In recent years, a family of food supplements called generically supplements has entered the world of sports supplementation "Pre Workout”. This definition encompasses all those supplements made up of mixtures of elements which have the objective of increasing the psychophysical abilities of the athlete , and which must be taken just before training.
These supplements are best taken before exercise and typically contain a blend of ingredients that tend to maximize your ability to train hard in different ways. Among the elements that make up these combinations we can find, for example, beta-alanine, amino acids, nitric oxide , but also creatine : the association of these elements in the right quantities can in fact elicit a synergistic effect on exercise performance with a result immediate, increasing what could be the action of the individual ingredients taken alone.
But what are the ingredients that should make up the perfect Pre-Workout and what does scientific research tell us about it?
Caffeine
Widely studied in the scientific literature, caffeine seems to be the main ingredient responsible for many of the effects linked to a rapid increase in 
performance of Pre Workout supplements.
This immediate effect occurs due to its rapid absorption by the body, causing it to reach its peak in the bloodstream within 60 minutes of ingestion. Furthermore, caffeine acts as an adenosine receptor antagonist, and has been shown to significantly improve cognitive abilities and physical performance during exercise , increasing parameters related to endurance and Energy when consumed in dosages ranging from 3 to 6 mg/kg of body weight.
Pre Workout formulations that contain at least 300mg of caffeine per serving will be within the acceptable dosage range for most individuals, thereby ruling out possible undesirable effects.
Amino acids
Among the amino acids studied, taurine is certainly one of the most interesting, which has been reported in the scientific literature for its antioxidant, metabolic and ergogenic effects.
Taurine is present in eggs, fish, meat and milk, but not in foods of plant origin. In the adult body, taurine can still be synthesized in the liver starting from cysteine and methionine (two other amino acids) in the presence of sufficient quantities of vitamin B6, but constant consumption of the substance can improve the duration of the exercise during a performance of endurance .
Pre-workout ingestion of 1.5g of taurine as part of a Pre-Workout Blend has been shown to significantly improve muscular endurance during weight-bearing exercise . Branched Chain Amino Acids (BCAAs) are also often added to some pre-workout blend formulations with the intention of increasing the rate of protein synthesis while minimizing protein degradation, thereby reducing exercise-induced muscle damage. exercise.
Nitric oxide stimulators
Nitric oxide ( NO, or more correctly nitric oxide) is an endogenous mediator of particularly important processes, such as vasodilation and the transmission of nerve impulses. It is a molecule of fundamental importance, which has been shown to be able to increase the amount of blood flow to the muscles during physical activity , consequently leading to a possible increase in physical performance.
Several components used within the Pre–Workout (such as arginine and citrulline) have the ability to increase nitric oxide levels, without posing a health risk.
Another NO stimulant is dietary nitrate , a compound found in beetroot juice that appears to improve endurance and high-intensity exercise performance when consumed in doses of 300 mg or higher.
L-arginine is a precursor amino acid required for the synthesis of nitric oxide. While some studies have shown benefits from oral consumption of L-arginine, most of the evidence suggests that arginine has limited effectiveness in improving blood flow or performance.
As far as L-citrulline is concerned, this molecule is a non-essential amino acid found mainly in watermelon (from which it took its name, from the Latin citrullus ) which is converted into L-arginine and therefore promotes the synthesis of nitric oxide. L-citrulline supplementation has been shown to increase vasodilation and improve exercise performance when consumed in doses of 6-8g per day.
Creatine
Creatine is a naturally occurring amino acid found in the muscles of various animals. Creatine supplementation is safe and it has been extensively demonstrated over the years that taking this amino acid can increase intramuscular phospho-creatine levels by 30% after supplementation with approximately 5g (0.03g/kg/dose ) per day after a loading period of 20 g/day (0.3 g/kg/day).
This regimen continued to have a positive impact on high-intensity exercise performance when consumed in doses of approximately 3-5 g/day after a loading period of 20 g/day. In general, regular consumption of at least 3 g of creatine, contained in a Pre-Workout blend, per day for at least 28 days is reasonably sufficient to improve physical performance and increase training adaptations .
Beta Alanine
β -alanine is a very common component in pre-workouts: it is a precursor of carnosine (a small protein composed of the amino acids histidine and alanine), a dipeptide that acts as an intramuscular buffer .
Consumption of 4-6 g of β-alanine per day, over a period of at least 2 weeks, has been shown to improve high-intensity exercise performance . Therefore, provided a pre-workout blend contains sufficient amounts of β-alanine, similar performance effects can be expected when adequate levels of intramuscular carnosine are consumed daily.
Pre-Workout Conclusions
In conclusion, to date we can say that most of the current literature would suggest that supplementation with these products improves various types of physical performance and 
can enhance training-induced adaptations in a safe way, without side effects.
When combined in the right way in a reasonable blend, these effects are maximized resulting in increased capabilities of the nervous and musculoskeletal systems . However, if you have any health concerns it is always recommended that you discuss the specific product intake and dosages of any supplement with a health professional, expert or sports dietician before ingesting any product.
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