Welcome to my weekly summary of the latest research from the world of sports science!
This week’s research roundup dives into how your environment, nutrition, and recovery strategy directly impact performance. We cover why training in the heat increases carb demand even if you’re hydrated, how large doses of whey protein can spike insulin almost like sugar, and why cold-water immersion outperforms massage for short-term recovery—especially after brutal workouts like Murph—read on.
Heat and Dehydration Make You Burn Through Carbs Faster
This meta-analysis pooled 18 studies on running and cycling in hot conditions, examining markers like blood glucose, lactate, respiratory exchange ratio, and muscle glycogen use. Across the board, exercising in the heat increased reliance on carbohydrates for fuel, even when hydration levels were matched. Dehydration made the effect worse. Though mechanisms are still being explored, researchers suspect that reduced blood volume in the heat limits oxygen delivery, forcing muscles to shift to faster-burning carbs for fuel.
My thoughts: This helped me understand why summer training feels so much harder. Your body burns through carbs faster in the heat—especially if you’re even mildly dehydrated. The theory makes sense: less blood volume means less oxygen delivery, so muscles shift to carbs. Another reason to stay hydrated with an electrolyte drink mix like Hydra+ that provides both electrolytes and some carbohydrates when training in hot weather.
Whey Protein Can Spike Insulin the Same Way Sugar Does
This study tested how large, single servings of whey protein or sucrose affect hormones and metabolites in healthy adults. After ingestion, researchers tracked blood glucose, insulin, glucagon, amino acids, and nitrogen excretion. Surprisingly, whey protein spiked insulin almost as much as sugar did. The difference? Instead of high blood sugar, the trigger was high blood amino acids, which also stimulate insulin release. For athletes, this insulin effect can be a positive—enhancing recovery if timed after workouts—but it might not be ideal at other times of day.
My thoughts: Geeky but useful. Whey protein causes an insulin spike almost as big as sugar—not because of blood glucose, but because of amino acids. I recommend saving fast-digesting protein for post-training, when your body is primed to use it for repair. Otherwise, it’s a bit like eating candy.
Cold Plunges Beat Massages for Faster Recovery
This study compared cold-water immersion with massage in 24 CrossFit athletes after the brutal Murph workout (1 mile run, 100 pull-ups, 200 push-ups, 300 squats, then another mile run). Researchers tracked soreness, fatigue, and recovery of performance over 72 hours. Both methods helped, but cold water immersion was better in the short term, with athletes recovering strength faster and reporting less soreness at 24–48 hours. By 72 hours, both groups had mostly recovered.
My thoughts: Cold water immersion is better than massage—at least if you’re a CrossFitter. This confirms what a lot of athletes already feel. For tough sessions like Murph, jumping in a tub might be your fastest way back to baseline.
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!
Looking for more ways to keep up with Blonyx?
Now, you can join the Blonyx Strava Club to track your progress, share training tips, and connect with athletes who share your athletic ambition.
You can also follow us on Instagram and Facebook for additional sports science information, announcements, exciting giveaways, and more!