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LAST LECTURE WE TALKED ABOUT
DIETARY WATER IN SPORTS
TODAY WE WILL TALK ABOUT
SUPPLEMENTS
Lecture 17
SUPPLEMENTS
OUTLINE OF LECTURE 17
INTRODUCTION
CRITERIA FOR SUPPLEMENT USE
SUPPLEMENTS-EVALUATION-DO THEY
REALLY WORK?
SUPPLEMENTS-IDENTIFIED AND USES IN:
-ANAEROBIC
-INTERVAL
-AEROBIC
SUPPLEMENTS-ARE THEY WORTH IT?
SUPPLEMENTS
INTRODUCTION
long history of chemical use to try and boost
performance
not all of these chemicals are from food
doping-ethics
in theory the best athlete is a product of genes,
coaching, sports dietitian direction(good diet),
training
Criteria for supplements
Are they safe, effective, legal and have effects
superior to a proper diet?
If legal (or not illegal?) then how know if they are
safe and effective and indeed safe and effective at
what dose and at what timing and in conjunction
with which diet, which training and with which
drugs the athlete may be taking?
Just because something is natural that does not
make it legal, safe, effective and have effects
superior to a good diet.
Supplement evaluation- how to know if they
really work
Clear hypothesis?
Study on cells, muscle, animals or humans?
Claims for a population based on basis of population
based in study?
External variables controlled?
Placebo controlled?
Adequate techniques?
Trials randomised?
Cross-over design used?
Random assignment to groups?
Statistics?
Other studies confirm?
In peer reviewed journals?
Supplement evaluation- how to know if
they really work
Hypothesis
1. A tentative explanation for an observation,
phenomenon, or scientific problem that can be tested by
further investigation.
2. Something taken to be true for the purpose of
argument or investigation; an assumption.
Supplement evaluation- how to know if
they really work
Clear Hypothesis
Clear hypothesis-two caffeine tablets
delivering a total dose of 200 mg of
caffeine and taken 1 hour before a 100
metre sprint will decrease time to sprint
the 100 metres in males and females
aged 19-25.
Supplement evaluation- how to know if
they really work
Unclear hypothesis-caffeine tablets
improve sprint performance.
Supplement evaluation- how to know if they really
work
Study on cells, muscle, animals or humans?
Cell culture,
whole muscle preparations,
and animals
are not whole humans
Supplement evaluation- how to know if
they really work
Claims for a population based on basis of
population based in study?
What works well in one population eg marathoners
may not work well in sprinters
Must compare apples with apples and not
apples with oranges
Supplement evaluation- how to know if
they really work
External variables controlled?
Only difference between the groups can be the
agent
(active or placebo) used
Placebo and active agent must look the same, taste
the same, and in no way be distinguishable from
one another –why?
Supplement evaluation- how to know if
they really work
Placebo controlled?
If prior knowledge or expectations of what one is
receiving then this can affect performance-how?
Single and double blinding
Supplement evaluation- how to know if
they really work
adequate techniques used?
is there normally a lot of day to day variability in
the outcome measure(s)(eg endurance)
-sufficient sensitivity of instruments?-small
differences that could explain winning may not be
able to be detected
Supplement evaluation- how to know if
they really work
Trials randomised?
-someone not associated with trial is given subject
names and numbers which are then randomised by
computer to receive placebo or treatment
administering an active agent to people you know are
faster does not show that the active agent causes
improved performance
Supplement evaluation- how to know if
they really work
Cross-over design used?
Advantages- better control and can use small
numbers to meet power requirement
Power requirement – enough subjects in each group
to be 100 percent sure that you are 95 percent
positive
Parallel design- randomised controlled trial – what
this does to power requirement
Supplement evaluation- how to know if
they really work
Random assignment to groups?
- computer assignment better-never allow self
selection- eg those most motivated to lose weight
would choose active agent believed to cause weight
loss
- in other words this causes bias in the results
Supplement evaluation- how to know if
they really work
Statistics?
-the wrong statistics applied gives the wrong answer
-also must control for multiple comparisons being
done
Supplement evaluation- how to know if
they really work
Other studies confirm?
If the result is important others will attempt to
repeat it
Supplement evaluation- how to know if
they really work
in peer reviewed journals?
Peer review process
-can be great in theory but can be lousy in
practice
-conflicts of interest eg somebody’s friend does the
review
-politics
-stealing of data
NOW ONTO INDIVIDUAL
NUTRITIONAL SUPPLEMENTS
Androstenedione
-supposedly anabolic ie builds muscle for
eg 100 metre sprinting
-does not work
Bee Pollen
-rich in vitamins, minerals and amino
Acids and on that basis
Alleged to:
improve endurance
reduce free radical damage
control weight
increase longevity
prevent asthma
-all false
Beta alanine and carnosine
Beta alanine synthesised in body to carnosine
Carnosine is a buffer against intracellular
acid- eg lactic acid
Eg 400 metre sprinting- some success
HMB-beta hydroxy beta methylbutyrate
-metabolite of leucine in the body
-consumption of HMB alleged to build
lean (muscle mass) and hence increase
strength- not a sure thing-not everyone
agrees
Fig. 12-7, p. 392
Fig. 12-7, p. 392
Boron
alleged to increase muscle mass in
strength athletes-no evidence of such
Caffeine
-improve high intensity exercise (near
100 % VO2 max lasting for 3-8
minutes) decreases sprint times- 6
mg/kg bw)-not all studies agree
-endurance exercise- endurance
improved with 1-9 mg/kg bw-most but
not all studies agree with this
Fig. 12-7, p. 392
Fig. 12-7, p. 392
L-Carnitine
What does the L mean?
