Stimulant Supplements Flashcards
Give 2 effects of stimulants
- Change in mental function and behaviour (increase alertness)
- Production of excitement/euphoria
- Reduce sensation of fatigue
- Increase motor activity
State 2 legal stimulants
Caffeine Guarana Yerba Mate Ma Huang/Ephedra Ginseng
State 2 illegal stimulants
Cocaine
Ephedrine
Amphetamines
What is the half life of caffeine
5 hours
What is the maximum dose of caffeine
6mg/kg/BW
What does caffeine antagonise
cerebral adenosine receptors
Where is caffeine detoxified for excretion
The liver
Give 2 factors which could affect caffeine impact
Hepatic dysfunction
Habituation
Dose
True or False: Caffeine increases lipolysis
True
How does caffeine increase the force of muscular contraction
By causing a release of Ca2+ from the SR, which binds to troponin, allowing cross-bridge formation
What are the central effects of caffeine
Increases norepinephrine/epinephrine
When caffeine increases norepinephrine/epinephrine, what does this increase?
Fat oxidation- CHO sparing
How does caffeine increase altertness
The adenosine receptors it targets cause sonambulance/decreased alertness, so by blocking these alertness is increased.
Give 3 examples of food/drink which contain caffeine
Coffee
Tea
Cola/Energy drinks
Chocolate
What is the precursor of caffeine that dark chocolate contains?
Theobromine
Which extracellular ion does Caffeine lower? and how?
Potassium - Na/K pump
How does caffeine affect blood pressure
Blood pressure also increased with caffeine due to the stimulation of the sympathetic nervous system.
How does caffeine effect RER
No effect
How does caffeine effect fat oxidation
despite the elevated lipolysis, no fat oxidation occurred above normal levels (but may be some effects at lower intensities
How does caffeine extend time to exhaustion
prolonging the maximal lactate steady state concentration until fatigue. It also reduced rate of perceived exertion
Jeukendrup 2008 showed combined caffeine and glucose supplementation decreased fat oxidation, and increased CHO utilisation (from liver or exogenous). How was lipolysis effected
no effects of lipolysis due to the CHO introduction
Jeukendrup 2008 showed combined caffeine and glucose supplementation decreased fat oxidation, and increased CHO utilisation (from liver or exogenous). How was performance effected
There was an improved performance, by a quicker time trial with caffeine consumption.
True or false: Caffeine is a diuretic
False
How does caffeine improve concentration
- Keeping you awake
- Giving you a clear mind
- Increasing energy
- Increasing alertness
True or false: caffeine is effective for both single and multiple sprints
False- no effect on single sprints
State the fastest method of caffeine delivery
Caffeine gum
Give 2 positive effects of caffeine gum
Faster method of delivery and no GI side effects/co-ingestion required. Improved performance.
Give 3 side effects of caffeine
• Poor sleep quality (if taken later in the day due to half life) o Harder to get to sleep o Decreased drowsiness o Poorer actual quality • Anxiety • Tachycardia • Blurred Vision
Describe
Peripheral Nerve and Transcranial Magnetic Stimulation
extensor
Different areas of the cortex effect different portions of the body.
What does an EMG test show
the membrane potential of motor units
What does MEP amplitude show
the excitability of the muscle.
What does a twitch in torque show
reduced voluntary action. Whereas no twitch = 100% voluntary action.
What can MEPs show during MVC
determine central fatigue.
Bowtell 2018 showed caffeine affected muscle pH- how?
Muscle pH was lower with caffeine
Bowtell 2018 showed there was increased voluntary activation both pre and post exercise- what does this show
caffeine reduces central fatigue
How did a berocca drink affect RPE
decreased RPE significantly during exercise
