – 7 g/day, 7 days No change

More studies are needed


Sodium Bicarbonate / citrate

Maximal exercise ↑acidity ↓performance Alkalizers may buffer the acidity

sodium bicarbonate, sodium citrate ↑lactate efflux from muscle cell, ↑plasma lactate Fitness and skill performance?

H++HCO3- <-> H2CO3 <-> H2O+CO2

200-300 mg/kg 1-2 h before exercise improve performance

Side effects Diarrhea, GI discomfort, Bloating, cramp


Vanadium / Wheat Germ Oil

Vanadium Trace elements Insulin-like effects –↑glucose uptake, but only in

type II diabetes or glucose intolerance subjects No evidence support in healthy subjects

Wheat Germ Oil Claim: increase endurance, stamina, and vigor No effect


Contamination of Supplement

Banned products in nutritional supplements Nandrolone, 19-Norandrostenedione, 19-

norandrostenediol ephedrine, DHEA

94 in 634 (15%) dietary supplements tested positive in IOC-accredited lab in Cologne Contain enough anabolics to cause positive result

on drug test ~20% in 240 US-made supplements

contained prohormones


Erythropoietin (EPO)

First generation of erythropoietin: Epoetins recombinant human erythropoietins that have

the same amino acid sequence as endogenous EPO.

glycosylation varies 3 currently commercially available types of

epoetin (alpha, beta and omega) contain a higher proportion of sialylated, acidic carbohydrate residues than endogenous EPO.

injected 2-3 times/week


Erythropoietin (EPO)

Second generation: darbepoetin alfa (Aranesp), glycoengineering of EPO differs from endogenous erythropoietin by containing

two more N-linked oligosaccharide chains Injected every 1-2 weeks

Third generation: CERA (Continuous Erythropoiesis Receptor Activator) methoxy polyethylene glycol-epoetin beta, addition of

polyethylne glycol molecule longer duration of action, injection every 3-4 weeks,

WADA started to detect in Tour de France 2008 and 2008 Olympics


Beullens M, Blood 2006

Possible false-positive in urine EPO test


Human growth hormone

GH increases plasma free FA and glycerol Decrease protein oxidation during exercise Increase protein synthesis, decrease fat mass in

untrained men Probably ineffective in athletes

no evidence that GH enhances muscle strength, power, or aerobic capacity in trained adult athletes

GH increase anaerobic exercise capacity accelerating recovery from soft-tissue injury,

increase collagen synthesis


Growth hormone in ex performance

Birzniece, 2011


Punishment to reduce cheating

Incentive to winning in big events is too high Athletes are willing to take risk in health,

punishment Increased punishment in bigger events may

reduce athlete’s incentive to cheat

ex nutr c10-supplement1 introduction ergogenic aids, or nutrition supplements 500-400 b.c. enhance...

Documents

muscle mass

vo2max muscle glycogen

muscle glycogen utilization

endurance performancenot

effect of caffeine

study placebo

study peer

muscle ion handling