8392 Lecture Notes - Lecture 16: Performance-Enhancing Substance, Blood Doping, Blind Experiment
20 Jun 2018
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Lecture 16
ERGOGENIC AIDS – Part 1
- Substances or phenomena that are work-producing and are believed to increase
performance
oNutrients
oDrugs
oWarm up exercises
oHypnosis
oStress management
oBlood doping
oOxygen breathing
oMusic
oExtrinsic biomechnical aids
- Research design concerns
oAmount of substance
Too little or too much may show no effect
oSubject
May be effective in ‘untrained’ but not ‘trained’ subjects and vice versa
The value as determines by the subject
oTask
Endurance vs short term events
Large motor vs fine motor activities
oUse
May enhance short term performance bu compromise long term
performance
oPlacebo
Look alike substance containing nothing that will improve performance
Athletes belief in a substance may influence performance
oDouble blind studies
Neither the investigators nor the subjects are aware of who is receiving the
treatment
- Oxygen
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oIncreases PO2 of blood
oHyperbaric chamber
Breathing air under higher pressure
21% (or higher) 02
No evidence of improved performance
Endurance run on treadmill and weightlifting
oIncreased %O2 mixtures
Breathing >21% o2 mixtures at atmospheric pressure
Improved time to exhaustion
Throughout range of inspired %o2
- Oxygen: prior to exercise
oRationale is to ‘store’ o2 in blood
Cannot really increase o2 bound to haemoglobin
97% saturated at rest (200Ml o2/L blood)
Increased by only 3% (6ml/l) breathing 100% o2
Can increase o2 dissolved in plasma
Dissolved oxygen increases from 3 to 21 ml o2/l blood
100 extra ml o2 stored in blood
However, blood o2 returns to noral within a few breaths of ir
oSome evidence that o2 breathin prior to exercise improves performance in short
events
Must takeplace within 2 min of event
Not practical for athletes
- Oxygen during exercise
orationale is to prevent muscle hypoxia by delivering additional o2
inc in o2 cntent of arterial blood is balanced by dec in blood flow to muscle
no real increase in o2 delivery to muscle
ony 2-5% increase in vo2 max
however, there is an increase in time to exhaustion
beneficial in athletes who experience desaturation during exercise
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high PO2 slows glycolysis and reduces lactate and hydrogen formation
onot practical for use in performance
- oxygen after exercise
orationale is to speed recovery and be ready for second bout of exercise
oearly results suggested it works
however the subjects knew they were breathing oxygen
olater research showed no benefit
no improvement in recovery HR, ventilation, or post exercise VO2
no improvement in subsequent performance
- physical warm up
ocauses both physiological and psychological changes that are beneficial to
performance
inc muscle temperature, arousal, focus on event
owarm up activities
identical to performance
directly related to performance
general warm up
- recommendations
oshort term performances (less than 10 sec max effort)
approx. 40-60% vo2 max for 5-10 min, followed by 5 min recovery
may reduce high energy phosphates
ointermediate term performances (more than 10 sec, less than 5 min)
approx. 60-70% vo2 max for 5-10 min, followed by less than 5 min recovery
goal to begin performance with slightly elevated vo2
olong term performance
approx. 60-70% v2 max for 5-10 min
too much may deplte muscle glycogen or increase thermal strain
- stretching
oinc joint flexibility
oinc muscle tendon compliance
oreduces risk of inury
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Substances or phenomena that are work-producing and are believed to increase performance: nutrients, drugs, warm up exercises, hypnosis, stress management, blood doping, oxygen breathing, music, extrinsic biomechnical aids. Too little or too much may show no effect: subject. May be effective in untrained" but not trained" subjects and vice versa. The value as determines by the subject: task, use. May enhance short term performance bu compromise long term performance: placebo. Look alike substance containing nothing that will improve performance. Athletes belief in a substance may influence performance: double blind studies. Neither the investigators nor the subjects are aware of who is receiving the treatment. Oxygen: increases po2 of blood, hyperbaric chamber. Endurance run on treadmill and weightlifting: increased %o2 mixtures. Oxygen: prior to exercise: rationale is to store" o2 in blood. Increased by only 3% (6ml/l) breathing 100% o2. Dissolved oxygen increases from 3 to 21 ml o2/l blood.