transports fatty acids into the mitochondria
for catabolism via Krebs cycle-does not work
for endurance exercise
Slimming agent- does not work
Fig. 12-7, p. 392
Fig. 12-7, p. 392
Fig. 12-7, p. 392
Choline
-role of acetylcholine-neurotransmitter
-depleted during endurance (32 km)
running-report
-improves endurance running
performance in at least one study but
this was not universally found
-no grounds for universal
recommendation
Chromium
-some say it is a fat burner and a
muscle builder-no solid evidence to support this claim
38
Coenzyme Q10
-part of the electron transport chain
-said to improve VO2 max and increase
energy and stamina but no real
evidence to support this
-may increase free radical production
-nothing really to support its use
Creatine
-part of creatine phosphate
-during intense maximal exercise
(anaerobic) it contributes significantly
production of ATP
-roughly 67 percent of studies in favour
with 33 percent against benefits
40
Fig. 12-7, p. 392
Fig. 12-7, p. 392
Fig. 12-7, p. 392
Fig. 12-7, p. 392
Fig. 12-7, p. 392
Fig. 12-7, p. 392
Creatine
Most success in anaerobic
Less so in interval
No real success in endurance (aerobic)
47
DHEA
-supposed muscle builder
-irrelevant as IOC banned with zero
tolerance
48
Fish oil
-cell deformability and theoretical
improved oxygen delivery
-still hypothetical
49
Ginseng
No evidence to suggest that ergogenic
aid
50
Glycerol
-only a small contributor to
gluconeogenesis- so no real help
-pre-exercise hyper-hydration
-draws water into extracellular
space
-decreases urination
-if sufficient water ingestion there is
indication of reduced heat stress
-no real proof of increased endurance yet
51
Fig. 12-7, p. 392
Inosine
-converted to a molecule in the body
that helps release oxygen but no
improvement in endurance or interval
-said to increase ATP but no
improvement in sprinting or interval or
endurance
53
Lactate salts and polylactate
-heart fuel
-no indication that these 2
improve performance
54
Lecithin
contains choline and phosphorous
no evidence of it being ergogenic
We have lots of it to begin with
55
Medium chain triacylglycerol
-6-10 carbon fatty acids (6-12 in other
books)
-more easily digested and absorbed than
LCTs
But- next slide-small contribution to
energy and does not affect
glycogen breakdown
-therefore not ergogenic
56
Fig. 12-7, p. 392
Pangamic Acid
supposedly reduces lactate and
increases maximal oxygen uptake
both claims false
FDA prohibits sale as dietary
supplement or drug
58
Phosphatidylserine
part of cell membranes
no demonstrated ergogenic effect
59
Phosphorous
-part of ATP and CrP
-many studies-no indication of
improved performance in
endurance activities
60
Pyruvate and Dihydroxyacetone
(DHA)
part of glycolysis which they
supposedly speed up
controversial in endurance as to
whether improved performance
61
Sodium bicarbonate
buffer- pH control-lactate
improved performance with
sodium bicarbonate for
anaerobic sports
optimal dose is 300 mg/kg b.w.
1-2 hours before event
62
Fig. 12-7, p. 392
Sodium bicarbonate
but get diarrhea, cramping,
bloating at this optimal dose
64
Sodium citrate
-increased efflux of ions from cell
-improved pH
-300-500 mg/kg b.w.
-best for anaerobic
-same problems as with bicarbcramping, diarrhea, bloating
65
Vanadium
supposed improved glucose transport
into cells but does not work in
athlete
therefore not ergogenic
66
Wheat germ oil
-has linoleic acid, vitamin E
-no ergogenic effect
67
Fig. 12-7, p. 392
Fig. 12-7, p. 392
SUPPLEMENTS ARE THEY WORTH IT?
REMEMBER!!
Are you informed about all the ingredients in the product? (If you
are unsure of what you are consuming, you should not take that
particular product.)
• Do you know if the product is safe (from a short- and long-term
health perspective)? A product that is promoted as "natural" is not
guaranteed to be safe.
• Does the product contain any banned or restricted substances from
the WADA list? (If you are unsure of what you are consuming, you
should not take that particular product.)
• Have you sought professional advice from medical, physiological
and/or nutritional experts?
• Is your training plan optimal (in terms of nutrition, recovery, and
mental and physical preparation)? COST OF SUPPLEMENTS?!!
SUPPLEMENTS –are they
worth it? Contaminants
Beware the internet and even some shops on the
ground
ephedrine-stimulant-appetite control
-banned by IOC
strychnine-stimulant-banned by IOC
various steroids that can lead to a positive
steroid drug test
71
SUMMARY OF LECTURE 17
INTRODUCTION
CRITERIA FOR SUPPLEMENT USE
SUPPLEMENTS-EVALUATION-DO THEY
REALLY WORK?
SUPPLEMENTS-IDENTIFIED AND USES IN:
-ANAEROBIC
-INTERVAL
-AEROBIC
SUPPLEMENTS-ARE THEY WORTH IT?
Fig. 12-7, p. 392
Fig. 12-7, p. 392