wk10 Flashcards
where is caffine metabolised
the liver
when does caffein intake kick in and peak
peaks around 60mins after ingestion, will kick in after 5-15 mins
how does caffeine act within the body
interacts with all cells and crosses the blood brain barrier
what is the caution around amount of caffeine
minimal amounts give same effect as large, however more leads to higher chance of risk and negative side effects
what are the effects of caffeine
- Improved vigilance and alertness
- Reduced perception of effort
- Reduced fatigue
- Reduced pain
- Improved performance
how does caffeine work
- Adenosine causes fatigue – caffeine stops this from binding by being a similar structure
- Caffeine stimulates lipolysis
- Caffeine stimulates calcium release
what is diff about calcium increase with caf
has to be in a very high amount to increase calcium, evidence not trusted
how does caf help endurance event
Caffeine will directly increase triglyceride breakdown and indirectly increase epinephrine, this helps to save muscle glycogen stores as they’re spared
optimal dose of caf
3mg/kg bw taken 40-60 mins before exercise
no more than 200 at a time
max of 400 a day
what is the best co ingestion for caf
with a high% cho drink
examples of when to take caf
- Endurance sports >60min
- Brief sustained high intensity sport 1-60min
- Team and intermittent sports – high work rates and concentration needed
- Pre-training boost
- Single efforts involving strength or power
risks of caf
- Affects sleep onset and quality
- dehydration
- Anxiety
- Jitters
- GI unrest
- Insomnia
- Irritability
what does acidosis do
inhibits glycolysis (PFK) reducing ATP production, causes fatigue
what is beta alanine
beta amino acid precursor of carnosine
what is carnosine
dipeptide made up of two amino acids (beta-alanine and histidine)
where do you find carnosine
found in skeletal muscles, plays part in pH buffer. found in redmeat and chicken and fish
how long of beta alanine supplementation do you need before results
4 weeks
what is the mechanisms of taking more beta alanine
Chronic beta-alanine supplementation increases muscle carnosine
Higher levels of carnosine enhance intracellular buffer of H+ ions during anaerobic glycolysis
Higher buffering capacity = delay fatigue
what is the supplementation regime for beta alanine
Loading dose – 3.2g/day for 8 weeks or 6.4g/day for 4 weeks
Maintenance dose – 1.2g/day
Consume in split doses with meals to enhance uptake and reduce side effects
what are the side effects of beta alanine
- high doses can lead to paraesthesia (pins and needles tingling sensation) for up to hours
- skin rashes
what does sodiim bicarb do
(NaHCO3) – a extracellular (blood) buffer, important role in maintaining pH
how does bicarb buffer
Bicarbonate binds with hydrogen ions, this forms carbonic acid and leads to water and carbon dioxide which can be exhaled
what does bicarb buffer leas to
- Less fatigue
- Higher muscle metabolic function
- Higher exercise capacity (anaerobic)
what is the supplement regime for bicabrb
Single dose – consume 60-180mins before exercise
Smaller, multi-day protocols last 3-7days and can help reduce side effects
Acute dose (2-3h before exercise) – 200-300mg/kg body mass + 10mL/kg body mass fluif + 1.5g/kg body mass CHO, to consume slowly over 30-60min
what are the side effects of bicabr
- gastrointestinal upset
- Nausea
- Stomach pain
- Diarrhoea
- Vomiting
- Weight gain
what does split dose mean
smaller doses giving the same total intake over 60-180 mins
what is serial loading
multi day, with 3-4 smaller doses per day for 2-4 consecutive days prior to an event
