Athletic Greens & Supplements: Separating Research from Marketing Hype

Walk into any supplement store or scroll through a fitness influencer’s feed, and you’ll be met with a dizzying array of products promising everything from explosive power to effortless recovery. The global sports nutrition market was valued at over $45 billion in 2024 and shows no signs of slowing down. But here’s the uncomfortable truth that rarely makes it into the marketing: for the vast majority of supplements on the shelf, robust scientific evidence supporting their performance claims is limited or nonexistent.

That doesn’t mean all supplements are useless. Some have genuine, well-documented benefits backed by decades of randomized controlled trials. The challenge is telling them apart from the ones that look impressive on a label but deliver little in practice. This article is designed to help you do exactly that — by introducing a credible evidence-based framework, explaining an industry practice worth understanding, and walking through what the research actually says about some of the most popular ingredients in sports nutrition.

A Credibility Framework: The AIS ABCD Classification

One of the most respected tools for evaluating sports supplements is the ABCD Classification System developed by the Australian Institute of Sport (AIS). Rather than relying on marketing claims, this framework ranks individual supplement ingredients into four groups based on scientific evidence, safety, and whether they are permitted for use in sport.

Group A includes supplements with strong scientific evidence supporting their use in specific sporting situations, with established protocols for safe and effective use. Group B includes supplements with emerging scientific support that deserve further research but are not yet proven. Group C includes supplements with little meaningful evidence of benefit or insufficient research to form an informed opinion. Group D includes substances that are banned or carry a high risk of contamination with prohibited compounds.

The AIS framework is notable for several reasons. It evaluates individual ingredients rather than branded products, it is regularly updated as new research emerges, and it is endorsed by the International Olympic Committee’s 2018 consensus statement on supplements and the high-performance athlete. Throughout this article, we’ll reference this framework to provide context for each ingredient discussed.

Fairy Dusting: The Label Practice Every Consumer Should Understand

Before we dive into specific ingredients, there’s an industry practice worth understanding: “fairy dusting.” Originally coined in the cosmetics industry, the term has been adopted in the supplement world to describe the practice of including a tiny, sub-therapeutic amount of a popular ingredient in a product — just enough to list it on the label, but far too little to have any meaningful biological effect.

Fairy dusting is made possible by a labelling convention known as the “proprietary blend.” When ingredients are grouped into a proprietary blend, the manufacturer is required to list the total weight of the blend and the individual ingredients in descending order of weight, but not the specific amount of each ingredient. This means a product could list an impressive roster of twenty ingredients while containing meaningful amounts of only two or three — with the rest present in trace quantities that would have no effect at any dosage studied in clinical research.

The AIS itself has flagged this concern. On their official framework page, they note that multi-ingredient supplements raise specific concerns including the lack of an effective dose of some active ingredients, potential for harmful interactions between ingredients, and the increased risk of contamination due to the sourcing of ingredients from various locations.

How to spot potential fairy dusting: Look for products that list every ingredient with its specific dosage rather than hiding behind a proprietary blend. Check whether the total blend weight is realistic given the number of ingredients listed, a blend of 30 ingredients totalling 60 milligrams means you’re getting an average of 2 milligrams per ingredient, which is almost certainly below any clinically studied dose. And be cautious of products that list more than a dozen trendy ingredients but don’t disclose how much of each you’re actually getting.

Group A: Supplements with Strong Scientific Evidence

Creatine Monohydrate

The claim: Increases strength, power, and muscle mass.

What research shows: Creatine is arguably the most extensively studied sports supplement in history. It works by replenishing phosphocreatine stores in muscle, which helps regenerate ATP — the primary energy currency for short, explosive efforts. Hundreds of peer-reviewed studies and multiple meta-analyses consistently show that creatine supplementation (typically 3–5 grams per day) improves performance in high-intensity, short-duration activities such as sprinting, weightlifting, and repeated-effort sports. It is also associated with increased lean body mass. The International Society of Sports Nutrition considers creatine monohydrate the most effective nutritional supplement for increasing high-intensity exercise capacity and lean body mass.

