Pre-workout supplements(PWS)claimtoimprove strength andreduce fatiguewhiletraining.Many of these productsrely on the stimulant properties ofcaffeine(often in large doses)to produce thisperformance enhancement, yetaverificationof the caffeine content of theseproductshas never been conducted- until now.

In astudy, led byAssociate Professor Ben DesbrowfromGriffith University’s School of Allied Health Sciencesand published inDrug Testing and Analysis,15 popular PWSwereindependently assessedfor theircaffeine content. Results indicated thatthe caffeinecontainedwithin theseproducts differed considerablyfrom the product label,and thatapproximately half of the investigated PWS productsmayexpose consumers to potential caffeine related harms.

“We tested the caffeine content both within and between batches of the same product.Our values ranged fromapproximately 90 to almost 400mgin one serveof some pre-workout products,” says Associate Professor Desbrow.


A wide variation of caffeine content

“We found a wide variation of caffeine content, suggesting that consumers have the potential to be exposed to large and potentially dangerous doses of the stimulant.”

Public health recommendations for caffeine (Adults:single doses less than 200 mganddaily consumption less than 400 mg, Adolescents:less than3mg·kg-1ofbodyweight·day-1in younger individuals (e.g.lessthan185mg·day-1forthe average(62kg)16 year male),reflect concerns over the increased availability of caffeinated products and increases in the frequency of caffeine related adverse events (including sleeping disturbance, anxiety, cardiovascular events, seizures and death).

ThePWSdatawas also comparedto manufacturer reported values via the product information panels.

“We found thatproduct labelseitherdid notstatethe caffeine contentordid notprovide consumers with an accurate estimate of likely caffeine dose. At present, it is challengingfor any individual toensure they ingest safe and effective ergogenic doseof caffeinewhen taking a PWS.”

Associate Professor Desbrow says it is clear that the presence and severity of any potential side effects will relate to product choice and consumer eating patterns.

“The real concern comes when people take multiple doses of these products.Thisshould bediscouraged,asit isclearly not required from a sports performance perspectiveand may pose health risks.

“We needbehaviourialstudies to determine thefrequency withwhichconsumersrisk exposure to excessive caffeine intakesfrom these products.”