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Summary HMS4602 Sports supplements and Ergogenic aids - All lectures and cases
This document provides all the lectures and cases of HMS4602.
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Voorbeeld van de inhoud
HMS2602 Sports supplements and Ergogenic aidsLectures and cases
Inhoud
Lecture Nitrate ........................................................................................................................................ 2
Lecture Creatine ...................................................................................................................................... 8
Lecture Buffers ...................................................................................................................................... 15
Lecture Micronutrients.......................................................................................................................... 19
Lecture Carnitine ................................................................................................................................... 23
Lecture Ketones ..................................................................................................................................... 27
Lecture Practical’s ................................................................................................................................. 31
Case 1: Popeye’s secret ......................................................................................................................... 34
Case 2 In search of the next magic bullet.............................................................................................. 43
Case 3 The sky is the limit...................................................................................................................... 54
,Lecture Nitrate
Nitrate and NO
NO metabolism
L-arganine with oxygen can be reduced by NOS to NO → can be transformed into NO which is then
transformed into nitrite and nitrate because NO is very volatile.
NO3 is nitrate, NO2 nitrite and NO is nitric oxide.
Under hypoxic and low pH nitrate (from for example beetroot juice) can be transformed into nitrite
and then into NO. This reverse pathway can be beneficial when more dietary nitrate is ingested.
Nitric oxide can aid in exercise efficiency, mitochondrial respiration, CA+ handling, vasodilation,
glucose uptake and muscle fatigue.
Nitrate metabolism
There is a primary and secondary pathways → explains when to take nitrate before exercise.
Primary pathway:
,Primary pathway: If you ingest nitrate → comes in your mouth you swallow it and it goes to your
stomach and to the upper part of your intestine where most nitrate is absorbed in your blood →
Blood is then going through your whole body and party goes in your mouth in saliva because there is
(about 25% higher than in normal circulation) active uptake of nitrate from the blood to the salivary
glands.
Primary → Mostly about nitrate absorption (25% of NO3 is taken up) the rest is excreted in urine.
Secondary pathway:
During the secondary pathway the nitrate absorbed by the salivary glands from the blood is reduced
to nitrite (happens to 5-7% of NO3 in the mouth) in the oral cavity. This is then swallowed in and
goes to the stomach due to the acidic environment some is reduced to NO immediately but most
goes to the intestines. There the nitrite is absorbed causing an increase in blood nitrite.
Secondary → What causes an increase in the nitrite concentrations in the circulation (5-7% of NO3 is
reduced to NO2 in the mouth)
Studies
First human studies showed that diet could reduce diastolic BP. (NO seems to be able to dilate
vessels to reduce BP).
Nitrate causes a lower O2 cost for submaximal exercise. A study used 6 days of 500 ml beetroot juice
(11.2 mol) → caused a lower VO2 and it improved the time till exhaustion (so they could last longer).
For actual good tests they needed a placebo that is similar in taste etc. to beetroot juice to do a
double blind randomized placebo controlled → they made a concentrated beetroot shot and they
made a placebo shot from which the nitrate was extracted → this was then often used in studies.
- 6 days of 140 ml beetroot juice (2 shots) per day (8 mmol) → 1.7% reduction in time in 10 km
time trial.
- An acute study of around 1 hr time trial with a 1 day 140 ml (8mmol) ingestion showed no
results between placebo and test subjects with nitrate beetroot juice.)
- Other studies showed again others things.
Open questions in 2012: How (salt, beetroot, juice..?) How much? How long? Who? When?
Mechanism?
, Nitrate and dose response
A study showed that 70 ml seemed not to be enough - for 140 and 280 ml it did show improvement
but the benefit was not greater for 280 ml than 140 ml.
Source, duration, sport discipline and elite athletes where investigated during the Beet-ing
competition study.
- They compared NaNo3, beetroot, arugula and spinach with a fully cross-over design (for all
they provided 800 mg of nitrate. They measured nitrate and nitrite and blood pressure.
- Maximum plasma nitrate levels where sort of the same but the time to reach the maximum
level was different (was faster for beetroot and NaNo3) and the same for nitrite levels
occurred. For arugula and spinach more digestion time is needed to free the nitrate.
- Systolic BP after 2,5 h was significantly different for beetroot and rocket and after 5 hours it
was only significantly lower for spinach.
NO causes production of cGMP which produces kinase G which then causes smooth muscle
relaxation, platelet inhibition and changes in gene expression. (Does not mean that nitrate does not
influence anything NO does, there are always more things of influence that we are not aware of)
Plasma concentrations where similar for 1-day to 6-day supplementation and there was no
difference between 1 or 6 day or placebo and exercise outcome.
We know now at this point:
- Nitrate ingestion: plasma No3 and NO2 increase
- Different sources:
o Plasma response similar
o Physiological response potentially different
- Exercise effects: improvement endurance exercise possible, but not in every study (even with
large dose), so dependent on several factors:
Nitrate and endurance sports performance
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