A new clinical trial published in June 2025 has cast doubt on the widely held belief that caffeinated, protein-based pre-workout supplements offer significant advantages over simpler carbohydrate-based options for those seeking strength and performance gains. The findings, which have generated significant interest and debate among fitness enthusiasts in Thailand and globally, suggest that many popular pre-workout formulas may be no more effective than consuming carbohydrates alone before hitting the gym [MensHealth].
The growing popularity of pre-workout supplements in Thailand mirrors global trends, with the market for such products expanding rapidly among young adults, fitness enthusiasts, and even middle-aged office workers. Marketing campaigns frequently claim that these supplements — often fortified with caffeine, protein, and a cocktail of other ingredients — can boost endurance, power, and muscle mass. However, the latest research challenges some of these assertions, making it crucial for Thai consumers to look past marketing hype and examine the evidence.
In the recent peer-reviewed study cited by both the Journal of the International Society of Sports Nutrition and summarized by leading health news outlets, 43 physically active, middle-aged individuals were recruited and randomly split into two groups. One received a caffeinated, protein-based pre-workout supplement while the other consumed a carbohydrate-only drink prior to their exercise sessions — both mixed with 400ml of water and taken 15 minutes before each workout. Over six weeks, participants engaged in regular resistance training, while researchers measured changes in body composition, waist and hip circumference, muscle thickness, strength, power output, and muscular endurance.
The results were illuminating: although the group receiving the caffeinated supplement saw a modest reduction in waist circumference, there were no significant differences between the two groups in improvements to isometric force, countermovement jump performance, medicine ball throw distance, or upper and lower body muscle endurance. Both groups experienced similar enhancements in these markers thanks to the training itself, not necessarily the supplement composition.
These findings suggest that, despite the thermogenic and ergogenic properties of caffeine—long touted as performance-enhancing—its benefit, at least in the context of multi-ingredient, protein-based pre-workouts versus carbohydrate-based ones, may be less significant than assumed. This is particularly relevant for Thai gym-goers and athletes who often consume such supplements; they may reconsider whether high-priced, heavily marketed formulas are delivering the promised edge.
Importantly, the researchers note that their conclusion does not mean caffeinated pre-workout supplements are ineffective; rather, in this study, they were not shown to outperform carb-only drinks. Several limitations are acknowledged, including the small sample size and the fact that participants already consumed three to five coffees or teas per day — a factor that could have influenced baseline caffeine tolerance and thus the study outcomes.
One of the principal investigators, affiliated with a UK sports nutrition research group, remarked: “We need further studies across a wider range of ages, activity levels, and dietary controls before drawing broad conclusions. Our findings highlight the need for skepticism towards supplement marketing and greater reliance on evidence-based choices.” This perspective is echoed by nutrition and sports science experts across the globe (Edge Hill University), who emphasize that while caffeine can reliably enhance endurance in some athletic contexts, its impact as part of multi-ingredient pre-workout formulas is less clear-cut.
Thailand’s growing fitness culture, influenced by global sports nutrition trends and aggressive product promotions, gives this study concrete relevance. Major gyms and retailers in Bangkok and other urban centers are flooded with pre-workout products, many at premium prices far above local carbohydrate-based sports drinks or simple foods such as bananas or rice. Thai exercise science officials with university affiliations regularly caution that, in most cases, adequate carbohydrate intake and hydration before training are more cost-effective and just as beneficial as high-priced supplements.
Cultural attitudes in Thailand also play a role. While traditional Thai dietary practices offer natural avenues for pre-exercise nutrition—for instance, sticky rice with ripe bananas or sweet potatoes—these options are sometimes overlooked amid the growth of global supplement brands promising rapid gains. With Thailand’s GDP per capita placing severe pressure on many fitness consumers, re-examining the necessity of expensive imported supplements takes on renewed importance.
In addition, the global sports nutrition market—estimated by Euromonitor to be worth US$28 billion in 2024—remains largely unregulated, including in Thailand. Unlike medicines, dietary supplements often escape the rigorous oversight of regulatory bodies. Thai health officials and consumer protection advocates stress the importance of consulting certified trainers or sports nutritionists before starting any supplementation program, particularly given the prevalence of counterfeit or adulterated products found in Southeast Asian markets.
Another aspect worth considering is the placebo effect, which can be powerful in sports performance. As the International Society of Sports Nutrition has previously noted (PMC7777221), simply believing in the efficacy of a supplement can improve performance, independent of physiological mechanisms. Thus, the psychological aspect of pre-workout rituals may partly explain why so many Thai athletes report positive experiences, even if scientific evidence remains equivocal.
While the present study focused on middle-aged adults, athletic high school and university students in Thailand—who increasingly participate in resistance training—may be tempted by aggressive supplement marketing. Physical education lecturers at leading Thai universities warn that adolescent bodies may respond differently to both caffeine and protein loads, raising the need for age-appropriate guidance and further research.
Looking ahead, the researchers advocate for more extensive studies that include dietary controls, diverse populations (including Thai participants, whose baseline diets and caffeine consumptions may differ from Western cohorts), and longer duration to fully elucidate the impact of pre-workout formulas. Additional investigation into single-ingredient (caffeine alone, for example) versus multi-ingredient supplements would help clarify which, if any, components truly drive performance benefits.
For ordinary Thai readers considering supplementation, the actionable advice is clear: don’t abandon your routine if a caffeinated pre-workout works for you, but don’t assume it is automatically superior to a bowl of kao tom or a sweet potato and an isotonic drink. If cost is a factor, remember this research suggests carbohydrate drinks or foods may perform just as well. Always check with a qualified health professional before adding new supplements to your regimen. And, given the proliferation of social media influencers and supplement ads, remember that the best results still come from consistent training, good nutrition, adequate sleep, and evidence-based decision-making.
For consumers and athletes across Thailand’s gyms and sports communities, this study serves as a timely reminder: cutting-edge supplements may not always provide cutting-edge results. Seek credible information, value traditional Thai nutrition, and consult experts before purchasing expensive products whose benefits may not reflect their price tag.
Citations:
- Why Your Caffeinated Pre-Workout Might Be Useless, According to New Study (Men’s Health)
- Pre-Workout Supplements and Their Effects on Cardiovascular Health (PMC12028264)
- International Society of Sports Nutrition Position Stand: Caffeine and Performance (PMC7777221)
- Pre-Workout Supplements: Why Five of the Six Most Common Ingredients Probably Aren’t Helping You (Edge Hill University)