Welcome to my weekly summary of the latest research from the world of sports science!
Is your watch underestimating your fitness? Should teens be taking creatine? And is caffeine actually boosting your WOD performance—or just giving you the jitters? This week’s research roundup looks at how Apple Watch VO₂ max tracking stacks up against lab tests, why creatine might be critical for youth development, and why caffeine didn’t deliver in a CrossFit setting—read on!
Smartwatch Fitness Estimates Miss the Mark
This study tested how accurately the Apple Watch Series 7 measures VO₂ max, a key metric for cardiovascular fitness. Participants wore the watch while also undergoing lab-based VO₂ max testing. The results showed the watch underestimated VO₂ max, especially in fitter individuals. While the Apple Watch may still be useful for tracking general fitness trends, it lacks the precision needed for serious athletic assessment.
My thoughts: Wearables like the Apple Watch can be helpful for spotting trends, but they’re no substitute for lab testing. If you're serious about performance, it's worth validating your data with more accurate methods.
Why Creatine Matters for Kids and Teens
This study tackled growing concerns about banning creatine supplements for minors. The authors push back, arguing that creatine is a naturally occurring compound essential for energy production and brain development—especially during adolescence. It's found in foods like meat and fish, and the body produces it naturally, but supplementing can support muscle function, cognitive development, and healthy growth. With over 680 studies confirming creatine’s safety and effectiveness, the authors suggest that limiting access due to outdated misconceptions could harm young athletes more than help them.
My thoughts: This is a bold move. It’s rare to see scientists push back against restrictions for minors unless the research is rock solid—and in this case, it is. Creatine isn’t just for bodybuilders; it’s a foundational nutrient for growing bodies. That’s why we include it in HMB+ Creatine—because the combination supports strength, recovery, and long-term muscle development at every stage of life.
Caffeine Does Not Improve Strength in CrossFit Workouts
This study examined whether caffeine improves performance in high-intensity CrossFit-style workouts. Twelve trained male athletes completed the same workout twice: once with caffeine, once with a placebo. The results showed no overall performance improvement with caffeine—and in some cases, performance actually declined, particularly in later rounds of sit-ups. Perceived effort and muscle damage markers were similar between conditions.
My thoughts: CrossFit and coffee go hand in hand, so this one may sting a little. That said, I wouldn’t count caffeine out just yet. I’d love to see this same study run on Hyrox athletes—my hunch is we’d get a very different result.
That’s all for this week! If you learned something new and are curious to know more, head over to the Blonyx Blog or my growing list of weekly research summaries where I help you further improve your athletic performance by keeping you up to date on the latest findings from the world of sports science.
– Train hard!
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