What Is Pre-Workout
Pre-workout is a general category of supplements taken before a workout with the goal of increasing energy and improving performance. Most pre-workouts contain a stimulant as well as specific amino acids for promoting blood flow and delaying fatigue.
Some of the most common ingredients are caffeine, l-arginine (or l-citrulline), and beta-alanine.
Caffeine For Energy
Caffeine works by binding to adenosine receptors in the brain to block signals of fatigue. As a result, you feel more energized and focused.
This is helpful during a workout because it can improve your stamina6. In addition, studies suggest that caffeine has a positive effect on metabolic rate which can promote fat loss7.
A typical dosage is 150 to 250 mg, but you should adjust this based on your body size and tolerance.
L-Arginine Or L-Citrulline For Blood Flow
L-arginine is an amino acid that relaxes blood vessels and allows more blood to pass through. This temporary increase in vascularity and muscle volume is called “the pump”.
With increased blood flow, more oxygen and nutrients get into the muscles. And that can enhance recovery and growth. For resistance training workouts, 5 grams is a good dosage.
L-citrulline works with arginine to extend the pump. Allowing harder training sessions, faster recovery, and potentially greater muscle gain. The recommended dosage of citrulline is 2-6 grams.
Beta-Alanine For Performance
Beta-alanine delays fatigue by buffering the pH levels in the presence of lactic acid. This allows longer, more intense training sessions.
In fact, a meta-analysis showed that people supplementing with beta-alanine significantly increased their exercise capacity9. That is, the amount of time they could work before getting fatigued.
An effective dose of beta-alanine is 2-3 grams.