The reality: Creatine’s benefits are genuine, well-documented, and not limited to bodybuilders. It is one of the few supplements that consistently delivers on its core claims. It is also one of the most affordable. Long-term safety data is reassuring, with studies spanning several years showing no adverse effects on kidney or liver function in healthy individuals.

Caffeine

The claim: Improves focus, energy, endurance, and power output.

What research shows: Caffeine is the most widely used psychoactive substance in the world and one of the most studied ergogenic aids. Systematic reviews of elite athletes confirm that acute doses of 3–6 mg per kilogram of body mass, taken 30–60 minutes before exercise, consistently improve sprint performance, power output, endurance, and technical skills. The mechanisms are well understood: caffeine antagonizes adenosine receptors in the brain, reducing perceived effort and fatigue while enhancing alertness and focus.

Worth noting: Caffeine can come from many natural sources. Matcha green tea provides caffeine alongside L-theanine, an amino acid that has been studied for its potential to promote a state of calm alertness without the jitteriness some people experience from coffee. This caffeine-L-theanine combination is an active area of research, with several small trials suggesting synergistic effects on attention and cognitive performance, though larger studies are needed.

Beetroot Juice / Dietary Nitrate

The claim: Enhances endurance by improving oxygen efficiency.

What research shows: Beetroot is a dense source of inorganic nitrates, which the body converts into nitric oxide (NO). Nitric oxide plays a role in vasodilation (widening of blood vessels), blood flow regulation, and mitochondrial efficiency. Multiple studies have shown that dietary nitrate supplementation can reduce the oxygen cost of exercise, effectively making submaximal exercise feel easier. Typical research protocols use approximately 300–500 mg of nitrate taken 2–3 hours before exercise.

The nuance: The benefits appear strongest in recreational and moderately trained athletes. In highly trained elite athletes, the effects are less consistent, possibly because their bodies are already highly efficient at producing and utilizing nitric oxide. Researchers suggest that elite athletes may need different dosing strategies or longer supplementation periods.

Beta-Alanine

The claim: Delays fatigue during high-intensity exercise.

What research shows: Beta-alanine combines with histidine in the body to form carnosine, a molecule that buffers hydrogen ions in working muscles. This buffering helps delay the acidic environment that contributes to muscular fatigue. Research shows significant performance improvements in activities lasting approximately 1–4 minutes — the window where acid accumulation is most performance-limiting. Typical dosing is 2–6 grams daily in divided doses, with a loading period of several weeks needed to elevate muscle carnosine levels.

What it doesn’t do: Beta-alanine is unlikely to improve performance in very short efforts (under 60 seconds) or very long endurance events where acid buffering is not the primary limiting factor. The tingling sensation (paresthesia) some people experience is harmless but can be startling if unexpected.

Popular But Nuanced: Supplements That Need Context

BCAAs (Branched-Chain Amino Acids)

The claim: Reduce muscle soreness and support recovery.

What research shows: BCAAs (leucine, isoleucine, and valine) are essential amino acids that play a role in muscle protein synthesis. However, the consensus among sports nutrition researchers is that BCAA supplementation is largely unnecessary for individuals who consume adequate protein from their diet — typically 1.6–2.2 grams per kilogram of body weight per day for active individuals. Complete protein sources already contain all the BCAAs you need, along with the other essential amino acids required for a full muscle protein synthesis response.

The reality: For most people eating a reasonable diet, BCAAs are an expensive way to get something they’re already getting from food. They may have a niche role for athletes training fasted or those with very restricted diets, but for the general population, spending on BCAAs would be better directed toward whole food protein sources.

Greens Powders

The claim: Provide the nutritional equivalent of multiple servings of fruits and vegetables in a single scoop.

What research shows: Greens powders have become one of the fastest-growing supplement categories, with brands like AG1 (formerly Athletic Greens) helping to popularize the format through extensive influencer marketing. AG1, which contains 75+ ingredients, has begun funding its own clinical trials — a positive step toward evidence-based transparency in a category that has historically lacked independent research. Their early studies have shown effects on nutrient biomarkers and gut microbiome composition, though these are still in the early stages of the clinical research lifecycle.

