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Gemma Bridge

HHP
Chapter 25: Ergogenic Aids

06/02/15

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What is an ergogenic aid?
Why must an investigator use a placebo treatment to evaluate the effectiveness of an ergogenic aid?
Provide a brief summary of the role that dietary supplements play in improving performance
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How is this possible?
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How might ingested buffers improve short term performance?
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Why?
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Chewing tobacco may provide a nicotine high, but it is not without risks
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Describe different types of warm up activities and the mechanics by which they may improve
performance
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This is because the
effect of the aid is dependent on a range of factors, such as:
 Amount of substance
o Too little or too much may show no effect
 Subject
o May be effective in “untrained” but not “trained” subjects, and vice versa
o The “value” as determined by the subject
 Task
o Endurance vs
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fine-motor activities
 Use
o May enhance short-term performance but compromise long-term performance

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HHP
06/02/15
Due to the variables scientists must be careful not to be fooled by the result
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results obtained on a
proper subject population can be generalized, but it is important to realize that conducting research in a lab
the results may not be generalisable to the wider population out in the field
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Many dietary supplements are available and most claim to improve performance
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The breathing of oxygen enriched mixtures and blood doping are two
ergogenic aids that have been used to influence oxygen delivery
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Explained further below…
Prior to exercise
Breathing 100% oxygen prior to exercise would increase the oxygen bound to hemoglobin by 3%, or 6
millimeters
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This could add 100 ml of additional stored O2 in the blood

Gemma Bridge
HHP
06/02/15
for someone with a total blood volume of 5L
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During exercise
The rationale of using oxygen during exercise is based upon the proposition that muscle is hypoxic during
exercise and additional oxygen delivery will alleviate the problems
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 Rationale is to prevent muscle hypoxia by delivering additional O2
o Increase in O2 content of arterial blood is balanced by decrease in blood flow to muscle
o No real increase in oxygen delivery to muscle
 Only 2–5% increase in VO2 max
 However, there is an increase in time to exhaustion
o Beneficial in athletes who experience desaturation during exercise
o High PO2 slows glycolysis and reduces lactate and H+ formation
 Not practical for use in performance
After exercise
 Rationale is to speed recovery and be ready for second bout of exercise
 Early results suggested it works
o However, the subjects knew they were breathing oxygen
 Later research showed no benefit
o No improvement in recovery HR, ventilation, or post-exercise VO2
o No improvement in subsequent performance
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How is this possible?
Blood doping
 Infusion of RBCs to increase hemoglobin concentration and oxygen carrying capacity of blood
o Autologous transfusion
 Uses subject’s own blood
 Homologous transfusion
 Uses matched donor
 Effects of infusion of 900 ml blood
o Increase [Hb] 8–9%
o Increase VO2 max 4–5%
o Increase performance 3–34%
 Effects last for 10–12 weeks
 Erythropoietin (EPO)
o Hormone that stimulates RBC production
o Part of therapy for chemotherapy or dialysis patients
o Can lead to extremely high RBC
 Has led to death of athletes
 Testing for EPO use or RBC infusion
o Hematological passport
 Tracks athlete’s blood over years to detect sudden changes

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 Artificial oxygen carriers or Hemopure
o Not shown to improve performance

HHP

06/02/15

In the early days of research the athletes own blood was needed to achieve the goal of higher [Hb]
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 Mismatch between maximum time blood could be refrigerated for and the time period needed for the
subject to produce new RBC’s and bring the [Hb] back o normal before reinfusion
o Maximum storage time= 3 weeks, but 1% RBC’s in storage lost per day
 Some RBC’s stick to storage containers or lose function due to fragility
 Only 60% of RBC’s removed can be reinfused
 Main reason why in the early days that studies showed inconsistent changed in VO2 max and
performance with blood doping
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 Needed a sham withdrawal, and a sham reinfusion
Freezer preservation technique allowed for more careful study of blood doping
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 Allows for athlete to become normocythemic so that any effect of reinfusion can be evaluated
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Ingested Buffers
Improvements in aerobic, endurance performance focus on the supply of carbohydrate and oxygen to the
muscles
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 Emphasis on buffering H+ released from muscle
o Blood buffers (sodium bicarbonate)
 Enhances ability to buffer H+ during exercise
 Improves performances of 1–10 minutes duration or repeated bouts of high-intensity exercise
o No benefit for tasks of less than one minute
 Optimal dose
o 0
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These drugs are
readily absorbed by the small intestine and have a peak affect 2-3 hours after ingestion, but can have lasting
effects for up to 24 hours
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Caffeine is absorbed quickly from the
GI tract and is significantly elevated in the blood 15 minutes after ingestion, and the peak concentration is
achieved 60 minutes after
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Caution should be taken when
extrapolating the research because caffeine’s ergogenic effect on performance is variable, and appears to be
dose-related and less pronounced in subjects who are daily users of caffeine
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However as it is part of cigarettes and chewing tobacco it is
one of the most abused products
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 Causes both physiological and psychological changes that are beneficial to performance
o Increased muscle temperature, arousal, focus
on event
 Warm-up activities
o Identical to performance
o Directly related to performance
o General warm-up



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