Walk into any gym or health food store and you’ll be greeted by shelves lined with powders, pills, and promises. Sports supplements are a multi-billion dollar industry, but do they actually make a difference? The short answer: maybe, but not in the way most marketing would have you believe.
Before we even talk about supplements, the most important thing to understand is that no supplement can out-perform a poor diet. If your meals aren’t providing adequate energy, protein, carbohydrates, and micronutrients to support your training, adding a pre-workout or protein powder on top won’t fix that. Getting your nutrition fundamentals right, eating enough whole foods, staying hydrated, and fuelling around your training, will deliver far greater results than any supplement ever will. Think of supplements as a small potential boost on top of an already solid foundation, not a shortcut.
The Australian Institute of Sport (AIS) has developed one of the most respected frameworks for evaluating sports supplements in the world. Their ABCD Classification System ranks sports foods and supplement ingredients into four groups based on scientific evidence and practical considerations, asking whether a product is safe, permitted, and effective in improving sports performance.
Here’s a simple breakdown:
Group A — Supported for use in specific situations with strong scientific evidence. These are the supplements that have actually earned their place, including sports drinks, caffeine, creatine, and iron (when deficient).
Group B — Deserve further research and can be considered under the guidance of a professional. The evidence is promising but not yet conclusive.
Group C — Little to no proof of benefit. Many popular products on store shelves fall here. Save your money.
Group D — Banned or high risk of containing prohibited substances. Athletes should avoid these entirely.
Here are some of the most commonly discussed supplements and where they sit in the evidence:
It is worth noting that all of the Group A supplements above require specific doses to be effective. Taking too much or too little can mean you see no benefit at all, or in some cases cause unwanted side effects. This is exactly why consulting an Accredited Sports Dietitian before starting any supplement is so important. They can guide you on the right amounts for your body, your sport, and your goals.
Only a few supplements, including caffeine, creatine, specific buffering agents and nitrate, have good evidence of benefits, and even then, responses can vary widely between individuals. Most products are targeting your wallet more than your performance.
Before reaching for supplements, speak with an Accredited Sports Dietitian. They can assess whether you actually have a gap in your nutrition, recommend evidence-based options, and ensure you are taking the right supplement in the right amount at the right time. Supplements can play a small role, but only once the basics are nailed.
Australian Institute of Sport. (2024). AIS Sports Supplement Framework. Australian Sports Commission. https://www.ausport.gov.au/ais/nutrition/supplements