The nuance: While greens powders can provide vitamins, minerals, and phytonutrients, independent research on the category as a whole remains limited. Most importantly, no greens powder provides the same fiber content, bioavailability, or satiety as eating actual whole fruits and vegetables. Sports dietitians and nutrition researchers consistently emphasize a “food first” approach, with supplements serving as a complement to, not a replacement for, a well-balanced diet. When evaluating any greens powder, it’s worth checking whether individual ingredient amounts are disclosed or whether they are grouped into proprietary blends — and whether the total blend weights are realistic given the number of ingredients listed.

Collagen Peptides

The claim: Support joint health and recovery.

What research shows: Collagen peptides have surged in popularity for joint and connective tissue support. Some studies, including a notable trial using gelatin with vitamin C before exercise, have shown promising results for collagen synthesis in tendons and ligaments. However, the overall evidence base is still developing, with many studies being small, short-term, or industry-funded. The mechanisms by which ingested collagen peptides might specifically target joint tissue (as opposed to being broken down into generic amino acids) are still debated among researchers.

Emerging Research: Ingredients Worth Watching

Beyond the established evidence base, several natural ingredients are generating genuine scientific interest for their potential roles in exercise performance, recovery, or overall athletic wellness. None of these have reached the evidence threshold of Group A, but the early research is worth understanding.

L-Theanine (Especially Combined with Caffeine)

L-theanine, an amino acid found naturally in tea leaves and particularly concentrated in matcha, has been studied for its effects on cognitive function and relaxation. When paired with caffeine — as it naturally occurs in matcha — small trials suggest the combination may promote sustained attention without the anxiety spike some people experience from caffeine alone. This is an active area of research with promising but preliminary findings.

Dietary Nitrate from Whole Foods

While beetroot juice is the most studied source, dietary nitrate is naturally present in many leafy greens and root vegetables, including spinach, kale, and beetroot. Research into the broader benefits of nitrate-rich diets (as opposed to isolated supplementation) is growing, with observational studies suggesting cardiovascular and exercise performance associations. The distinction between whole-food nitrate sources and concentrated supplements is an important area of ongoing investigation.

Polyphenols and Anthocyanins

Compounds found in blueberries, grape skins, tart cherries, and other deeply pigmented fruits have attracted research attention for their antioxidant properties and potential to modulate exercise-induced inflammation and oxidative stress. Tart cherry juice, in particular, has been studied in several small trials for muscle soreness and recovery, with mixed but generally positive results. Blueberry anthocyanins and grape skin polyphenols (including resveratrol) are also being investigated, though human performance studies remain limited.

Lion’s Mane Mushroom

Lion’s mane (Hericium erinaceus) contains unique compounds called hericenones and erinacines that have shown neuroprotective and cognitive-supporting properties in preclinical research. While it is not directly studied as a sports performance ingredient, the growing interest in cognitive function, focus, and “brain-body” performance in athletic contexts has placed it on the radar of sports nutrition researchers. Human clinical evidence is still in its early stages.

Ashwagandha for Recovery

As we explored in a previous article, ashwagandha (Withania somnifera) has been studied for its effects on cortisol, stress, and recovery. Some RCTs have shown modest improvements in VO₂max and recovery markers in athletic populations, though the evidence base is still small. The adaptogenic herb sits in an interesting space between traditional use and emerging modern evidence.

Probiotics for Athletic Health

Emerging research suggests that specific probiotic strains may support immune function and reduce the incidence of upper respiratory tract infections in athletes during heavy training periods. Some studies have also explored probiotic effects on exercise tolerance and fatigue prevention. Spore-forming strains like Bacillus coagulans have attracted particular interest because of their stability and survival through the digestive system.

How to Read a Supplement Label Like a Scientist

Armed with an understanding of the evidence landscape and the fairy dusting phenomenon, here are practical guidelines for evaluating any sports supplement:

Check for ingredient transparency. Every active ingredient should be listed with its specific amount per serving — not hidden inside a proprietary blend. If a product doesn’t tell you how much of each ingredient you’re getting, you cannot evaluate whether the dose is meaningful.

