The advertisements are everywhere you look in the fitness world. It is unsurprising since the margins are reportedly huge. Pre-workout supplements seem to promise all things to all people. Need more energy? We got you. Faster recovery? Of course. More/better/faster muscle gain or weight loss? Expensive but worth it. Let’s examine those claims.

For a different audience it may be worth noting the supplement industry is largely unregulated. From you I expect a shoulder shrug or gales of laughter. Of course, you don’t need no stinking authority to tell you what works and what doesn’t. There is actual research that has evaluated the utility of the substances in many pre-workout supplements.

Pre-workout supplements usually contain a proprietary blend of ingredients. While manufacturers insist that their unique blend is responsible for the energy boost, there is invariably just one ingredient producing the buzz: caffeine. Pre-workout supplements are loaded with it. Many leading brands range anywhere from 150 mg to 300 mg per dose. A typical cup of coffee has 100 mg.

Pre-workout supplements contain other ingredients that athletes and bodybuilders regularly use, including creatine, L-arginine, β-alanine, taurine, and betaine.

Irrespective of exercise, caffeine is known to increase metabolic rate, improve endurance, and reduce fatigue. It also stimulates the central nervous system, enhancing brain function for a more productive and effective workout.

Creatine is one of the most popular bodybuilding supplements. Creatine is synthesized from amino acids and concentrated in muscle tissues to enable quick bursts of energy, like sprinting or powerlifting. According to a review of studies published in the Journal of the International Society of Sports Nutrition, creatine supplementation is effective in promoting muscle growth, strength, and performance during high-intensity interval training.

L-arginine is one of the branch-chained amino acids necessary for protein synthesis. L-arginine is also central to creating nitric oxide, a compound that relaxes your blood vessels for better blood flow and oxygen exchange. Despite these metabolic functions, there is little scientific evidence to support claims that supplementation can improve athletic performance.

β-alanine, also known as beta-alanine, is a naturally occurring amino acid produced in your liver that promotes nerve signal function. Some studies have suggested that supplementation may delay the onset of neuromuscular fatigue and enhance athletic performance. On the downside, the supplement can sometimes overstimulate nerve cells, causing tingling sensations known as paresthesia. Because the incidence of this side effect can vary by dose, it is often better to take an individual supplement to better control intake.

Taurine is one of the most abundant amino acids found in the brain, muscles, and organ tissues. It functions as a neurotransmitter, stabilizing cell membranes and regulating the transport of nutrients throughout the body. There is conflicting evidence as to the role taurine supplementation plays in improving athletic performance. According to research published in the Journal of Strength and Conditioning Research, the combined use of taurine and caffeine may accelerate, rather than delay, muscle fatigue.

Betaine is an amino acid that helps process fat and maintain normal liver function. A small study (23 people) conducted in 2013 suggested that betaine supplementation improved body composition, muscle size, and work capacity in bench press and back squat training. Betaine supplementation did not appear to increase strength.

This week’s music is for db whose eyes were recently opened. It’s also a reminder Sarah Silverman once had a sense of humor. Is this the sequel? You be the judge.