"Pre-workout", the name says what this type of supplement is for, namely before intake before training. You take pre-workouts to immediately raise your sports performance to a higher level. To achieve this goal, a pre-workout is aimed at improving energy levels, strength, and endurance. Almost every pre-workout contains ingredients from these three categories, possibly supplemented with extras.
Components that increase energy levels include caffeine, L-tyrosine, phenylethylamine, hordenine, rhodiola, higenamine, and dendrobium. DMAA (1,3-dimethylamylamine) has also been a popular energy booster in many pre-workout formulas. From 2012, however, DMAA is no longer permitted in the Netherlands.
Ingredients that increase focus and energy levels often also have a positive effect on strength and stamina. Most pre-workouts also contain substances that are specifically intended to increase the strength level. The best-known example of this is creatine. Beta-alanine is also part of many pre-workout formulas. In particular, this material maintains the strength level under long-term loading. So you can say that this supplement increases both strength and endurance. The same can be said of L-arginine and L-citrulline. These amino acids are also known for their ability to stimulate the release of nitric oxide (NO). NO promotes, among other things, vasodilation; this means a greater blood supply to the muscles and the "pump" so desired in bodybuilding.
How do you make a good choice from the huge range of pre-workouts? First of all it is wise to know which characteristics of a pre-workout you find the most important. Are you mainly looking for a product that will give you a good wake-up at the end of a long, tired day? In particular, make sure that the energy-generating ingredients are sufficiently present. If strength, endurance or NO production are important to you, pay attention to the presence of substances that are responsible for those specific properties. Do not blindly assume that when a manufacturer places a claim on the label, the product actually has that property. Look critically on the label for the precise dosage of each component. If this is not clear, for example because only the total number of milligrams of a "mix" or "blend" is specified, assume that the producer has something to hide. An example of a completely transparent product is Bezerk 100%, this supplement shows exactly what the content of each measuring scoop is up to the milligram.