Compare doses to research. For well-studied ingredients, the effective doses are well established: creatine at 3–5 grams per day, caffeine at 3–6 mg/kg body weight, beta-alanine at 2–6 grams per day, dietary nitrate at 300–500 mg before exercise. If a product contains these ingredients at doses far below these ranges, the label may look good without delivering results.

Be skeptical of ingredient lists that are too long. More ingredients does not mean more effective. In fact, the more ingredients packed into a single product, the harder it is to include meaningful doses of each one — especially in a small serving size. A focused product with five well-dosed ingredients is likely more effective than a product with fifty underdosed ones.

Look for third-party testing. Independent certification (such as Informed Sport, NSF Certified for Sport, or equivalent programs) provides assurance that the product contains what it claims and is free from banned substances. This is especially important for competitive athletes.

Apply the “food first” principle. The International Olympic Committee, the AIS, and virtually every major sports nutrition organization emphasizes that supplements should complement a well-balanced diet, not replace it. Many of the compounds found in supplements — nitrate, polyphenols, anthocyanins, fiber, vitamins, and minerals — are naturally present in whole foods like leafy greens, berries, root vegetables, and fermented foods. A diverse, nutrient-dense diet is the foundation; supplements are the fine-tuning.

The Bottom Line

The sports supplement industry is enormous, growing, and largely driven by marketing rather than evidence. But within it, there are ingredients with genuine, well-documented benefits — and many more that are popular without being proven. The AIS ABCD framework offers a clear, evidence-based lens for separating the two.

The most important takeaway is not that supplements are good or bad, but that the quality of evidence matters enormously. Creatine and caffeine have decades of robust research behind them. Greens powders and many multi-ingredient formulas are still catching up. Emerging ingredients like L-theanine, polyphenols, lion’s mane, and specific probiotics are generating real scientific interest, but the evidence is early and evolving.

Being an informed consumer means looking beyond the marketing, checking the label for transparency and meaningful doses, and remembering that no supplement can replace the fundamentals: a balanced diet, consistent training, adequate sleep, and effective stress management. The science will continue to evolve — and the best approach is to evolve with it, guided by evidence rather than hype.

As always, consult with a qualified healthcare professional or accredited sports dietitian before making significant changes to your supplement routine, especially if you are a competitive athlete or managing a health condition.

Disclaimer: This article is for educational and informational purposes only. It is not intended to diagnose, treat, cure, or prevent any disease, nor does it constitute an endorsement of any specific product or brand. The information provided does not constitute medical or dietary advice. Always consult with a qualified healthcare professional regarding any health concerns or before making changes to your diet, lifestyle, or supplement routine.

Selected References:

Australian Institute of Sport. ABCD Classification System — AIS Sports Supplement Framework. ausport.gov.au/ais/nutrition/supplements

Maughan, R.J. et al. (2018). IOC consensus statement: dietary supplements and the high-performance athlete. International Journal of Sport Nutrition and Exercise Metabolism, 28(2), 104–125.

Kreider, R.B. et al. (2017). ISSN position stand: safety and efficacy of creatine supplementation. Journal of the International Society of Sports Nutrition, 14, 18.

Guest, N.S. et al. (2021). ISSN position stand: caffeine and exercise performance. Journal of the International Society of Sports Nutrition, 18, 1.

Jones, A.M. (2014). Dietary nitrate supplementation and exercise performance. Sports Medicine, 44(S1), 35–45.

Saunders, B. et al. (2017). Beta-alanine supplementation to improve exercise capacity and performance: a systematic review and meta-analysis. British Journal of Sports Medicine, 51(8), 658–669.

Peeling, P. et al. (2018). Evidence-based supplements for the enhancement of athletic performance. International Journal of Sport Nutrition and Exercise Metabolism, 28(2), 178–187.

Burke, L.M. et al. (2019). Supplements and sports foods. In Clinical Sports Nutrition (5th ed., pp. 493–582). McGraw-Hill Education.