Dr. Dwayne Jackson

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Burning Questions

vital science - muscle & performance - questions

Burning Questions


We polled our resident supplement expert to answer our readers queries on the science of exercise and sports supplementation.


By Dwayne N. Jackson, PhD          




I already take a whey protein supplement; do I also need to take branched chain amino acids?


This is a question that we hear quite often. Which stands to reason since a lot of whey protein’s benefits are due to its relatively high branched chain amino acid (BCAA) content. The BCAAs are a group of three amino acids— leucine, isoleucine, and valine; where studies have shown that they reduce exercise fatigue, lower cortisol levels, and, promote anabolism (muscle building). However, to appreciate any ergogenic benefit from BCAA supplementation research shows that you must take in a minimum of 3 grams of leucine per serving—and you should take even more if you are musclebound, train intensely, or perform for long durations.

If you take a close look at most whey protein products, you will quickly see that they contain ~2 grams leucine, ~1 gram of isoleucine, and ~1 gram of valine per 20 gram scoop. So, if you are only taking a whey protein supplement with hopes of getting all that BCAAs have to offer, then you are shortchanging yourself. We recommend taking at least 5 g of BCAAs every time you drink a protein shake, especially 30-60 minutes before and after training or competing.


Are multivitamins even necessary?


Vitamins and minerals are essential catalysts for cellular function and nutrient absorption. They support growth and regeneration of various tissues in the body, including bones and muscle. Notably, our vitamin requirements increase when we train or engage in high intensity sports. To add insult to injury, intense training is commonly coupled with strict dieting which can exacerbate vitamin deficiencies.

Vitamins and minerals also play direct roles in brain function and neurotransmitter synthesis as well as indirect roles, through their involvement in energy metabolism and modulation of the brains blood supply. Further, many vitamins (and a number of minerals) have pivotal roles in mitochondrial function, the major site for energy (ATP) production. In the end, vitamin and mineral deficiencies can have profound effects on focus, energy, and metabolism— all of which have been shown to limit exercise and sports performance.

Notably, it is well documented that a large proportion of North Americans are deficient in one or more vitamins and minerals. For men and women who train or compete in sports, we always suggest using a high quality vitamin and micronutrient supplement formulated specifically for athletes to keep micronutrients topped up even under heavy training and/or dieting. Look for products with high levels of vitamin B,C, and D and take as directed. 


If my preworkout contains beta-alanine, do I still need the second post-workout dose?


YES! Beta-alanine, a precursor to carnosine (a dipeptide that is concentrated in skeletal muscle) synthesis, has been shown to elevate muscle carnosine levels by more than 60%. This is great for athletes, as increased muscle carnosine levels buffer exercise induced acidosis, resulting in increased power production and work capacity.

Based on an abundance of recent research illustrating its positive effects on muscle performance, most popular preworkout formulas contain beta-alanine. However, doses vary among products and even the best ones contain only 2-3 g of beta alanine per serving—this is about half of the optimal daily dose.

Here are 4 science backed points to consider when taking beta-alanine:

  • Four weeks of beta-alanine supplementation (4-6 g/day) significantly boosts muscle carnosine concentrations, which serve to buffer increases in acidity in exercising muscle.
  • The only substantiated side effect of high dose beta-alanine supplementation is a tingling sensation in the skin (called paraesthesia). Paraesthesia can be avoided by dividing your daily dose into 3 or 4 smaller doses (no more than 1.6 g each) and take them throughout the day.
  • Daily beta-alanine supplementation (4-6 g/day) for at least 2 to 4 weeks improves exercise performance, especially when exertion lasts between 1 and 4 minutes.
  • Beta-alanine becomes more effective when stacked with other supplements (like creatine). This synergy is not immediately apparent and generally becomes noticeable after 4 weeks of consistent supplementation.


I’m an athlete on a budget but want joint protection, is taking fish oil sufficient?


The omega 3 fatty acids [eicosapentaenoic (EPA) and docosahexaenoic acid (DHA)] in fish oil do provide a moderate level of joint protection, mainly due to their effects on reducing systemic inflammation—as seen in cases of rheumatoid arthritis. The best way to ensure you are getting all the benefits of fish oil, you should be making sure to take in at least 1200 mg of EPA and DHA per day, which equates to taking in about 4 g of fish oil per day (2 g with breakfast and 2 g with dinner).

If you want to ‘level up’ on joint protection, we recommend adding glucosamine and chondroitin sulfate to your regimen.

Glucosamine has been shown to increase sulfate uptake and boost synovial fluid production in joints (which provides lubrication and cushioning) and helps generate new cartilage by activating cells called chrondrocytes. These actions slow cartilage degeneration, repair connective tissue, and keep your joints moving smoothly. For best results take 1.5-2 g per day in 3 divided doses.

Chondroitin is a primary structural component of joint cartilage and is commonly combined with glucosamine to treat osteoarthritis and joint inflammation. For advanced weight-training athletes, using this combo is beneficial for treating and avoiding joint problems. Taking chondroitin with glucosamine helps you overcome these problems once they occur. But, even more important, taking them before injury occurs will help prevent it. For best results take 1-1.5 g per day divided in 3 doses.


What is the best supplement for increasing focus and training intensity?


Assuming that you are not sensitive to stimulants, then there is nothing better than caffeine for increasing focus and training intensity (with little to no side effects). Science supports caffeine as a highly effective ergogenic aid; thus, it stands to reason why most pre-workout powders contain high concentrations of it. Many athletes regularly use caffeine prior to training/competition to boost mental focus, combat fatigue, and decrease perceived exertion.

Caffeine acts on two levels, centrally (in the brain) and peripherally (in the body). In the brain, caffeine is a central nervous system stimulant that non-selectively blocks adenosine receptors. Normally (i.e, when caffeine isn’t available), adenosine binds to nerve cells and makes them slowdown in their activity. Caffeine is structured much like adenosine, so nerve cells readily allow caffeine to bind to their adenosine receptors, thus blocking the inhibitory action of adenosine on nerve activity. As a result, the caffeinated brain is profuse with “hyperactive” nerve cells. This hyperactive neuronal environment is perceived by the pituitary as an emergency, which results in adrenaline release from the anterior pituitary. At the same time, the brain increases the release of dopamine, which gives you the sense of well-being and focus.

In the body, caffeine inhibits an enzyme called phosphodiesterase (PDE). In cells PDE works to break down cyclic adenosine monophosphate (cAMP). cAMP is a very important cell signaling substance (called a second messenger) and caffeine stops the breakdown of cAMP, which prolongs and intensifies the stimulating effects of neurotransmitters and hormones in the body.


Research illustrates that 200-400 mg of caffeine taken 30-60 minutes before training will give you the greatest benefits.

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